Test 1 Flashcards

Question

Monomer

Answer 1

The subunit that serves as the building block of a polymer.

Answer 2

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Answer 3

A chemical reaction that breaks apart a larger molecule by adding a molecule of water.

Answer 4

A polpeptide chain formed of 20 different amino acids. Diverse size and shape, the shape or structure determines the function of the protein. The body's building block. Provide structure, can act as enzymes, transport, gene expression, and immune response.

Answer 5

The monomer of proteins. Bonded together amino acids are called polypeptides.

Answer 6

Isomers that are mirror images of each other.

Answer 7

Energy of motion.

Answer 8

Energy cannot be created or destroyed.

Answer 9

Every energy transfer or transformation increases the entropy of the universe.

Answer 10

Chemical reactions that release energy.

Answer 11

A chemical reaction that requires energy imput.

Answer 12

A state of balance.

Answer 13

Acceleration of the rate of a chemical reaction due to a decrease in the free energy of the transition state, called the activation energy.

Answer 14

Catalysts for chemical reactions in living things.

Answer 15

The minimum amount of energy required to start a chemical reaction.

Answer 16

Simple molecules became more complex becoming cells, became able to make a copy of oneself and surrounded by cell membrane.

Answer 17

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Answer 18

A base of nucleic acids. Pairs with Guanine

Answer 19

A base of nucleic acids found in RNA. Pairs with Adenine.

Answer 20

A base of nucleic acids in DNA. Pairs with Adenine.

Answer 21

Base of nucleic acids. Pais with cytosine.

Answer 22

Base of nucleic acids. In DNA pairs with Thymine. In RNA pairs with Uracil.

Answer 23

Procedure used to separate and analyze DNA fragments by placing a mixture of DNA fragments at one end of a porous gel and applying an electrical voltage to the gel.

Answer 24

A complex molecule containing the genetic information that makes up the chromosomes. A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.

Answer 25

A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses. Carries genetic information that is translated by ribosomes into various proteins necessary for cellular processes. Information from DNA to ribosomes.

Answer 26

The starting point of the strand when you write it out from left to right. The 5' end is important because it dictates the direction in which the DNA or RNA strand is synthesized and how it is read during processes like replication and transcription.

Answer 27

In other words, it's the end of the strand opposite the 5' end. The 3' end is crucial because it plays a significant role in the processes of DNA replication and RNA transcription, as nucleotides are added to this end during synthesis.

Answer 28

SD/√n SD: Standard Deviation -------------------------------- √n: Sample Size

Answer 29

A computed measure of how much scores vary around the mean score.

Answer 30

The 2 underlying theories of biology are Cell Theory and the Theory of Evolution. Both share the opinion that life is very interconnected and diverse, that cells and species can replicate and evolve, and both are supported by scientific evidence.

Answer 31

There is a lot of evidence and the theory has been validated across many different organisms. Has failed to be disproved.

Answer 32

Hypothesis: A testable prediction Fact: Observation that can be verified Theory: Well-sustained explanation that hase been failed to disprove. Theories are not just opinions but continuously tested frameworks.

Answer 33

Phylogenetics provide information into common ancestry and evolution.

Answer 34

Natural selection is one of the key processes that drives evolution while the theory of evolution encompasses mechanisms like genetic drift, mutations, and gene flow.

Answer 35

It is a sharing element. It can form stable covalent bonds with many other atoms. Can bond to itself to create long carbon chains and rings, and they're very stable yet reactive enough to create biochemical reactions. CARBON: AKA BACKBONE OF LIFE

Answer 36

It suggests the potential for life.

Answer 37

Water is polar, solutes dissolve in water, its ability to participate in hydrogen bonds gives it a high heat capacity, and it can spontaneously dissassociates into hydrogen ions (H+) and hydroxide ions (OH-).

Answer 38

Because living things are all carbon based.

Answer 39

Amino Acids.

Answer 40

Nucleotides. Nucleotides consist of a nitrogenous base, a 5-carbon sugar, and a phosphate group.

Answer 41

Polymerization: the bonding together of monomers, usually water is the byproduct.

Answer 42

Enzymes that unzip the bonds or Hydrolysis, where water is added.

Answer 43

Enzyme Activity Transport Structure Immune REsponse Signaling Movement Storage

Answer 44

The shape.

Answer 45

Primary Structure: Peptide Bonds Secondary Structure: Hydrogen bonding and Peptide Bonds Tertiary Structure: Peptide Bonds, Hydrogen Bonds, Covalent, and Ionic bonds Quaternary Structure: Bonds and Interactions iwth the R Group

Answer 46

Lowering Activation Energy

Answer 47

Substrate orientation. Facilitate collisions and therefore bond formation.

Answer 48

Competitive Inhibition and Allosteric Regulation.

Answer 49

Depending on optimal pH, tmeperature, and substrate concentrations the enzymes can function at different levels of productivity.

Answer 50

2 antiparalell strands Nucleotides Base Pairing Sugar Phosphate Background Major and Minor Grooves

Answer 51

One strand runs in the 5' to 3' direction, meaning it starts with a phosphate group at the 5' end and ends with a hydroxyl group at the 3' end. The other strand runs in the 3' to 5' direction, starting with a hydroxyl group at the 3' end and ending with a phosphate group at the 5' end. This is important for base pairing, replication, and stability.

Answer 52

he 5' end has a phosphate group attached to the fifth carbon of the sugar (deoxyribose). The 3' end has a hydroxyl group attached to the third carbon of the sugar. REad the sequence and see if it starts with 5' or 3'.

Answer 53

PMore efficent binding, replication, and repair.

Answer 54

Yes it can store information. No it does nnot have catalytic properties, it can interact with catalytic orotein but not independently catalyze reactions.

Answer 55

Yes, not as much information as DNA though. Yes, some RNA, known as ribozymes can catalyze reactions. This id due to RNA less structured shape and many forms which can form into many different shapes, so amnt different functions,

Answer 56

Single Stranded RNA Secondary Structures (hairpins, loops) Tertiary Structures rRNA tRNA

Answer 57

BOTH -Nucleotide Base Pairing -Contain Genetic Info -Involved in Protein Synthesis DNA -Deoxyribose -Double Stranded, helix structure -Has Base Thymine -Long term genetic infostorage -Super stable RNA -Ribose -Single Stranded -Uracil Base -Messenger, Transger, and ribosomal roles -Less stable due to extra hydroxyl group

Answer 58

Formed by linking monosaccharides to form polysaccharides

Answer 59

Sugar monomers that make up polysaccharide chains

Answer 60

Chains of monosaccharides that form proteins.

Answer 61

A protein with one or more carbohydrates covalently attached to it.

Answer 62

Adenine TriPhosphate primary energy carrier in cells. For energy transfer within cells.

Answer 63

Polymers of fatty acids. Store energy in C--C and C--H bonds. Structural role. Fat in animals serves as insulation.

Answer 64

A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached. Muscle growth.

Answer 65

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

Answer 66

Lipid type that is solid at room temp. MAd eof triglycerides, store energy, provide insulation, and protection.

Answer 67

Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration, resulting in a net movement until equilibrium is reached.

Answer 68

Facilitated diffusion utilizes transport proteins to assist the movement of larger or polar molecules (like glucose or ions) across the membrane. This process does not require energy, as it relies on the concentration gradient, moving substances from areas of higher concentration to areas of lower concentration until equilibrium is reached.

Answer 69

Passive transport is the movement of molecules across a cell membrane without the expenditure of energy. This process occurs along the concentration gradient, meaning substances move from areas of higher concentration to areas of lower concentration.

Answer 70

Active transport is the movement of molecules across a cell membrane against their concentration gradient, from areas of lower concentration to areas of higher concentration. Unlike passive transport, active transport requires energy, usually in the form of ATP, to drive the process.

Answer 71

The diffusion of water across a selectively permeable membrane.

Answer 72

Isotonic refers to a solution that has the same concentration of solutes as another solution, typically compared to the inside of a cell. In an isotonic environment, there is no net movement of water into or out of the cell, meaning the cell maintains its normal shape and function.

Answer 73

Hypertonic refers to a solution that has a higher concentration of solutes compared to another solution, typically in relation to the inside of a cell. Cell shrivels becuase the higher concentration leaves. Same in animal and plants.

Answer 74

Hypotonic refers to a solution that has a lower concentration of solutes compared to another solution, typically in relation to the inside of a cell. Cel swells and bursts in animals, in plants it is more resitant to bursting due to the need for water and long term hydration storage in plants (the cell wall).

Answer 75

Prokaryotes are single-celled organisms that lack a membrane-bound nucleus and other membrane-bound organelles. Small, simple, and asexual cells. Bacteria and Archaea

Answer 76

A plasmid is a small, circular piece of DNA that exists independently of the chromosomal DNA within a cell. Plasmids are primarily found in prokaryotic organisms, such as bacteria, but can also be present in some eukaryotic cells. functions: resitance to antibiotics enabling bacteria, caarry genes that enhance the pathogenicity of bacteria

Answer 77

A eukaryote is an organism whose cells contain a nucleus and other membrane-bound organelles. Visible, multicellular organisms.

Answer 78

The cell membrane, also known as the plasma membrane, is a biological barrier that surrounds and protects the cell, controlling the movement of substances in and out. Composed of the phospolipid bilayer, contains protein (receptors, enzymes, and transport). Enables selective permeability, communication, structure, and transport.

Answer 79

Membrane bound oranelle found in eukaryotic cells that is the control center of the cell. Houses genetic material.

Answer 80

A ribosome is a complex molecular machine found in all living cells that is essential for protein synthesis (translation). Ribosomes can be found either floating freely in the cytoplasm or attached to the endoplasmic reticulum (in eukaryotic cells), forming what is known as the rough ER.

Answer 81

The smooth endoplasmic reticulum (smooth ER) is a type of endoplasmic reticulum (ER) that lacks ribosomes on its surface, giving it a smooth appearance. It plays several important roles within the cell. Lipid Synthesis Detoxification Calcium storage Metabolism of carbs

Answer 82

The rough endoplasmic reticulum (rough ER) is a type of endoplasmic reticulum characterized by the presence of ribosomes on its surface, giving it a "rough" appearance. It plays a crucial role in the synthesis and processing of proteins. Protein synthese Protein folding Quality control

Answer 83

The Golgi apparatus, also known as the Golgi complex or Golgi body, is a vital organelle in eukaryotic cells responsible for modifying, sorting, and packaging proteins and lipids for secretion or delivery to various cellular destinations. UPS

Answer 84

A lysosome is a membrane-bound organelle found in eukaryotic cells that contains digestive enzymes. These enzymes are responsible for breaking down waste materials, cellular debris, and foreign substances.

Answer 85

A peroxisome is a small, membrane-bound organelle found in eukaryotic cells that plays a crucial role in lipid metabolism and the detoxification of harmful substances.

Answer 86

A vacuole is a membrane-bound organelle found in the cells of plants, fungi, and some protists. Animals don't have. Play a role in storage, structure, regulation, and degradation

Answer 87

Mitochondria are membrane-bound organelles found in eukaryotic cells, often referred to as the "powerhouses" of the cell. They generate adenosine triphosphate (ATP) through cellular respiration, providing energy for various cellular processes. Mitochondria also play roles in regulating metabolism, apoptosis, and maintaining cellular homeostasis.

Answer 88

Chloroplasts are membrane-bound organelles found in the cells of plants and some algae, responsible for photosynthesis. They contain chlorophyll, the pigment that captures light energy, allowing the conversion of carbon dioxide and water into glucose and oxygen. In addition to energy production, chloroplasts play a role in synthesizing certain nutrients and regulating plant metabolism.

Answer 89

The extracellular matrix (ECM) is a complex network of proteins and carbohydrates that provides structural and biochemical support to surrounding cells in tissues. It plays a crucial role in cell adhesion, migration, and communication, influencing processes such as tissue development and repair. The ECM also helps maintain tissue integrity and regulates cellular functions through various signaling pathways.

Answer 90

The cytoskeleton is a dynamic network of protein filaments and tubules that provides structural support, shape, and organization to eukaryotic cells. It is composed of three main components: microfilaments, intermediate filaments, and microtubules, each serving different functions in cell movement, division, and intracellular transport. Additionally, the cytoskeleton plays a critical role in maintaining cell integrity and facilitating communication between cells.

Answer 91

Actin is a globular protein that polymerizes to form long, thin filaments known as microfilaments, which are a key component of the cytoskeleton in eukaryotic cells. It plays crucial roles in various cellular processes, including muscle contraction, cell shape maintenance, and cell motility. Actin filaments also participate in intracellular transport and are involved in signaling pathways that regulate cell division and other functions.

Answer 92

Microtubules are cylindrical structures made of tubulin protein subunits that form part of the cytoskeleton in eukaryotic cells. They provide structural support, shape the cell, and are essential for cell division by forming the mitotic spindle that segregates chromosomes. Additionally, microtubules serve as tracks for the movement of organelles and vesicles within the cell, facilitating intracellular transport.

Answer 93

Centrioles are cylindrical organelles found in animal cells, typically occurring in pairs, and play a key role in cell division. They are involved in organizing microtubules to form the mitotic spindle, which helps segregate chromosomes during mitosis and meiosis. Centrioles also contribute to the formation of cilia and flagella, which are important for cell movement and fluid movement across cell surfaces.

Answer 94

Cilia and flagella are hair-like structures that extend from the surface of eukaryotic cells, aiding in movement and sensory functions. Cilia are short and numerous, beating in a coordinated fashion to move fluids or propel the cell, while flagella are longer and usually occur singly or in pairs, providing propulsion through a whip-like motion. Both structures share a common "9+2" arrangement of microtubules, which is essential for their movement.

Answer 95

The cell wall is a rigid outer layer that provides structural support and protection to the cells of plants, fungi, bacteria, and some protists. Composed primarily of cellulose in plants, chitin in fungi, and peptidoglycan in bacteria, the cell wall helps maintain cell shape and prevents excessive water uptake. Additionally, it plays a role in regulating interactions with the environment and neighboring cells.

Answer 96

Plasmodesmata are microscopic channels that traverse the cell walls of plant cells, allowing for direct communication and transport of materials between neighboring cells. These structures facilitate the exchange of ions, nutrients, and signaling molecules, enabling coordinated responses and metabolic activities within plant tissues. By connecting the cytoplasm of adjacent cells, plasmodesmata play a crucial role in maintaining tissue integrity and function.

Answer 97

Tight junctions are specialized connections between adjacent epithelial cells that create a barrier to prevent the passage of substances between the cells. They seal the space between cells, ensuring that materials must pass through the cells rather than between them, which helps maintain distinct environments on either side of the epithelium. Tight junctions play a critical role in regulating permeability, protecting tissues, and contributing to the overall function of epithelial barriers in organs like the intestines and the blood-brain barrier.

Answer 98

Tight junctions are specialized connections between adjacent epithelial cells that create a barrier to prevent the passage of substances between the cells. They seal the space between cells, ensuring that materials must pass through the cells rather than between them, which helps maintain distinct environments on either side of the epithelium. Tight junctions play a critical role in regulating permeability, protecting tissues, and contributing to the overall function of epithelial barriers in organs like the intestines and the blood-brain barrier.

Answer 99

Desmosomes are specialized cell junctions that provide strong adhesion between adjacent cells, particularly in tissues subjected to mechanical stress, such as skin and cardiac muscle. They consist of protein structures that anchor the cytoskeleton of one cell to that of another, creating a resilient network that helps maintain tissue integrity. Desmosomes play a crucial role in resisting stretching and tearing, ensuring that cells remain connected under physical strain.

Answer 100

The pulse-chase experiment is a technique used in molecular biology to study cellular processes, particularly protein synthesis and transport. In this experiment, cells are first exposed to a "pulse" of labeled precursors (such as amino acids or nucleotides) for a short period, allowing researchers to track newly synthesized molecules. After the pulse, a "chase" phase begins where the labeled precursors are replaced with non-labeled ones, allowing scientists to observe how the labeled molecules move through the cell over time and how long they persist in various cellular compartments. This method provides insights into cellular dynamics, protein localization, and turnover rates.

Answer 101

Motor proteins are specialized proteins that convert chemical energy from ATP hydrolysis into mechanical work, facilitating movement within cells. They play essential roles in various cellular processes, such as muscle contraction, intracellular transport of organelles and vesicles, and cell division. Key types of motor proteins include myosin, which interacts with actin filaments for muscle movement; kinesin and dynein, which move along microtubules to transport cellular cargo; and they are crucial for maintaining cellular organization and function.

Answer 102

Hormones are chemical messengers produced by glands in the endocrine system that regulate various physiological processes in the body. They are released into the bloodstream and travel to target organs or tissues, where they elicit specific responses, such as regulating metabolism, growth, mood, and reproductive functions. Hormones play crucial roles in maintaining homeostasis and coordinating complex bodily functions across different systems.

Answer 103

Carbohydrates serve several essential functions in living organisms: 1. **Energy Source**: Carbohydrates are a primary source of energy for cells, providing quick fuel through simple sugars like glucose. 2. **Structural Support**: They contribute to the structure of cells and tissues, such as cellulose in plant cell walls and chitin in fungal cell walls. 3. **Cell Signaling**: Carbohydrates play a role in cell recognition and signaling, often found on the surface of cells as glycoproteins and glycolipids, aiding in immune responses and cell communication. 4. **Storage**: Carbohydrates like glycogen in animals and starch in plants serve as energy reserves that can be mobilized when needed. 5. **Hydration**: They help maintain hydration in the body, as carbohydrates can attract and hold water. Overall, carbohydrates are vital for energy, structure, and cellular communication.

Answer 104

Carbohydrates and fats are excellent sources of energy for several reasons: 1. **High Energy Density**: Both carbohydrates and fats contain a high number of calories per gram. Fats provide about 9 calories per gram, while carbohydrates provide about 4 calories per gram, making them efficient energy sources. 2. **Chemical Structure**: Their chemical bonds store significant amounts of energy. When metabolized, the breakdown of these bonds releases energy that cells can use for various functions. 3. **Versatile Metabolism**: Carbohydrates can be quickly converted into glucose, providing immediate energy, while fats are utilized for sustained energy during prolonged activities or fasting. 4. **Storage Efficiency**: Both are stored in the body in forms that are easily accessible. Carbohydrates are stored as glycogen in the liver and muscles, while fats are stored in adipose tissue, allowing the body to tap into these reserves when needed. Together, carbohydrates and fats play crucial roles in energy metabolism and support various bodily functions and activities.

Answer 105

Cellulose and chitin derive their tough structural qualities from their unique chemical structures and the way their molecules interact: 1. **Molecular Structure**: - **Cellulose** is composed of long chains of glucose molecules linked by β-1,4-glycosidic bonds. This arrangement creates straight, rigid fibers that can pack closely together. - **Chitin** is similar to cellulose but has N-acetylglucosamine units instead of glucose. This structural variation also leads to strong, long chains that provide rigidity. 2. **Hydrogen Bonding**: Both cellulose and chitin molecules form extensive hydrogen bonds between adjacent chains, resulting in strong intermolecular interactions. This bonding enhances their strength and stability, contributing to their toughness. 3. **Crystalline Structure**: In both materials, the arrangement of the chains leads to a crystalline structure, which increases resistance to mechanical stress. The organized structure makes it difficult for enzymes and other substances to break them down. These features make cellulose and chitin effective at providing structural support in plants and fungi, respectively.

Answer 106

Cell membranes are composed of several key molecules, each contributing to the membrane's structure and function. The main components include: 1. **Phospholipids**: - **Structure**: Composed of a hydrophilic (water-attracting) "head" and two hydrophobic (water-repelling) "tails." - **Properties**: They form a bilayer, with heads facing outward towards the aqueous environment and tails facing inward, creating a barrier that separates the cell from its surroundings. This amphipathic nature allows for membrane fluidity and flexibility. 2. **Proteins**: - **Types**: Integral (or membrane) proteins that span the membrane and peripheral proteins that are attached to the surface. - **Properties**: Integral proteins can function as channels or transporters for substances, while peripheral proteins are often involved in signaling or maintaining the cell’s shape. They contribute to selective permeability and communication. 3. **Cholesterol**: - **Structure**: A sterol molecule embedded within the phospholipid bilayer. - **Properties**: Cholesterol helps maintain membrane fluidity, providing stability in varying temperatures. It prevents the fatty acid chains from packing too closely, which can help keep the membrane flexible. 4. **Carbohydrates**: - **Structure**: Often attached to proteins (glycoproteins) or lipids (glycolipids) on the extracellular surface. - **Properties**: Carbohydrates play critical roles in cell recognition, signaling, and adhesion. They form protective layers and help in cell-to-cell communication. Together, these molecules create a dynamic and versatile membrane that regulates the entry and exit of substances, facilitates communication, and maintains the integrity of the cell.

Answer 107

Membrane proteins serve several essential functions, including transport of ions and nutrients across the membrane, and enzymatic activity that catalyzes biochemical reactions. They play a crucial role in signal transduction by binding to ligands and initiating cellular responses. Additionally, glycoproteins and glycolipids are involved in cell recognition and intercellular adhesion, maintaining tissue structure. Lastly, some membrane proteins anchor to the cytoskeleton, providing structural support and aiding in cell shape and movement.

Answer 108

The ability of hydrophobic and hydrophilic molecules to pass through the cell membrane differs due to the structure of the phospholipid bilayer. Hydrophobic molecules, such as lipids and nonpolar gases, can easily dissolve in the lipid environment and pass through without assistance. In contrast, hydrophilic molecules, like ions and polar substances, cannot cross the bilayer easily and often require specific transport proteins or channels. This selective permeability allows cells to regulate their internal environment effectively, facilitating the entry of essential nutrients while excluding harmful substances.

Answer 109

To passively transport a molecule that doesn’t easily cross the membrane, cells can utilize facilitated diffusion. This process involves specific transport proteins, such as channel proteins or carrier proteins, that assist in moving the molecule across the membrane without requiring energy. 1. **Channel Proteins**: These create hydrophilic pathways through which ions or polar molecules can pass directly, allowing for selective movement based on size and charge. 2. **Carrier Proteins**: These bind to the molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side, enabling transport without the need for ATP. Facilitated diffusion allows for the movement of substances along their concentration gradient, making it an efficient way to transport molecules that cannot freely diffuse through the lipid bilayer.

Answer 110

Active transport is required when molecules need to be moved against their concentration gradient, meaning from an area of lower concentration to an area of higher concentration. This process is essential in several scenarios: 1. **Nutrient Uptake**: Cells often need to absorb essential nutrients (like glucose or amino acids) from the surrounding environment where their concentration is lower. 2. **Ion Regulation**: Maintaining ion gradients (such as sodium, potassium, and calcium) is crucial for processes like nerve impulse transmission and muscle contraction, which requires transporting ions against their gradients. 3. **Cell Volume Regulation**: Active transport helps control the osmotic balance of the cell, preventing excessive swelling or shrinking by moving ions and solutes as needed. 4. **Removal of Waste**: Cells may need to expel waste products or toxins that have accumulated inside, requiring energy to move these substances out against their concentration gradients. In all these cases, active transport relies on the energy provided by ATP or other energy sources to drive the movement of molecules.

Answer 111

Prokaryotes and eukaryotes differ in several fundamental ways: 1. **Cell Structure**: - **Prokaryotes**: Have a simple cell structure without a nucleus; their genetic material (DNA) is located in a nucleoid region. They lack membrane-bound organelles. - **Eukaryotes**: Have a complex cell structure with a true nucleus that encloses their DNA and various membrane-bound organelles (e.g., mitochondria, endoplasmic reticulum). 2. **Size**: - **Prokaryotes**: Generally smaller (0.1 to 5 micrometers) and simpler in design. - **Eukaryotes**: Typically larger (10 to 100 micrometers) with more complex structures. 3. **Reproduction**: - **Prokaryotes**: Primarily reproduce asexually through binary fission, a simpler process. - **Eukaryotes**: Can reproduce both asexually (e.g., mitosis) and sexually (e.g., meiosis), allowing for greater genetic diversity. 4. **Genetic Material**: - **Prokaryotes**: Usually have a single, circular DNA molecule that is not associated with histones. - **Eukaryotes**: Have multiple linear DNA molecules organized into chromosomes and associated with histones, which help in packaging and regulating gene expression.

Answer 112

Compartmentalization in cells enhances efficiency by allowing multiple biochemical processes to occur simultaneously without interference. It enables specialization of organelles, creating unique environments optimal for specific functions, such as energy production in mitochondria. Additionally, it regulates metabolic pathways by controlling substrate and enzyme availability, preventing unwanted reactions. Lastly, compartmentalization protects sensitive cellular processes from potentially harmful substances in the cytoplasm, ensuring overall cellular integrity and function.

Answer 113

The ability of a protein to enter or exit the nucleus is primarily dictated by specific signals it contains, such as nuclear localization signals (NLS) for entry and nuclear export signals (NES) for exit. Nuclear transport receptors, like importins and exportins, recognize these signals and facilitate the transport of proteins through the nuclear pore complex. The nuclear pore complex itself acts as a selective barrier, regulating the passage of molecules based on size and the presence of these signals. Additionally, post-translational modifications can influence a protein's localization by altering its interaction with transport receptors or its conformation.

Answer 114

The extracellular excretion of a protein begins with its synthesis in the endoplasmic reticulum (ER), where it is folded and modified. The protein is then transported to the Golgi apparatus for further processing and sorting. After processing, it is packaged into secretory vesicles that bud off from the Golgi. These vesicles travel to the plasma membrane, fuse with it, and release the protein into the extracellular space through exocytosis.

Answer 115

The Golgi apparatus delivers proteins to the appropriate location by using specific sorting signals present in the proteins. As proteins pass through the Golgi, they undergo modifications that help determine their final destination, such as glycosylation or phosphorylation. The Golgi then packages these proteins into vesicles that contain specific tags or markers for their intended location, whether for secretion, incorporation into the membrane, or delivery to lysosomes. These vesicles transport the proteins to their designated sites within the cell or outside of it, ensuring proper cellular function.

Answer 116

Microtubules facilitate vesicle transport through their role as tracks for motor proteins. Here’s how it works: 1. **Structural Framework**: Microtubules form a network throughout the cell, providing a structural framework that supports the movement of vesicles. 2. **Motor Proteins**: Motor proteins, such as kinesin and dynein, attach to the vesicles and move along the microtubules. Kinesin typically transports vesicles toward the plus end (cell periphery), while dynein moves them toward the minus end (cell center). 3. **Energy Dependency**: The movement of motor proteins along microtubules is powered by ATP hydrolysis, allowing for active transport of vesicles. 4. **Directional Transport**: This system ensures that vesicles are accurately and efficiently delivered to their target destinations within the cell, facilitating processes such as secretion, endocytosis, and organelle communication.

Answer 117

Cell-cell adhesion serves several important purposes: 1. **Tissue Integrity**: Cell-cell adhesion helps maintain the structural integrity of tissues by holding cells together. This is accomplished through adhesion molecules, such as cadherins, that link the cytoskeletons of adjacent cells and form strong connections. 2. **Cell Communication**: Adhesion facilitates communication between cells, allowing for the exchange of signals and molecules. This is achieved through gap junctions, which are specialized connections that permit direct transfer of ions and small signaling molecules between neighboring cells. 3. **Development and Morphogenesis**: During development, cell-cell adhesion is crucial for guiding cells to their proper locations and forming organized structures. This is accomplished through various signaling pathways activated by adhesion molecules, such as integrins and selectins, that influence cell behavior, migration, and differentiation. These mechanisms enable cells to work together effectively, ensuring proper function and organization within tissues.

Answer 118

Feedback inhibition is a regulatory mechanism in biological systems where the end product of a metabolic pathway inhibits an enzyme involved in its production. This process prevents the overproduction of the product, helping to maintain homeostasis within the cell. By modulating enzyme activity, feedback inhibition allows cells to respond efficiently to changes in their environment and resource availability.

Answer 119

Reduction-oxidation reactions, commonly known as redox reactions, involve the transfer of electrons between molecules. In these reactions, one substance undergoes oxidation (loses electrons) while another undergoes reduction (gains electrons). This electron transfer is crucial for various biological processes, including cellular respiration and photosynthesis, as it helps to release and store energy.

Answer 120

Adenosine triphosphate (ATP) is a nucleotide that serves as the primary energy carrier in cells. It consists of adenine, ribose (a sugar), and three phosphate groups. ATP stores energy in the high-energy bonds between its phosphate groups, which can be released to power various cellular processes, such as muscle contraction, protein synthesis, and cell signaling. When ATP is hydrolyzed to adenosine diphosphate (ADP) and inorganic phosphate (Pi), energy is released for use in biological reactions.

Answer 121

NADH (nicotinamide adenine dinucleotide) is a coenzyme that plays a crucial role in cellular metabolism, particularly in redox reactions. It acts as an electron carrier, transporting electrons from one reaction to another, especially during cellular respiration and fermentation. NADH is generated during glycolysis, the citric acid cycle, and other metabolic pathways, and it ultimately contributes to the production of ATP in the electron transport chain.

Answer 122

FAD2, or flavin adenine dinucleotide (FAD) in its reduced form, is a coenzyme involved in various biological redox reactions. It functions similarly to NADH by carrying electrons, but it can accept two electrons and two protons, making it essential for processes like the citric acid cycle and fatty acid oxidation. FAD is crucial for the activity of certain enzymes, including flavoproteins, which play key roles in energy production and metabolic regulation.

Answer 123

Electron acceptors are molecules that receive electrons during redox reactions. They play a crucial role in various metabolic processes, including cellular respiration and fermentation. Common electron acceptors include oxygen (in aerobic respiration), nitrate, sulfate, and carbon dioxide (in anaerobic processes). The transfer of electrons to these acceptors helps drive energy production and maintain the flow of electrons through metabolic pathways.

Answer 124

Cellular respiration is a biochemical process through which cells convert glucose and oxygen into energy, primarily in the form of adenosine triphosphate (ATP). It typically occurs in three main stages: glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation (electron transport chain). In glycolysis, glucose is broken down into pyruvate, which enters the citric acid cycle, producing NADH and FADH₂. These electron carriers then feed electrons into the electron transport chain, where oxygen serves as the final electron acceptor, ultimately generating a large amount of ATP and water as byproducts. C6H12O6 +6 O2 ——>6 CO2+ 6 H2O

Answer 125

Glycolysis is the first step in cellular respiration, occurring in the cytoplasm of cells, where one molecule of glucose (C₆H₁₂O₆) is broken down into two molecules of pyruvate. This process involves a series of ten enzymatic reactions and can be divided into two phases: the energy investment phase, where ATP is consumed to activate glucose, and the energy payoff phase, where ATP and NADH are produced. The net gain from glycolysis is two ATP molecules and two NADH molecules per glucose molecule, and it serves as a crucial pathway for both aerobic and anaerobic metabolism.

Answer 126

Pyruvate is a key intermediate in cellular metabolism, formed at the end of glycolysis when glucose is broken down. Each molecule of glucose produces two molecules of pyruvate, which can then be further processed depending on the availability of oxygen. In aerobic conditions, pyruvate is transported into the mitochondria and converted into acetyl-CoA, entering the citric acid cycle. In anaerobic conditions, it can be converted into lactate (in animals) or ethanol and carbon dioxide (in yeast and some bacteria). Pyruvate thus plays a critical role in linking glycolysis to both aerobic and anaerobic pathways.

Answer 127

The Krebs cycle, or citric acid cycle, is a series of enzymatic reactions that occur in the mitochondria, converting acetyl-CoA into carbon dioxide while generating energy-rich electron carriers like NADH and FADH₂. Each turn of the cycle produces one ATP (or GTP) and releases carbon dioxide as a waste product. Since each glucose molecule generates two acetyl-CoA, the cycle turns twice for every glucose molecule processed, playing a crucial role in cellular respiration and energy production.

Answer 128

The mitochondrial matrix is the innermost compartment of mitochondria, surrounded by the inner mitochondrial membrane. It contains enzymes for the citric acid cycle (Krebs cycle), as well as mitochondrial DNA, ribosomes, and various metabolites. The matrix plays a crucial role in energy production by facilitating the breakdown of acetyl-CoA and the generation of electron carriers, which are essential for ATP synthesis in the electron transport chain.

Answer 129

Mitochondrial cristae are the inner membrane folds of mitochondria, extending into the mitochondrial matrix. These folds increase the surface area available for biochemical reactions, particularly those involved in the electron transport chain and ATP synthesis. The structure of cristae is crucial for efficient energy production, as they house the proteins and enzymes necessary for oxidative phosphorylation.

Answer 130

The electron transport chain (ETC) is a series of protein complexes located in the inner mitochondrial membrane that play a key role in cellular respiration. During this process, electrons from NADH and FADH₂ are transferred through these complexes, releasing energy that is used to pump protons (H⁺ ions) into the intermembrane space, creating a proton gradient. This gradient drives the synthesis of ATP as protons flow back into the matrix through ATP synthase, while oxygen serves as the final electron acceptor, forming water as a byproduct.

Answer 131

Complex I, also known as NADH:ubiquinone oxidoreductase, is the first protein complex in the electron transport chain. It catalyzes the transfer of electrons from NADH to ubiquinone (coenzyme Q), facilitating the conversion of NADH to NAD⁺. As electrons move through Complex I, the complex pumps protons (H⁺ ions) from the mitochondrial matrix into the intermembrane space, contributing to the proton gradient essential for ATP synthesis in oxidative phosphorylation.

Answer 132

Complex II, also known as succinate dehydrogenase, is the second protein complex in the electron transport chain. It catalyzes the oxidation of succinate to fumarate in the citric acid cycle, transferring electrons to ubiquinone (coenzyme Q), which is then reduced to ubiquinol. Unlike Complex I, Complex II does not pump protons across the membrane, but it plays a crucial role in connecting the citric acid cycle to the electron transport chain, contributing to the overall flow of electrons and energy production.

Answer 133

Complex III, also known as cytochrome bc₁ complex, is the third protein complex in the electron transport chain. It facilitates the transfer of electrons from ubiquinol (reduced coenzyme Q) to cytochrome c while simultaneously pumping protons (H⁺ ions) from the mitochondrial matrix into the intermembrane space, further contributing to the proton gradient. This complex plays a vital role in the overall process of oxidative phosphorylation, helping to generate ATP as protons flow back through ATP synthase.

Answer 134

Complex IV, also known as cytochrome c oxidase, is the final protein complex in the electron transport chain. It catalyzes the transfer of electrons from cytochrome c to molecular oxygen, reducing it to water. During this process, Complex IV also pumps protons (H⁺ ions) into the intermembrane space, enhancing the proton gradient that drives ATP synthesis via ATP synthase. This complex is essential for aerobic respiration, as it utilizes oxygen as the final electron acceptor.

Answer 135

ATP synthase is a large enzyme complex located in the inner mitochondrial membrane that synthesizes adenosine triphosphate (ATP). It utilizes the proton gradient created by the electron transport chain, where protons flow back into the mitochondrial matrix through the enzyme. As protons pass through ATP synthase, the energy from this movement drives the conversion of adenosine diphosphate (ADP) and inorganic phosphate (Pi) into ATP, making it a crucial component of oxidative phosphorylation and energy production in cells.

Answer 136

Oxidative phosphorylation is the final stage of cellular respiration, occurring in the inner mitochondrial membrane. It involves the transfer of electrons through the electron transport chain, resulting in the pumping of protons (H⁺ ions) into the intermembrane space and creating a proton gradient. This gradient drives protons back into the mitochondrial matrix through ATP synthase, which synthesizes ATP from ADP and inorganic phosphate (Pi). Oxygen acts as the final electron acceptor, forming water as a byproduct, making oxidative phosphorylation essential for efficient ATP production in aerobic organisms.

Answer 137

Fermentation is an anaerobic metabolic process that converts sugars into energy in the absence of oxygen. During fermentation, glucose is partially oxidized, resulting in the production of ATP along with byproducts such as ethanol and carbon dioxide in alcoholic fermentation, or lactate in lactic acid fermentation. This process allows cells to regenerate NAD⁺, enabling glycolysis to continue and providing a rapid source of energy when oxygen is limited.

Answer 138

Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy, using sunlight to synthesize glucose from carbon dioxide and water. It occurs primarily in the chloroplasts, where chlorophyll captures light energy, driving the light-dependent reactions that generate ATP and NADPH. These energy carriers are then utilized in the Calvin cycle to convert carbon dioxide into glucose, releasing oxygen as a byproduct. 6CO2 + 6H2O + light energy → C6H12O6 + 6O2

Answer 139

NADPH (nicotinamide adenine dinucleotide phosphate) is a coenzyme that serves as a crucial electron donor in various biochemical reactions, particularly in anabolic processes. It is produced during the light-dependent reactions of photosynthesis and is used primarily in the Calvin cycle to help convert carbon dioxide into glucose. NADPH plays a vital role in biosynthetic reactions, such as fatty acid and nucleotide synthesis, and also helps protect cells from oxidative stress by regenerating antioxidants.

Answer 140

Chloroplasts are specialized organelles found in the cells of green plants and algae, responsible for photosynthesis. They contain chlorophyll, the green pigment that captures light energy, and have a double membrane structure. Inside, chloroplasts have thylakoids arranged in stacks called grana, where light-dependent reactions occur, and a fluid-filled space called the stroma, where the Calvin cycle takes place, converting carbon dioxide into glucose.

Answer 141

Thylakoids are membrane-bound structures within chloroplasts that are the site of the light-dependent reactions of photosynthesis. They are arranged in stacks known as grana, which increase the surface area for light absorption. The thylakoid membrane contains chlorophyll and other pigments that capture light energy, leading to the production of ATP and NADPH, which are then used in the Calvin cycle to synthesize glucose.

Answer 142

The stroma is the fluid-filled space within chloroplasts that surrounds the thylakoids. It plays a crucial role in the process of photosynthesis, particularly in the Calvin cycle, where carbon dioxide is converted into glucose using ATP and NADPH generated in the light-dependent reactions. The stroma contains enzymes, DNA, ribosomes, and various metabolites, supporting the overall metabolic functions of the chloroplast.

Answer 143

The lumen refers to the interior space of thylakoids within chloroplasts. It plays a critical role in photosynthesis, particularly in the light-dependent reactions, where protons (H⁺ ions) are pumped into the lumen, creating a proton gradient. This gradient is then used by ATP synthase to produce ATP as protons flow back into the stroma during the process of oxidative phosphorylation.

Answer 144

Chlorophyll is a green pigment found in the chloroplasts of plants, algae, and cyanobacteria, essential for photosynthesis. It absorbs light energy, primarily in the blue and red wavelengths, and reflects green light, giving plants their characteristic color. Chlorophyll plays a critical role in converting light energy into chemical energy by facilitating the transfer of absorbed energy to the photosynthetic electron transport chain.

Answer 145

A photon is a fundamental particle of light and electromagnetic radiation, characterized as a discrete unit of energy. It has no mass and travels at the speed of light, carrying energy that is proportional to its frequency. In photosynthesis, photons are absorbed by pigments like chlorophyll, providing the energy necessary to drive the light-dependent reactions, which ultimately produce ATP and NADPH for the synthesis of glucose.

Answer 146

Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. In this process, a material absorbs photons and then quickly re-emits them, typically at a longer wavelength (lower energy). Fluorescence is commonly observed in certain pigments, such as chlorophyll, which can emit light when excited by sunlight, playing a role in processes like photosynthesis and allowing scientists to study cellular structures and functions through fluorescent microscopy.

Answer 147

The antenna complex, also known as a light-harvesting complex, is a structure in photosynthetic organisms that consists of pigments and proteins. Its primary function is to capture and absorb light energy from the sun and transfer it efficiently to the reaction center of a photosystem. The antenna complex contains various pigments, such as chlorophyll a, chlorophyll b, and carotenoids, which work together to maximize light absorption across different wavelengths, enhancing the overall efficiency of photosynthesis.

Answer 148

The reaction center is a key component of photosystems in photosynthesis, where light energy is converted into chemical energy. It consists of a specialized pair of chlorophyll molecules and associated proteins that facilitate the transfer of excited electrons. When light is absorbed by the antenna complex, energy is funneled to the reaction center, leading to the excitation of electrons that are then transferred to the electron transport chain, initiating the process of energy conversion.

Answer 149

The light-dependent reactions of photosynthesis occur in the thylakoid membranes of chloroplasts and require sunlight to take place. When light is absorbed by chlorophyll and other pigments in the antenna complexes, it excites electrons, which are then transferred through a series of protein complexes in the electron transport chain. This process generates ATP and NADPH while splitting water molecules to release oxygen as a byproduct.

Answer 150

The light-independent reactions, also known as the Calvin cycle, occur in the stroma of chloroplasts and do not require direct light to take place. During this process, ATP and NADPH produced in the light-dependent reactions are used to convert carbon dioxide into glucose. The cycle involves three main phases: carbon fixation, reduction, and regeneration of ribulose bisphosphate (RuBP), ultimately leading to the synthesis of carbohydrates that serve as energy sources for the plant.

Answer 151

Photosystem I (PSI) is a protein-pigment complex involved in the light-dependent reactions of photosynthesis, primarily located in the thylakoid membrane of chloroplasts. It contains a core complex with a reaction center that includes chlorophyll a, which absorbs light energy and excites electrons. These high-energy electrons are ultimately transferred to NADP⁺, reducing it to NADPH, which is then used in the Calvin cycle to synthesize glucose. PSI operates after Photosystem II, contributing to the overall process of energy conversion in photosynthesis.

Answer 152

Photosystem II (PSII) is a crucial protein-pigment complex in the light-dependent reactions of photosynthesis, located in the thylakoid membrane of chloroplasts. It absorbs light energy, primarily in the blue and red wavelengths, and uses that energy to excite electrons from water molecules, facilitating the splitting of water (photolysis) into oxygen, protons, and electrons. The excited electrons are then transferred through the electron transport chain, contributing to the production of ATP and NADPH, which are essential for the subsequent light-independent reactions (Calvin cycle).

Answer 153

Photophosphorylation is the process of adding a phosphate group to adenosine diphosphate (ADP) to form adenosine triphosphate (ATP) using light energy, primarily during the light-dependent reactions of photosynthesis. This process occurs in the thylakoid membranes of chloroplasts, where absorbed light energy drives the electron transport chain, creating a proton gradient across the thylakoid membrane. The flow of protons back into the stroma through ATP synthase utilizes this gradient to generate ATP, which is then used in the Calvin cycle to synthesize glucose.

Answer 154

The Z scheme is a model that describes the flow of electrons during the light-dependent reactions of photosynthesis in plants. It illustrates how electrons are excited by light in both Photosystem II (PSII) and Photosystem I (PSI), creating a series of energy transitions. In this process, water is split in PSII, releasing oxygen and providing electrons that travel through the electron transport chain, ultimately reaching PSI, where they are re-excited by light and transferred to NADP⁺, forming NADPH. The Z scheme highlights the interconnectedness of the two photosystems and their roles in producing ATP and NADPH for the Calvin cycle.

Answer 155

The Calvin cycle, occurring in the stroma of chloroplasts, is a series of light-independent reactions that convert carbon dioxide into glucose using ATP and NADPH produced during the light-dependent reactions. It consists of three main phases: carbon fixation, where CO₂ is combined with ribulose bisphosphate (RuBP); reduction, which transforms 3-phosphoglycerate into glyceraldehyde-3-phosphate; and regeneration, which restores RuBP to enable the cycle to continue. This process ultimately synthesizes carbohydrates that provide energy for the plant.

Answer 156

Ribulose bisphosphate carboxylase/oxygenase, commonly known as rubisco, is an essential enzyme in the Calvin cycle of photosynthesis. It catalyzes the reaction of carbon dioxide with ribulose bisphosphate (RuBP) to form 3-phosphoglycerate, initiating the process of carbon fixation. Rubisco is the most abundant protein on Earth and plays a critical role in converting inorganic carbon into organic compounds, although it is also known for its tendency to react with oxygen, leading to a process called photorespiration under certain conditions.

Answer 157

Stomata are small openings on the surfaces of leaves and stems that facilitate gas exchange in plants. They allow carbon dioxide to enter for photosynthesis and oxygen to exit as a byproduct, while also regulating water vapor loss through transpiration. Each stoma is surrounded by a pair of guard cells that control its opening and closing, helping the plant respond to environmental conditions such as light, humidity, and water availability.

Answer 158

Cells specialize for particular functions through a process called differentiation, which involves the selective expression of genes in response to internal and external signals. During development, stem cells can give rise to various cell types by activating specific sets of genes that determine their structure and function. Environmental factors, such as signaling molecules, hormones, and extracellular matrix interactions, also influence differentiation, allowing cells to adapt to their roles in tissues and organs, such as muscle cells for contraction or neurons for transmitting signals.

Answer 159

C6H12O6 +6 O2 ——>6 CO2+ 6 H2O

Answer 160

In cellular respiration, glucose is oxidized, meaning it loses electrons during its breakdown, while oxygen is reduced, meaning it gains electrons. Specifically, during glycolysis and the citric acid cycle, glucose is converted into carbon dioxide, releasing electrons that are captured by electron carriers like NAD⁺ and FAD, which are reduced to NADH and FADH₂, respectively. In the electron transport chain, oxygen acts as the final electron acceptor, combining with the electrons and protons to form water, completing the redox process.

Answer 161

In glycolysis, the main reactants are one molecule of glucose, two NAD⁺, and two ATP. The process results in the production of two molecules of pyruvate, four ATP (net gain of two ATP, since two are consumed), and two NADH. Glycolysis occurs in the cytoplasm and is the first step in both aerobic and anaerobic respiration.

Answer 162

In the Krebs cycle, also known as the citric acid cycle, the main reactants are acetyl-CoA (derived from pyruvate), water, and oxaloacetate. The cycle produces several products: for each acetyl-CoA that enters, it generates two carbon dioxide molecules, three NADH, one FADH₂, and one ATP (or GTP). The cycle also regenerates oxaloacetate, allowing the process to continue for each new acetyl-CoA that enters.

Answer 163

In the electron transport chain (ETC), the main reactants are NADH and FADH₂ (which donate electrons), along with oxygen as the final electron acceptor. The primary products of the ETC are ATP, generated through oxidative phosphorylation, and water, formed when electrons combine with oxygen and protons. Additionally, the ETC facilitates the pumping of protons (H⁺ ions) across the inner mitochondrial membrane, creating a proton gradient that drives ATP synthesis via ATP synthase.

Answer 164

In cellular respiration, electrons primarily come from the oxidation of glucose. During glycolysis and the Krebs cycle, glucose is broken down, and high-energy electrons are transferred to electron carriers, specifically NAD⁺ and FAD, forming NADH and FADH₂. These electrons are then passed through the electron transport chain (ETC) in the inner mitochondrial membrane. They move through a series of protein complexes, losing energy at each step, which is used to pump protons across the membrane and create a proton gradient. Ultimately, the electrons end up being transferred to molecular oxygen, the final electron acceptor, forming water when they combine with protons.

Answer 165

n cellular respiration, the path of electrons can be traced as follows: Glycolysis: Location: Cytoplasm Process: Glucose is broken down into two molecules of pyruvate. During this process, electrons are transferred to NAD⁺, reducing it to NADH. Pyruvate Oxidation: Location: Mitochondrial matrix Process: Each pyruvate is converted to acetyl-CoA, producing more NADH from the oxidation of pyruvate. Krebs Cycle (Citric Acid Cycle): Location: Mitochondrial matrix Process: Acetyl-CoA enters the cycle, and through a series of reactions, electrons are transferred to NAD⁺ and FAD, forming more NADH and FADH₂. Carbon dioxide is released as a byproduct. Electron Transport Chain (ETC): Location: Inner mitochondrial membrane Process: NADH and FADH₂ donate their electrons to the ETC. The electrons move through a series of protein complexes (Complexes I, II, III, and IV), losing energy at each step, which is used to pump protons into the intermembrane space, creating a proton gradient. Final Electron Acceptors: Location: At Complex IV of the ETC Process: Electrons ultimately combine with molecular oxygen (O₂) and protons (H⁺) to form water (H₂O).

Answer 166

The processes dealing with electrons in cellular respiration are regulated through mechanisms such as allosteric regulation, where the binding of metabolites can activate or inhibit key enzymes, and feedback inhibition, where end products inhibit earlier steps in the pathway. Additionally, the availability of substrates, hormonal control, and oxygen levels can significantly influence the rates of glycolysis, the Krebs cycle, and the electron transport chain. These regulatory mechanisms ensure that cellular respiration efficiently meets the energy demands of the cell.

Answer 167

In the absence of an electron acceptor, such as oxygen, glucose processing is accomplished through anaerobic fermentation pathways. In this process, glycolysis still occurs, breaking down glucose into pyruvate, which is then converted into products like lactic acid (in animals) or ethanol and carbon dioxide (in yeast and some bacteria). This conversion regenerates NAD⁺ from NADH, allowing glycolysis to continue producing ATP, albeit at a lower yield compared to aerobic respiration. This anaerobic processing is necessary because cells require a continuous supply of NAD⁺ to sustain glycolysis and ATP production, especially in environments lacking oxygen. By utilizing fermentation, cells can maintain energy production even when aerobic respiration is not possible.

Answer 168

6CO2 + 6H2O + light energy → C6H12O6 + 6O2

Answer 169

In photosynthesis, water (H₂O) is oxidized, meaning it loses electrons during the light-dependent reactions. This oxidation process results in the splitting of water molecules, which releases oxygen (O₂) as a byproduct. The electrons released from water are used to help convert light energy into chemical energy, ultimately contributing to the formation of glucose during the Calvin cycle.

Answer 170

The light-dependent reactions of photosynthesis occur in the thylakoid membranes of chloroplasts. These reactions capture light energy and convert it into chemical energy in the form of ATP and NADPH, while also producing oxygen as a byproduct from the splitting of water molecules.

Answer 171

The light-independent reactions, also known as the Calvin cycle, occur in the stroma of chloroplasts. These reactions do not require light directly; instead, they use ATP and NADPH generated during the light-dependent reactions to convert carbon dioxide into glucose. The cycle involves carbon fixation, reduction of 3-phosphoglycerate, and regeneration of ribulose bisphosphate (RuBP), ultimately producing carbohydrates for the plant.

Answer 172

The electrons for Photosystem II (PSII) come from the oxidation of water (H₂O) molecules. During the light-dependent reactions of photosynthesis, when PSII absorbs light energy, it excites electrons from chlorophyll. To replace these excited electrons, water is split in a process known as photolysis, releasing oxygen as a byproduct and providing the necessary electrons for PSII to continue the process of capturing light energy and driving the electron transport chain.

Answer 173

The electrons for Photosystem I (PSI) primarily come from the electron transport chain that follows Photosystem II (PSII). After PSII absorbs light energy and excites electrons, these electrons travel through a series of protein complexes in the electron transport chain, losing energy along the way. Eventually, the electrons reach PSI, where they are re-excited by light absorbed by chlorophyll, allowing them to continue on to reduce NADP⁺ to NADPH, which is used in the Calvin cycle.

Answer 174

The Calvin cycle consists of three main phases: 1. **Carbon Fixation**: In this phase, carbon dioxide (CO₂) is incorporated into ribulose bisphosphate (RuBP) by the enzyme ribulose bisphosphate carboxylase/oxygenase (rubisco), resulting in a 6-carbon compound that quickly splits into two molecules of 3-phosphoglycerate (3-PGA). 2. **Reduction**: During this phase, ATP and NADPH produced in the light-dependent reactions are used to convert 3-PGA into glyceraldehyde-3-phosphate (G3P), a 3-carbon sugar. Some of the G3P molecules are used to regenerate RuBP, while others can be used to synthesize glucose and other carbohydrates. 3. **Regeneration of RuBP**: In this final phase, some of the G3P molecules undergo a series of reactions to regenerate ribulose bisphosphate (RuBP), allowing the cycle to continue. This phase also consumes ATP, completing the cycle. Together, these phases enable the conversion of carbon dioxide into organic compounds, ultimately leading to the production of glucose.

Answer 175

For Photosystem I (PSI), the main reactants are: 1. **Light energy**: Absorbed by chlorophyll and other pigments. 2. **Electrons**: Received from the electron transport chain, specifically from the re-excitation of electrons that were initially excited in Photosystem II. 3. **NADP⁺**: The final electron acceptor. The products of PSI are: 1. **NADPH**: Formed when the excited electrons reduce NADP⁺, providing reducing power for the Calvin cycle. 2. **ATP**: While not directly produced by PSI, the electron transport chain connected to PSI contributes to the creation of a proton gradient that drives ATP synthesis through ATP synthase. In summary, PSI captures light energy to produce NADPH, essential for the light-independent reactions (Calvin cycle).

Answer 176

For Photosystem II (PSII), the main reactants are: 1. **Light energy**: Absorbed to excite electrons. 2. **Water (H₂O)**: Used in the process of photolysis. The primary products of Photosystem II are: 1. **Oxygen (O₂)**: Released as a byproduct from the splitting of water. 2. **Electrons**: Energized electrons that move to the electron transport chain. 3. **ATP**: Produced indirectly through the proton gradient established by the electron transport chain. These products play crucial roles in the light-dependent reactions of photosynthesis, facilitating the conversion of light energy into chemical energy.

Answer 177

Reactants of the Calvin Cycle: 1. **Carbon dioxide (CO₂)**: Obtained from the atmosphere. 2. **ATP**: Provided by the light-dependent reactions. 3. **NADPH**: Also generated from the light-dependent reactions. Products of the Calvin Cycle: 1. **Glucose (C₆H₁₂O₆)**: A simple sugar produced for energy storage. 2. **ADP**: Released after ATP is used. 3. **NADP⁺**: Formed when NADPH is used, allowing it to return to the light-dependent reactions. The Calvin cycle utilizes these reactants to synthesize glucose while regenerating ADP and NADP⁺ for reuse in the light-dependent processes.

Answer 178

Rubisco, or ribulose bisphosphate carboxylase/oxygenase, is an enzyme that catalyzes the first major step of the Calvin cycle in photosynthesis. It facilitates the reaction between carbon dioxide (CO₂) and ribulose bisphosphate (RuBP), producing two molecules of 3-phosphoglycerate (3-PGA). This reaction is crucial because it initiates the process of carbon fixation, converting inorganic carbon into an organic form that can be used to synthesize glucose and other carbohydrates. As one of the most abundant enzymes on Earth, rubisco plays a vital role in supporting the energy needs of nearly all life forms by contributing to the primary production of organic matter in ecosystems.

Answer 179

Respiration and photosynthesis are complementary processes that involve energy transformation; photosynthesis converts light energy into chemical energy in the form of glucose, while respiration breaks down glucose to release energy as ATP. Both processes feature metabolic pathways that include electron transport chains but differ in their functions, reactants, and products. Photosynthesis occurs in plants, using carbon dioxide and water to produce glucose and oxygen, whereas respiration occurs in all living organisms, using glucose and oxygen to produce carbon dioxide and water. Together, they create a cycle that sustains life on Earth by balancing oxygen and carbon dioxide levels in the atmosphere and facilitating energy flow through ecosystems.

Answer 180

Selective permeability Barrier to the outside

Answer 181

Animals, Plants, and Bacteria

Answer 182

Contians DNA

Answer 183

Animals and Plants

Answer 184

Protein Synthesis

Answer 185

Plants, Proteins, and Bacteria

Answer 186

Lipid Synthesis

Answer 187

Animals and Plants

Answer 188

Protein manufacturer and transport

Answer 189

Plants and Animals

Answer 190

Manufacturing, Shipping, and Packing center

Answer 191

Plants and Animals

Answer 192

Plants, Animals, Maybe some bacteria

Answer 193

Plans and Animals

Answer 194

Gathers free radicals, converts them to H2O2, then breaks them down

Answer 195

Plants and Animals

Answer 196

Cellular Respiration (energy)

Answer 197

Plants and Animals

Answer 198

Photosynthesis

Answer 199

Cell-Cell recognition and adhesion

Answer 200

Plants and Animals

Answer 201

Intercellular structure

Answer 202

Plants and Animals

Answer 203

Cell reproduction

Answer 204

Plants and Bacteria

Answer 205

Outer structure and protection

Answer 206

Describes packaging, synthesis, and use of proteins

Answer 207

Monosaccharide (m) Polysaccharide (p)

Answer 208

Immediate Energy Occasional Structure

Answer 209

Nucleotides (M) Nucleic Acids (P)

Answer 210

Information storage DNA RNA

Answer 211

Double helix Sugar is deoxyribose Bases are guanine, adenine, cytosine, and thymine

Answer 212

Single stranded Sugar is ribose Bases are guanine, adenine, cytosine, and uracil

Answer 213

Amino Acids (m) Polypeptide (p)

Answer 214

Enzymes Transportation Structure Hormones and cell communication

Answer 215

Fatty acids (m) Lipids (p)

Answer 216

Stored energy Insulation

Answer 217

Simple Diffusion: small, non polar molecules can cross membrane Facilitated Diffusion: naturally occus with channel Osmosis: movement of H2O from low to high concentration gradient

Answer 218

Requires energy input (ATP) Against concentration gradient

Answer 219

What is being manipulated

Answer 220

The meausred variable

Answer 221

No result for comparison

Answer 222

When there is a result for comparison

Answer 223

A hypothesis that states there will be no relationship

Answer 224

A hypothesis that states there will be a relationship

Answer 225

The higher the population size the lower the standard error

Answer 226

The probability of rejecting the null hypothesis and the study having no relationship.

Answer 227

More than 0.05 means you reject your null hypothesis Less than 0.05 means you fail to reject your null hypothesis

Answer 228

The rest is lost to heat: body temperature and sweating

Answer 229

There is no electron receptor so then fermentation can be used to regenerate NAD+ so that glycolysis can continue If there is no receptor, the fermentation occurs

Answer 230

ATP synthase is an enzyme that makes ATP, which cells use for energy. It works by using a flow of protons (tiny charged particles) across a membrane; as protons move back into the cell, ATP synthase uses that energy to turn ADP and a phosphate into ATP. This process helps produce the energy needed for various cellular activities.

Answer 231

They bind to Oxygen

Answer 232

Photosynthesis is the process of a plant taking Co2, H2O, and sunlight to produce glucose and 6 carbon chains Convert light energy to chemical energy

Answer 233

In the chlorplast?

Answer 234

The processes of cellular respiration are regulated by their products Sometimes the product will bind to What inhibits glycolysis? High ATP concentrations What inhibits the Kreb Cycle/Citric Acid Cycle High ATP, NADH Kreb is also accelerated by ADP, Acetyl-CoA, and NAD+

Answer 235

In the cytoplasm

Answer 236

ATP, Glucose

Answer 237

NADH, ATP, Pyruvate

Answer 238

In the mitochondrial matirx

Answer 239

Pyruvate (becomes oxidized and becomes Acetyl-CoA

Answer 240

Co2, NADH, FADH2, ATP

Answer 241

Inside the inner membranes of the mitochondria

Answer 242

NADH, FADH2, O2

Answer 243

Sunlight, Water, Carbon Dioxide

Answer 244

Mainly in the leaves, inside the chloroplasts which contain chloroplyll

Answer 245

Location: Thylaoid Membrane of Chloroplasts Process: Sunlight is absorbed by chlorophyll. Water molecules are split (photolysis) into oxygen, protons, and electrons. Energy from sunlight is used to convert ADP and NADP⁺ into energy carriers ATP and NADPH. Oxygen (O₂) is released as a byproduct. Outputs: ATP, NADPH, and O₂.

Answer 246

Location: Stroma of chloroplasts. Process: CO₂ is captured from the air and combined with a five-carbon sugar (ribulose bisphosphate, RuBP) to form a six-carbon compound. This compound quickly splits into two three-carbon molecules (3-phosphoglycerate, 3-PGA). Using ATP and NADPH from the light reactions, 3-PGA is converted into glyceraldehyde-3-phosphate (G3P), a three-carbon sugar. Some G3P molecules are used to regenerate RuBP, allowing the cycle to continue, while others are used to produce glucose and other carbohydrates. Outputs: Glucose (C₆H₁₂O₆) and other carbohydrates.

Answer 247

Provides energy and food for plants and all living orgnaisms. Reduces carbon dioxide levels in the atmosphere (climate change) Produces Oxygen, essential for all life on earth

Answer 248

4 protein complexes

Answer 249

It allows for the concntration gradient to be present and for pressure to build up so that the hydrogens can get pushed over to the ATP synthase protein.

Answer 250

Photosystem II

Answer 251

Fixation Reduction Regeneration

Answer 252

Co2 attaches to a 5 carbon sugar by rubisco forming a 6 carbon ocmpound that splits into 3 carbon molecules

Answer 253

ATP and NADPH convert the 2 3 carbon molecules to G3P (another 3 carbon molecule)

Answer 254

Some G3P go to form glucose and others are used to form rubisco

Answer 255

No electrons to build bonds, no glucose

Answer 256

No biomass. Carbons in the air are used to build the glucose.

Answer 257

Like a ruler to compare size of DNA fragments

Answer 258

The top is negatively charges while the bottom is postively charged

Answer 259

It runs to the positive charges in the bottom

Answer 260

Usually to the left of the ladder. Has no imput to prove the gel itself doens't have DNA in it. Should be blank.

Answer 261

The shorter DNA fragment is farther down while the longer DNa fragment is higher up.

Answer 262

Rearrange SE formula.

Answer 263

Standard Error of the Mean

Answer 264

All species have descended from a common ancestor

Answer 265

All organisms are made up of cells, and come from pre-existing cells

Answer 266

The basis to life

Answer 267

Degree of spread within a data set

Answer 268

Difference betweennhighest and lowest data points

Answer 269

The average distance between the data points and mean

Answer 270

Standard error in biology shows how much a sample's average might differ from the real average of the whole group. It helps researchers know if their results are reliable or if they might just be due to chance.

Answer 271

The probability of wrongly rejecting the null hpothesis if it is true.

Answer 272

Energy imput

Answer 273

They attach to a protein like a zipcode to directwhere they need to go in the cell

Answer 274

The lysosome

Answer 275

Storage, Transport

Answer 276

Break down toxic or destructive substances through oxidation reactions. Alcohol is oxidized in the peroxisome

Answer 277

Break down old or worn down things without a purpose

Answer 278

Powerhouse of the cell, produces energy, cellular respiration

Answer 279

Produces energy in photosynthesis?

Answer 280

Cell replication

Answer 281

There wouldn't be protein synthesis

Answer 282

The peroxisome is not functioning properly

Answer 283

Structure and protection in plant cells. Animlas don't ahve a cell wall.

Answer 284

Plant cells

Answer 285

Both plant and animal cells

Answer 286

Ahir like structures ot move an organelle

Answer 287

Cell to cell recognition and adhesion

Answer 288

Can seal cells together, act as channels, or connect the cytoplasms of cells

Answer 289

Channels for cell to cell communicaiton in plants

Answer 290

Prokaryotic

Answer 291

When you are losing electrons.

Answer 292

When you are gaining electrons.

Answer 293

They always come in a pair, one side of the equation performs one and then the other side doed the other

Answer 294

Oxidative reactions Lose an electron Reduction reactions Gain an electron

Answer 295

OXYGEN becomes (reduced) WATER GLUCOSE becomes (oxidized) CARBON DIOXIDE

Answer 296

Glucose and Oxygen

Answer 297

Carbon Dioxide, Water, and Energy

Answer 298

1. Glycolysis -> 6 carbon chains (glucose), 2 ATP, NAD+, ADP <- Pyruvate (2), 2 ATP, NADH Regulated by the products and the imput Occus in the Mitochondrial Matrix 2. Pyruvate Processing ->Pyruvate, CoA, NAD+ <-NADH, CO2, Acetyl-CoA, ATP Regualted by the imputs and the outputs Occurs in the Mitochondrial Matrix 3. Creb/Citric Acid Cycle ->Acetyl-CoA, H2O, NAD+, FAD, ADP <-CO2, CoA, NADH, ATP/GTP, FADH2 Regualted by the imputs and outputs Occurs in the Mitochondrial Matrix 4. Electron Transport Chain ->NADH, FADH2, ADP, O2 <-NAD+, FAD, ATP, H2O Regualted by the imputs and outputs Occurs in the Inner Membrane of the Mitochondrial Matrix

Answer 299

Plants and animals. All eukaryotes.

Answer 300

The Citric Acid Cycle. If the result is the opposite than the cell is lacking NADH

Answer 301

It recieves Oxygen. Oxygen gets oxidized to H2O

Answer 302

So the hydrogen ions can stay in the proton gradient without entering then cell and messing with intercellular things

Answer 303

Blocks complex 4 so electrons can not be picked up, so electrons cant be dropped off. Then the electron gradient runs out and NAD+ is stored insided fo the cell so that no energy can be stored or used.

Answer 304

Becomes carbon dioxide

Answer 305

Becomes water

Answer 306

The rpocess that occurs when we run out of oxygen. Everything gets shut down. Is not super productive, will not kepe us alive for very long.

Answer 307

Lactic Acid build up becuase fermentation occurs whne you excercise.

Answer 308

Carbon Dioxide, Water, Energy (light)

Answer 309

6 Carbon molecule (glucose), O2

Answer 310

Provides energy for the plant cell.

Answer 311

Light Reaction and Light Independent Reactions/Calvin Cycle

Answer 312

Plants, algae, certain bacteria

Answer 313

The only color that ins't absorbed

Answer 314

Best, Red or Violet Worst, Green YUCK

Answer 315

CO2, ATP, NADPH -> ADP, NADP+, Glucose

Answer 316

Rubisco, this is essential for fixing carbon in the carbon cycle.

Answer 317

To store the food for when there isn't light readily availible.

Answer 318

The air the plant is breathing becomes the physical structure.

Answer 319

It is used in and becomes Oxygen.

Test 1 Flashcards

(355 cards)