Final Study Guide Flashcards
(149 cards)
1
Q
What are monomers?
A
The subunit that serves as a building block of a polymer
Examples include monosaccharides for carbohydrates, amino acids for proteins, and nucleotides for nucleic acids.
2
Q
What is a polymer?
A
A large molecule consisting of many similar or identical monomers linked together by covalent bonds
3
Q
What are the monomers of carbohydrates?
A
Monosaccharides
4
Q
What are the monomers of proteins?
A
Amino acids
5
Q
What are the monomers of nucleic acids?
A
Nucleotides
6
Q
What is the structure of water?
A
2 hydrogen and 1 oxygen bonded together with covalent bonds
7
Q
What property makes water polar?
A
The unequal sharing of electrons between oxygen and hydrogen atoms
8
Q
What is cohesion in relation to water?
A
Water molecules attached to each other
9
Q
What is adhesion in relation to water?
A
Water molecules attached to other things
10
Q
What is surface tension?
A
Hydrogen bonds resist being stretched
cohesion and adhesion
11
Q
Which elements are primarily found in biological macromolecules?
A
Carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur
12
Q
What is dehydration synthesis?
A
Monomers are joined by removal of OH from one monomer and H from another at the site of bond formation
13
Q
What is hydrolysis?
A
Monomers are released by the addition of a water molecule
14
Q
What determines the structure and function of polymers?
A
The way their monomers are assembled
15
Q
What are the structural components of nucleotides?
A
- Nitrogenous base
- Five carbon sugar (deoxyribose or ribose)
- Phosphate group
16
Q
What determines the overall shape of a protein?
A
The specific order of amino acids in a polypeptide
17
Q
What is a peptide bond?
A
The bond formed when two amino acids combine
18
Q
What is the primary structure of proteins?
A
A long chain of amino acids with an amino end and carboxyl end
19
Q
What is the secondary structure of proteins?
A
Local folding of the amino acid chain into elements such as alpha-helices and beta sheets
20
Q
What is the tertiary structure of proteins?
A
The overall three-dimensional shape of the protein
when the strand begins to fold in on itself
21
Q
What is quaternary structure in proteins?
A
Arises from non-covalent interactions between multiple polypeptide units
22
Q
What is the function of ribosomes?
A
Synthesizes protein according to mRNA sequence
23
Q
What are the three types of ribosomes?
A
- mrna
- trna
- rrna
24
Q
What is the role of the endoplasmic reticulum (ER)?
A
Synthesizes proteins and lipids, and detoxifies certain molecules
25
What is the function of the Golgi complex?
Correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking
26
What is the powerhouse of the cell?
Mitochondria
27
What is the role of lysosomes?
Break down particles that don’t belong in the cell and digest food
28
What is a vacuole?
A membrane-bound sac that plays differing roles in both plants and animals
29
What is the role of chloroplasts?
Involved in photosynthesis
30
What is the fluid mosaic model?
Describes the structure of cell membranes consisting of phospholipid molecules embedded with proteins
31
What is passive transport?
The net movement from high concentration to low concentration without direct input of metabolic energy
32
What is active transport?
Requires direct input of energy to move molecules from low concentration to high concentration
33
What is endocytosis?
The process of the cell taking in macromolecules by forming new vesicles
34
What is exocytosis?
The process of vesicles fusing with the cell membrane to release contents outside the cell
35
What is the significance of surface area-to-volume ratios in cells?
Affects the ability of a biological system to obtain resources and eliminate waste
36
What is the structure of the phospholipid bilayer?
Hydrophilic phosphate regions oriented towards aqueous environments and hydrophobic fatty acid regions facing each other
37
What is the process by which the plasma membrane engulfs a particle and transports it into the cell?
Endocytosis
## Footnote
This process involves forming a vesicle around the particle.
38
What happens to the vesicle that engulfs a particle?
It fuses with a lysosome containing digestive enzymes
## Footnote
This allows the food to be broken down into usable parts.
39
What is exocytosis?
The process of transporting proteins out of the cell
## Footnote
Involves vesicles pinching off from the Golgi apparatus and fusing with the cell membrane.
40
What are aquaporins?
Integral membrane proteins that facilitate the passage of water into the cell
## Footnote
They are necessary because very few water molecules can pass through the membrane directly.
41
What is the primary function of photosynthesis?
To capture energy from sunlight and produce sugars
## Footnote
This process uses water, light, and carbon dioxide to create oxygen and sucrose.
42
What is the equation for photosynthesis?
6CO2 + 6H2O + Light Energy ⇒ C6H12O6 + 6O2
## Footnote
This represents the transformation of carbon dioxide and water into glucose and oxygen.
43
Where does photosynthesis occur in plants?
In the chloroplasts
## Footnote
Chloroplasts convert solar energy into chemical energy.
44
What are the main components of chloroplasts?
* Outer Membrane
* Inner Membrane
* Intermembrane Space
* Thylakoid Membrane
* Stroma
## Footnote
These structures help compartmentalize functions within the chloroplast.
45
What are the photosynthetic pigments?
* Chlorophyll a
* Chlorophyll b
* Carotenoids
## Footnote
These pigments absorb different wavelengths of light to convert solar energy.
46
What do the light reactions of photosynthesis produce?
ATP and NADPH
## Footnote
These products are used in the Calvin Cycle.
47
What is the role of Photosystem 2 in the light reactions?
It absorbs sunlight, excites chlorophyll, and initiates the electron transport chain
## Footnote
This process also involves the splitting of water molecules, creating oxygen.
48
What is the Calvin Cycle?
A process that uses ATP and NADPH to convert CO2 into sugar
## Footnote
This occurs in the stroma of the chloroplast.
49
What are the three main steps of the Calvin Cycle?
* Carbon fixation
* Reduction
* Regeneration of RuBP
## Footnote
This cycle is also known as the C3 pathway.
50
What is glycolysis?
A biochemical pathway that converts glucose into pyruvate, producing ATP and NADH
## Footnote
This process occurs in the cytoplasm.
51
What is produced during glycolysis?
* 2 ATP
* 2 NADH
* 2 Pyruvate
## Footnote
Glycolysis is essential for cellular respiration.
52
What occurs during the Krebs Cycle?
Carbon dioxide is released, ATP is synthesized, and electrons are transferred to NADH and FADH2
## Footnote
This cycle occurs in the mitochondria.
53
What is the function of the electron transport chain?
Transfers energy from electrons to establish an electrochemical gradient
## Footnote
This gradient is crucial for ATP production.
54
What is oxidative phosphorylation?
The process of generating ATP using the proton gradient established by the electron transport chain
## Footnote
This occurs in cellular respiration.
55
What is fermentation?
A process that allows glycolysis to continue in the absence of oxygen
## Footnote
It produces organic molecules like alcohol and lactic acid as waste products.
56
What is the main function of cellular respiration?
To produce ATP from biological macromolecules
## Footnote
It involves lipids, proteins, and carbohydrates.
57
What are the differences between photosynthesis and cellular respiration?
* Photosynthesis: terminal electron acceptor is NADP+, occurs in chloroplasts, produces food
* Cellular Respiration: terminal electron acceptor is oxygen, occurs in mitochondria, produces ATP
## Footnote
Both processes involve electron transport chains and proton gradients.
58
What is paracrine signaling?
Communication between nearby cells through the release of chemical messengers
## Footnote
This type of signaling is crucial during development.
59
What is autocrine signaling?
A cell signals to itself by releasing a ligand that binds to its own receptors
## Footnote
This is important for reinforcing cellular identity.
60
What is endocrine signaling?
Long-distance communication using the circulatory system to distribute signals
## Footnote
Hormones are a key component of this signaling type.
61
What are gap junctions?
Channels that connect neighboring cells, allowing small signaling molecules to diffuse
## Footnote
They enable direct communication between cells.
62
What is signal transduction?
The process that occurs after a signaling molecule binds to a receptor
## Footnote
It involves a series of intracellular signaling cascades.
63
What is the first step in signal transduction?
Reception of the ligand by the receptor protein
## Footnote
This often changes the shape of the receptor.
64
What are second messengers?
Molecules that relay and amplify signals inside the cell
## Footnote
They play a critical role in signal transduction pathways.
65
What is negative feedback?
A mechanism that maintains homeostasis by returning a system to its target set point
## Footnote
It regulates physiological processes in response to changes.
66
What is positive feedback?
A mechanism that amplifies responses and processes in biological systems
## Footnote
It moves the variable further away from the initial set point.
67
What is an example of positive feedback?
Blood vessel injury leading to clotting factor activation
## Footnote
This process amplifies the response to the injury.
68
What is an example of negative feedback in homeostasis?
Trying to bring the body back to “normal” when it has reached abnormality
## Footnote
Negative feedback mechanisms help maintain stability in biological systems.
69
How do positive feedback mechanisms work?
They amplify responses and processes in biological organisms, moving the variable farther away from the initial set point
## Footnote
Positive feedback continues until a desired outcome is achieved.
70
What triggers the activation of clotting factors in blood vessel injury?
Molecules released from injured cells
## Footnote
This initiates a cascade that promotes blood clot formation.
71
Define phosphorylation.
The addition of a phosphate group to one or more sites on a protein, altering its activity
## Footnote
Phosphorylation often acts as a switch, affecting protein function.
72
What catalyzes the transfer of phosphate groups during phosphorylation?
Kinase enzymes
## Footnote
Different kinases target various proteins for phosphorylation.
73
What are the two highly regulated processes for eukaryotic cell division?
Mitosis and Meiosis
## Footnote
These processes ensure the transmission of genetic information.
74
What is the result of meiosis?
Daughter cells with half the number of chromosomes of the parent cell
## Footnote
Meiosis produces haploid gametes.
75
What is the longest phase of the cell cycle?
Interphase
## Footnote
It consists of G1, S, and G2 phases.
76
What happens during the S phase of interphase?
Chromosomes duplicate
## Footnote
This is essential for genetic material transfer during mitosis.
77
What is the role of mitosis?
Ensures the transfer of a complete genome from a parent cell to two genetically identical daughter cells
## Footnote
Mitosis is crucial for growth and tissue repair.
78
List the sequential steps of mitosis.
* Prophase
* Prometaphase
* Metaphase
* Anaphase
* Telophase
## Footnote
Each step has specific roles in chromosome separation.
79
What occurs during prophase?
Nuclear envelope begins to disappear and chromatin condenses into chromosomes
## Footnote
The mitotic spindle starts to form.
80
What marks the metaphase stage?
Chromosomes align in the middle of the cell
## Footnote
This alignment is crucial for proper chromosome separation.
81
What happens during anaphase?
Sister chromatids are pulled to opposite sides of the cell
## Footnote
This separation ensures each daughter cell receives identical genetic material.
82
What is the G0 phase?
A stage where a cell no longer divides but can reenter the cell cycle
## Footnote
Cells can exit the cycle if they do not receive the go-ahead signal.
83
What is the G1 checkpoint responsible for?
Checks cell size, growth factors, and the environment
## Footnote
Cells must pass this checkpoint to synthesize DNA and divide.
84
What does the MPF control in the G2 checkpoint?
Movement of G2 into the cell cycle by phosphorylating and activating proteins
## Footnote
MPF is crucial for chromosome condensation and nuclear envelope breakdown.
85
What is the function of cyclins in the cell cycle?
Cyclins regulate the activity of cyclin-dependent kinases (CDKs)
## Footnote
Their levels fluctuate throughout the cell cycle.
86
What is density-dependent inhibition?
A process where crowded cells stop dividing
## Footnote
This mechanism helps prevent overgrowth.
87
What is apoptosis?
A type of programmed cell death that disposes of cell components orderly
## Footnote
Apoptosis is crucial for maintaining healthy tissue.
88
What does nondisjunction lead to in meiosis?
Aneuploidy, which results in gametes with too many or too few chromosomes
## Footnote
This can lead to genetic disorders.
89
What is the purpose of meiosis?
To produce genetic variation in gametes
## Footnote
This is essential for evolution and adaptation.
90
What is Mendel's Law of Segregation?
The alleles of a given locus segregate into separate gametes
## Footnote
This law is fundamental to understanding inheritance patterns.
91
Define genotype.
The set of alleles carried by an organism
## Footnote
Genotype determines the potential traits of an organism.
92
What is crossing over?
The exchange of genetic material between homologous chromosomes during meiosis
## Footnote
This process increases genetic diversity.
93
What does fertilization restore in sexually reproducing organisms?
The diploid number of chromosomes
## Footnote
It combines genetic material from two parents.
94
What is Mendel’s Law of Independent Assortment?
Alleles of two (or more) different genes get sorted into gametes independently of one another.
95
What is the role of fertilization in genetics?
Involves the fusion of two haploid gametes, restoring the diploid number of chromosomes and increasing genetic variation.
96
What happens during crossing over in interphase?
It causes the cell to create variation.
97
How does the arrangement of chromosomes during metaphase affect genetic variation?
The order and orientation of chromosomes lining up is completely random.
98
How can rules of probability be applied in genetics?
To analyze passage of single-gene traits from the parent to the offspring.
99
What is the probability of obtaining ccdd from CcDd x CcDd?
1/16.
100
What is phenotypic plasticity?
Occurs when individuals with the same genotype exhibit different phenotypes in different environments.
101
What are three major examples of environmental factors affecting phenotype?
* Seasons
* pH levels
* Population density
102
What is the primary source of heritable information?
DNA, and in some cases RNA.
103
What are the characteristics of DNA?
* Double stranded
* Deoxyribose sugar
* Nitrogenous bases: TCAG
104
What are the characteristics of RNA?
* Generally single stranded
* Ribose sugars
* Nitrogenous bases: UCAG
105
What are nucleotides composed of?
* Phosphate group
* Sugar
* Nitrogenous base
106
What type of bonding occurs between nitrogenous bases in DNA?
Hydrogen bonds.
107
What are purines and pyrimidines?
* Purines: Adenine, Guanine
* Pyrimidines: Thymine (Uracil), Cytosine
108
What is the directionality of the DNA molecule?
Antiparallel.
109
What is the 5' end of a DNA strand?
The phosphate group is bound to the carbon at the 5th position.
110
What is the 3' end of a DNA strand?
The open end of the DNA strand starting from the 5' end.
111
What is the difference between prokaryotic and eukaryotic chromosomes?
* Prokaryotes have circular chromosomes
* Eukaryotes have linear chromosomes.
112
What regulates gene expression in eukaryotes?
Histones pack chromatin and chemical modifications can change chromatin organization.
113
What is semiconservative DNA replication?
Each daughter molecule will have one new strand and one old strand.
114
What are the main enzymes involved in DNA replication?
* Helicase
* Topoisomerase
* DNA Polymerase
* Primase
* Ligase
* Single Stranded Binding Proteins
115
What is the role of DNA polymerase III?
Responsible for adding DNA nucleotides to RNA primers.
116
What is the leading strand in DNA replication?
Synthesized continuously in the 5’ to 3’ direction.
117
What are Okazaki fragments?
Segments synthesized on the lagging strand during DNA replication.
118
What is the function of DNA ligase?
Joins fragments in lagging strands.
119
What is the process of DNA proofreading?
DNA Polymerase replaces incorrect nucleotides with correct ones.
120
What is the flow of genetic information during protein synthesis?
Transcription ⇒ mRNA processing ⇒ Translation.
121
What is the function of mRNA?
Carries information from DNA to ribosome.
122
What is the role of tRNA in translation?
Binds specific amino acids and has anti-codon sequences that base pair with mRNA.
123
What is the function of rRNA?
Building blocks of ribosomes.
124
What is the process of transcription?
DNA strands are turned into RNA strands.
125
What occurs during mRNA processing?
Addition of poly-A-tail, GTP cap, removal of introns, splicing and retention of exons.
126
What is the difference between prokaryotic and eukaryotic translation?
* Prokaryotes: Translation occurs simultaneously with transcription
* Eukaryotes: Translation occurs on rough endoplasmic reticulum.
127
What is a retrovirus?
Virus that uses RNA as its genetic material and converts it into DNA using reverse transcriptase.
128
What is DNA methylation?
Addition of methyl groups to DNA nucleotides, generally reducing transcription.
129
What is the role of miRNA?
Functions in RNA silencing and post-transcriptional regulation of gene expression.
130
What are mutations?
Main cause of genetic variation; can lead to changes in phenotype.
131
What is the function of a promoter in gene regulation?
DNA sequence where RNA polymerase binds to start transcription.
132
What happens when lactose is present in the lactose operon?
Allolactose inactivates the repressor, allowing RNA polymerase to transcribe proteins needed to digest lactose.
133
What is the definition of miRNA?
A small non-coding RNA molecule containing about 22 nucleotides that functions in RNA silencing and post-transcriptional regulation of gene expression.
## Footnote
miRNA can degrade mRNA or block translation depending on the complementarity of the bases.
134
What is the main cause of genetic variation?
Mutations.
## Footnote
Some mutations cause changes in phenotype, such as the mutated CFTR protein leading to cystic fibrosis.
135
How can DNA mutations affect phenotype?
Alterations in DNA can lead to changes in type or amount of protein produced.
## Footnote
The effect of these mutations can be positive, negative, or neutral, depending on environmental conditions.
136
What is Horizontal Acquisition?
The transmission of DNA between different genomes, distinct from vertical gene transfer.
## Footnote
Horizontal Acquisition occurs in eukaryotes, prokaryotes, and between chloroplasts, nucleus, and mitochondrion.
137
What are the three ways prokaryotes share or transfer DNA?
* Transformation
* Transduction
* Conjugation
## Footnote
Transformation involves introducing DNA via plasmid, transduction involves viral transmission, and conjugation involves direct cell-to-cell transfer.
138
What is Transposition in genetics?
The removal and transfer of a segment of DNA from one site to another of the same or different chromosome.
## Footnote
It can interrupt genes, disrupt regulation, and increase recombination likelihood.
139
What occurs during Transformation in bacteria?
A bacterium takes in DNA from its environment, often from other bacteria.
## Footnote
If the DNA is a plasmid, it can be copied and passed to descendants.
140
What is Transduction?
The process where viruses that infect bacteria move short pieces of chromosomal DNA from one bacterium to another.
## Footnote
These viruses are called bacteriophages.
141
What is Conjugation in bacterial DNA transfer?
DNA is transferred from one bacterium to another via a pilus.
## Footnote
The donor cell typically contains a fertility factor that codes for the sex pilus.
142
What is Gel Electrophoresis used for?
To separate DNA fragments based on size using an electric charge.
## Footnote
DNA is cut with restriction enzymes before electrophoresis.
143
What is DNA Sequencing?
A genetic engineering technique that determines the order of nucleotides in DNA.
## Footnote
It can be used for organism identification or forensic analysis.
144
What is Gene Cloning?
The process of taking the nucleus of a somatic cell from a desired animal and fusing it with an egg cell to create a clone.
## Footnote
This technique is used in various forms of biotechnology.
145
What is Natural Selection?
A process where individuals with certain inherited traits survive and reproduce at higher rates due to those traits.
## Footnote
This mechanism of evolution was proposed by Charles Darwin.
146
What are the components needed for the mechanism of natural selection?
* Variation
* Reproduction
* Competition
* Fitness
* Evolution
## Footnote
These components interact to drive the evolution of species.
147
What are sources of variation in a population?
* Mutations
* Sexual reproduction
## Footnote
Mutations introduce random changes, while sexual reproduction mixes alleles, leading to new phenotypes.
148
True or False: Natural selection acts on genotypic variations in populations.
False.
## Footnote
Natural selection acts on phenotypic variations.
149
What is the significance of environmental changes in natural selection?
They can apply new selective pressures to populations, affecting which traits are advantageous.
## Footnote
This leads to changes in the population's genetic makeup over time.
