Final Review Flashcards
(117 cards)
1
Q
8 Characteristics of Living Things
A
Contain DNA
Grow & Develop
Respond to their environment (stimulus)
Reproduce (asexual & sexual)
Maintain stable internal environment (homeostasis)
Obtain and use material and energy (metabolism)
Made of cells
Evolve over time
2
Q
Atomic Structure
A
neutron (neutral charge) +proton (positive charge) in the middle
Electron (negative charge) on the outside
3
Q
Covalent Bonding
A
valence electrons are shared
4
Q
Ionic Bonding
A
Valence electrons are given/taken away until valence energy level is full.
Creates a positive ion and a negative ion.
5
Q
Properties of Water
A
polarity, high heat capacity, high heat of vaporization, and cohesive/adhesive behavior
Cohesive-> to itself
Adhesive-> to other materials
6
Q
Chemical Reactions
A
reactants-> products
7
Q
Activation Energy
A
the minimum amount of energy needed to initiate a chemical reaction
8
Q
Function of enzymes
A
act as catalysts in living organisms, significantly speeding up biochemical reactions without being consumed or permanently altered in the process
9
Q
Exergonic reactions
A
spontaneous
energy is released
10
Q
Endergonic reactions
A
non-spontaneous
energy is absorbed
11
Q
Polymer vs. Monomer
A
monomers are the small, repeating units that combine to form larger molecules called polymer
12
Q
Carbohydrates
A
Monomer: Monosaccharides
Polymer: Polysaccharides
13
Q
Lipids
A
Monomers: Glycerol and fatty acids
Polymer: fats, oils, waxes
14
Q
Proteins
A
Monomers: amino acids
Polymers: polypeptides
15
Q
Nucleic Acids
A
Monomers: nucleotides
Polymers: DNA and RNA
16
Q
Elements found in living things
A
carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur
17
Q
Nucleus
A
serves as the cell’s control center and houses the genetic material, DNA
18
Q
Cell membrane
A
a protective barrier and a regulator of substance movement in and out of the cell
19
Q
cell wall
A
only in plants
provide structural support, shape, and protection to the cell
20
Q
Ribosomes
A
the site of protein synthesis, also known as translation. They read the genetic code carried by messenger RNA (mRNA) and use it to assemble amino acids into proteins, which are essential for all cellular functions.
21
Q
mitochondria
A
generate energy in the form of ATP (adenosine triphosphate) through a process called cellular respiration
22
Q
Chloroplast
A
where photosynthesis takes place, the process by which plants convert light energy into chemical energy in the form of glucose
23
Q
chlorophyll
A
capture light energy and convert it into chemical energy during photosynthesis
24
Q
lysosomes
A
digestion and recycling of cellular waste. They contain a variety of enzymes that break down cellular debris, foreign particles, and worn-out cell components
25
Active Transport
movement against a gradient
requires energy
includes endocytosis, exocytosis, protein pumps
26
Passive Transport
No energy required
Types of Passive Transport:
Diffusion (the net movement of particles from a region of higher concentration to a region of lower concentration)
Osmosis-Aquaporins allow water to move through the cell membrane
Facilitated Diffusion( with help of membrane proteins
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Hypotonic solution
The solution has less solute than the cell
This can cause the cell to swell as water moves into the cell to establish equal concentration
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Hypertonic solution
The solution has more solute than the cell
This can cause the cell to shrink as water diffuses out of the cell to establish equal concentration
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Isotonic solution
The solution has equal amounts of solute as the cell
Water molecules move equally in both directions
The cell is happy
30
Dynamic Equilibrium
a state where opposing processes occur at the same rate, resulting in no observable overall change in a system
31
What is photosynthesis?
the process by which plants and other organisms use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar (glucose)
32
Chemical Equation of Photosynthesis
6CO2 + 6H2O + Light Energy → C6H12O6 + 6O2.
carbon dioxide +water +light energy-> glucose and oxygen
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What organisms undergo photosynthesis?
plants and algae
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Where does photosynthesis take place?
chloroplasts of plant cells
35
Light Dependent Reactions
takes place in thylakoid membrane
1.Pigments in Photosystem II absorb light, which breaks water molecules and excites electrons
2. Excited electrons leave Photosystem II and travel down the electron transport chain towards Photosystem I. At the same time, H+ ions are pumped via active transport across the thylakoid membrane into the thylakoid, creating a positive charge inside.
3.Electrons are re-energized in Photosystem I.
4.Electrons leave Photosystem I and travel down the electron transport chain. The electrons are eventually picked up by the electron carrier NADP+, which becomes NADPH.
5. H+ ions diffuse out of the thylakoid, passing through ATP synthase, which creates ATP.
36
Calvin Cycle
takes place in the stroma
1.Carbon fixation - each carbon dioxide molecule is added to a five-carbon molecule by an enzyme
2.The 6-carbon compound splits into two 3-carbon compounds. Phosphate groups from ATP and electrons from NADPH are added to make 3-carbon sugars.
3.One of the 3-carbon sugars is used to make organic compounds, like carbs and high-energy sugars (like glucose), which are stored for later.
4. The other 3-carbon sugars are used to regenerate the 5-carbon molecule from the beginning.
37
Why is chlorophyll green?
because it absorbs most colors of light except for green, which it reflects, making plants appear green
38
What is cellular respiration?
a metabolic process that converts the chemical energy in nutrients, like glucose, into a usable form of energy called ATP (adenosine triphosphate)
39
Chemical Equation of Cellular Respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)
glucose+oxygen-> carbon dioxide+ water+ energy
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What organisms undergo cellular respiration?
animals, plants, fungi, bacteria, archaea, and protists
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Where does cellular respiration take place?
mitochondria
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Glycolysis
a series of reactions that extract energy from glucose by splitting it into two three-carbon molecules called pyruvates
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Krebs Cycle (Citric Acid Cycle)
a series of chemical reactions that extract energy from molecules, primarily in aerobic organisms.
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Electron Transport Chain
a series of protein complexes and molecules that transfer electrons from electron donors to electron acceptors, releasing energy in the process
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ATP Synthase
a crucial enzyme that generates ATP, the primary energy currency of cells, by harnessing the energy from a proton gradient
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Aerobic Cellular repsiration
a metabolic process that converts glucose and oxygen into energy (ATP), carbon dioxide, and water
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anaerobic respiration
occurs in the absence of oxygen
alcoholic fermentation-> biological method wherein the sugar gets transformed into carbon dioxide and alcohol
lactic acid fermentation-> a metabolic process where glucose or other sugars are converted into energy (ATP) and the byproduct lactate (lactic acid in solution)
48
Problems with cell size; surface area to volume ratio
The cell’s volume increases at a faster rate than its surface area when it gets larger.
The cell’s size is limited by its ability to keep up with:
Incoming nutrients/outgoing waste
Protein production by DNA
→ can lead to information overload! DNA overwhelmed, cannot control such a large cell
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What is cell division and its product?
the process by which one cell divides into two daughter cells
Each daughter cell is genetically identical to the parent cell, and results in the same number of chromosomes.
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What happens in interphase of mitosis?
Interphase - cell not dividing - most of time
Cell growth (G1 phase)
DNA replication (S phase)
Final preparation for mitosis (G2 phase)
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What happens in cytokinesis in mitosis?
cell membrane/ cytoplasm divides in two
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What happens in mitosis?
Mitosis (PMAT): division of the nucleus, occurs in 4 stages:
Prophase:
Nucleus breaks down, spindle forms and attaches to centromere, chromatin condenses to form chromosomes
Metaphase:
Sister chromatids line up along the equator of the cell
Anaphase:
Sister chromatids are split apart (now becoming individual chromosomes) and move towards opposite ends of the cell
Telophase:
Nuclei reform (2), spindle detaches and breaks down, chromosomes unravel to form chromatin
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Cell Cycle Control
internal regulators:Allows the cell cycle to proceed only if certain processes (checkpoints) have happened inside the cell ex. cyclins and kinases
external regulators: direct cells to speed up or slow down reaction. ex. growth hormones
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Tumors
Masses of cells formed from uncontrolled division; may damage surrounding tissues
benign-> a mass of cancer cells all in one place
malignant-> larger masses of cancer cells in which cells start to break away from the mass
metastasis-> when malignant tumors lose cancer cells and they start to spread around the body, forming new tumors
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What is cancer?
uncontrolled cell growth and division
Disorder in which the body’s own cells lose the ability to control cell growth
Cancer cells do not respond to cell cycle regulators
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Diploid vs. Haploid
Diploid cells have two sets of chromosomes (2n), one from each parent, while haploid cells have only one set (n)
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Meiosis
general purpose: to produce gametes (sperm and egg cells) for sexual reproduction and to generate genetic diversity
products: gametes (egg and sperm cells)
Crossing over-> When two chromosomes — one from the mother and one from the father — line up, parts of the chromosome can be switched. The two chromosomes contain the same genes, but may have different forms of the genes.
independent assortment-> inheriting an allele has nothing to do with inheriting an allele for any other trait
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What is a gamete?
a reproductive cell of an animal or plant
in animals, female: egg
male: sperm
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What is fertilization?
when one male and one female gamete come together to form a zygote
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how sex is decided
Eggs always carry an X chromosome.
Sperm can carry either an X or a Y chromosome.
If a sperm carrying an X chromosome fertilizes the egg, the resulting combination is XX, leading to a female (girl).
If a sperm carrying a Y chromosome fertilizes the egg, the resulting combination is XY, leading to a male (boy)
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Sources of genetic variation in sexually reproducing organisms
meiosis, random fertilization, and mutations
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Law of Segregation
parental genes must separate randomly and equally into gametes during meiosis so there is an equal chance of the offspring inheriting either allele. No allele is favored or has an advantage over another.
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Trait, gene, allele
Trait:a specific characteristic or feature of an organism that can be observed or measured
Gene: the fundamental unit of heredity, a segment of DNA that contains instructions for building and maintaining an organism
Allele-> different versions of the same gene
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Genotype vs Phenotype
A genotype is an organism's genetic makeup, while a phenotype is the observable characteristics or traits of that organism
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Dominant vs. Recessive
A dominant allele trait will be expressed even if only one copy is present, while a recessive allele trait will only be expressed if two copies are present
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Heterozygous vs. Homozygous
Homozygous means having two identical alleles, while heterozygous means having two different alleles for the same gene
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Incomplete dominance
somewhere in between the other phenotypes. An example of this is in snapdragons.
RR=red
rr=white
Rr=pink
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Codominance
Both alleles are expressed equally in BW
ex. chickens
BB=black
WW=white
BW=black and white speckled
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Sex linked disorders
genetic conditions caused by mutations in genes located on the X chromosome
ex. color blindness
70
Structure of a nucleotide
Made up of nucleotides which contain three parts:
Deoxyribose Sugar
Phosphate
Nitrogenous Base (A, T, C, G
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Structure of dna
DOUBLE HELIX
Backbone is made of sugar-phosphate
made of nucleotides
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DNA Replication
purpose: where a cell can double its DNA before cell division
location: in DNA (nucleus)
product: two identical DNA molecules, each composed of one original (parental) strand and one newly synthesized strand
Base pairs
Adenine<->Thymine
Cytosine<-> Guanine
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Structure of RNA nucleotide
phosphate
ribose
nitrogenous base (a,c,g,u)
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DNA vs RNA
DNA is typically double-stranded, while RNA is usually single-stranded
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Types of RNA
mRNA->carries the genetic code, transcribed from DNA, to the ribosomes
tRNA->bring specific amino acids to the ribosomes, matching them to the mRNA codons
rRNA->forms the structure of ribosomes
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Transcription
location:nucleus
purpose:to create a messenger RNA (mRNA) molecule from a DNA template
product: a single-stranded RNA molecule that is complementary to one strand of the DNA
base pairs
Adenine<->Uracil
Thymine-> Adenine
Cytosine<-> Guanine
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Central Dogma of Biology
DNA-> RNA-> Polypeptide (protein)
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mRNA splicing
exons-> become mature mRNA
introns-> discarded
cap and poly-a tail keeps mRNA from degrading
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Translation
location: ribosomes
purpose: directs the addition of amino acids to create proteins
product-> Polypeptide chain to create proteins
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Promoter
a specific DNA sequence that signals the start of a gene and serves as a binding site for RNA polymerase and other proteins to initiate transcription
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Product of protein synthesis
Polypeptide chain
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general function of proteins
structural support, enzyme activity, hormone signaling, and immune defense
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What is evolution?
the process by which populations of living organisms change over generations.
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Natural Selection
a key mechanism of evolution, where organisms with advantageous traits are more likely to survive and reproduce, passing those traits to their offspring
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Differential reproductive success
the phenomenon where some individuals in a population produce more offspring than others, often due to advantageous traits that enhance their survival and/or reproductive capabilities
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Fitness
an organism's ability to survive, reproduce, and pass on its genes to the next generation in a specific environment
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Artificial selection
the process where humans intentionally breed plants and animals for specific desirable traits
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Evolution by descent with modification
describing how species change over time from their ancestors, with each generation inheriting traits from the previous one, potentially with slight variations
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Common descent
a biological theory stating that all living organisms on Earth are descended from a single common ancestor
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Common ancestry
the idea that all living organisms are descended from a single, ancient ancestor
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5 types of Evidence of evolution
Comparative anatomy (homologous structures-> share similar structures but diff. purposes-> shows common ancestry)
embryology
fossil evidence
biogeography
DNA evidence and molecular biology
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Types of selection
Directional-> one extreme is favored
Stabilizing-> the median is favored
Disruptive-> both extremes are favored
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Speciation by reproductive isolation
behavioral
geographic
temporal (timing)
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Ecology
Study of interactions between organisms and their surroundings
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levels of organization
organism
population
community
ecosystem
biome
biosphere
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Biotic and abiotic factors
biotic: living: predation, pollination
abiotic: non-living: soil weather, climate
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Producers
an organism found at the bottom of a food chain/web
-they can make their own food (autotroph)
chemosynthesis and photosynthesis
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Consumers and their diets
herbivores-> only plants
carnivores-> only meat
omnivores-> plants and meat
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Negative feedback loops
A stimulus produces a response that opposed the stimulus and brings the body back to the set point.
ex. blood sugar levels
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Positive feedback loops
further increase the output
ex. childbirth/blood clotting
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Levels of Organization
cells-> tissues-> organ-> organ system-> organism
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Digestive System
converts food into small molecules that can be used by the cells of the body
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Path of food
mouth-> break down food by chewing and use saliva to bring down carbohydrates
esophagus-> passageway to stomach
stomach-> storing food, breaking it down both mechanically and chemically, and releasing it into the small intestine
small intestine-> break down food, absorb nutrients and water from digested food, and move the remaining waste into the large intestine
large intestine->absorb water and electrolytes from undigested food, forming solid waste (feces) and storing it until elimination
rectum-> stores feces
anus-> where feces comes out
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function of liver
filtering blood, metabolizing nutrients, producing bile, and storing energy
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function of pancreas
assisting in digestion and regulating blood sugar levels
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function of gallbladder
store, concentrate, and release bile
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Circulatory system
transports oxygen, nutrients, and other substances throughout the body, and remove wastes from tissues.
veins-> carry deoxygenated blood to heart
arteries -> carry oxygenated blood away from heart
capillaries- exchange of oxygen, nutrients, and waste products between the blood and the body's tissues
heart-> pump blood through body
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how blood flows through the heart
superior/inferior vena cava
right atrium
right ventricle
pulmonary artery
lungs
pulmonary vein
left atrium
left ventricle
aorta
to rest of the body
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Respiratory system
picks up oxygen from the air we inhale and releases carbon dioxide into the air we exhale
lungs->facilitate gas exchange
alveoli-> gas exchange, specifically facilitating the transfer of oxygen from inhaled air into the bloodstream and carbon dioxide from the blood into the lungs to be exhaled
diaphragm-> muscle movement that allows for breathing
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path that air travels through different structures
from the mouth to the pharynx, then the larynx, trachea, bronchi, bronchioles, and finally reaches the alveoli in the lungs
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Nervous System
collects information about the body’s internal and external environment, process that information, and responds to it
CNS-> takes in info, finds response, sends it out
PNS->enables movement, relays sensory information, and regulates vital functions like heart rate and digestion
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Neurotransmitter, neuron, synapse
synapse-> The point at which a neuron transfers an impulse to another cell
neurotransmitter->chemicals that transmit an impulse across a synapse to another cell
neuron->electrically excitable cells that transmit signals throughout the body
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Excretory System
removes metabolic waste and toxins from the body
Kidneys->remove excess water, urea and metabolic wastes from the blood
liver-> the conversion of potentially dangerous nitrogen wastes, a product of protein break down, into less toxic urea
skin-> excretes excess water, salts and a small amount of urea in sweat
lungs-> excrete carbon dioxide and a small amount of water vapor
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Endocrine System
Second communication system of the body
Slow and longer-lasting
Regulates homeostasis via glands releasing hormones
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What are the messengers called, and what body system do they travel through?
(endocrine system)
messengers-> hormones
travel through bloodstream
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immune system
defend the body against disease-causing microorganisms and harmful substances
antibodies->recognizing and binding to specific antigens, tagging them for destruction or neutralizing them directly
white blood cells-> act as the first line of defense against infection and disease, identifying and destroying harmful invaders like bacteria, viruses, and other pathogens
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Structure of a virus
a nucleic acid (either DNA or RNA) and a protein coat called a capsid
