AAMC FL 1: Bio/Biochem Flashcards
(197 cards)
1
Q
- Reviewable content: If a mutation is only expressed in somatic/cancerous cells, can it be inherited by offspring?
- Date: 6/16/2022
- Question: 3
- Content: 1C: Transmission of heritable info from generation to generation and the processes that increase genetic diversity
- Skill: 2: Scientific reasoning
- Error Description/ Category: Missed and misinterpreted important info in the passage
A
NO: Mutations that are expressed in somatic/ cancerous can’t be inherited by offspring OR at least its not v likely. These mutations would have to occur in the germ line for them to be inherited by the offspring
2
Q
- Reviewable content: What usually codes for a gene, an intron or an exon? Which is usually spliced out?
- Date: 6/16/2022
- Question: 5
- Content: 1B: Transmission of genetic info from the gene to the protein
- Skill: Scientific reasoning and problem solving
- Error Description/ Category: Guessed
A
- Exons usually code for genes, not introns, so they are not spliced out
- Introns are non-coding sections of an RNA transcript or the DNA encoding and are .: spliced out before the RNA is translated to protein
3
Q
- Reviewable content: What can happen to exons at splice acceptor sites when mutations occur?
- Date: 6/16/2022
- Question: 5
- Content: 1B: Transmission of genetic info from the gene to the protein
- Skill: 2: Scientific reasoning and problem solving
- Error Description/ Category: Guessed
A
Splice acceptor sites can allow exons to be omitted when mutations occur
4
Q
- Reviewable content: What are the function of chaperone proteins? What about clathrin?
- Date: 6/16/2022
- Question: 5
- Content: 1A: Structure and function of proteins and their constituent amino acids
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
- Chaperone proteins facilitate proper protein folding and inhibit the formation of non functional protein aggregates
- Clathrin functions in the formation of vesicles for intracellular trafficking
5
Q
- Reviewable content: What is a nuclear localization signal?
- Date: 6/16/2022
- Question: 8
- Content:2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 2: Scientific reasoning
- Error Description/ Category: Missed and misinterpreted important info in the passage
A
A sequence that tags the protein for it to be transported into the nucleus
6
Q
- Reviewable content: What is a signal sequence? Where are they located? Where are they normally found?
- Date: 6/16/2022
- Question: 8
- Content:2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 2: Scientific reasoning
- Error Description/ Category: Missed and misinterpreted important info in the passage
A
- Signal to a ribosome that translation need to be continued in the rough endoplasmic reticulum
- 5’ region of a mature mRNA sequence
- On a protein that is secreted or that will locate to the cell membrane
7
Q
- Reviewable content: What are two things that are absent in mature mRNA?
- Date: 6/16/2022
- Question: 8
- Content:2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 2: Scientific reasoning
- Error Description/ Category: Missed and misinterpreted important info in the passage
A
Introns and promoters
8
Q
- Reviewable content: What is chemiosomosis?
- Date: 6/16/2022
- Question: 10
- Content: 1D: Principles of bioenergetics and fuel molecule metabolism
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
The actual production of ATP in cellular respiration that involves the pumping of protons through the special channels in the mem of the mitochondria from the inner to the outer compartment -> This proton gradient is what then drive ATP synthase to produce ATP
9
Q
- Reviewable content: What is the only step in cellular respiration where NAD+/ NADH is neither oxidized nor reduced? Glycolysis, chemiosmosis, citric acid/ Kreb’s/TCA cycle, or the ETC?
- Date: 6/16/2022
- Question: 10
- Content: 1D: Principles of bioenergetics and fuel molecule metabolism
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
Chemiososmosis
10
Q
- Reviewable content: During the invitation of muscle contraction, myosin binds to actin after troponin binds to what? AKA what ion plays a role in myosin- actin binding during skeletal contraction? What does it allow?
- Date: 6/16/2022
- Question: 12
- Content:3B: Structure and integrative functions of the main organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
- Ca2+ ions
- They bind to troponin and allows tropomyosin to move .: freeing the site of interaction bt actin and myosin
11
Q
- Reviewable content: What is the total number of fused rings present in a steroid?
- Date: 6/16/2022
- Question: 13
- Content: 2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
A steroid is composed of a 6-6-6-5 fused ring assembly which is a total of 4 fused rings
12
Q
- Reviewable content: Let’s say someone has a diseases that results in motor seizures due to massive synchronous firing of neurons in a small area of the brain. A drug for the treatment of this disease would be most effective if it caused what?
- Date: 6/16/2022
- Question: 14
- Content:3A: Structures and functions of the nervous systems and ways in which these symptoms could coordinate the organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Couldn’t decide bt two answers
A
An increase in the the threshold that would make it more challenging for a neuron to fire an action potential. This would reduce the frequency of downstream neuron depolarization molecules resulting in a relief of symptoms
13
Q
- Reviewable content: Influx/ efflux of what ions leads to neuron depolarization and thus action potenital firing? Where are there higher concentrations of these ions in the cell? When does repolarization and hyperpolarization occur?
- Date: 6/16/2022
- Question: 14
- Content:3A: Structures and functions of the nervous systems and ways in which these symptoms could coordinate the organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Couldn’t decide bt two answers
A
- There is more sodium outside of the cell and there is less inside the cell, whereas there is more potassium inside the cell and less outside of the cell
- Influx of sodium coming into the cell causes depolarization .: influx of potassium causes repolarization
- Hyperpolarization can be caused by opening channels that allow positive ions to move out of the cell so efflux of potassium ions while sodium channels rest
14
Q
- Reviewable content: What happens to the membrane potential as depolarization occurs?
- Date: 6/16/2022
- Question: 14
- Content:3A: Structures and functions of the nervous systems and ways in which these symptoms could coordinate the organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Couldn’t decide bt two answers
A
It becomes more positive or less negative since resting potential is already negative
15
Q
- Reviewable content: When concentrated urine is being produced, in which region of the kidney will the filtrate reach its highest concentration? Why?
- Date: 6/16/2022
- Question: 15
- Content: 3B: Structure and integrative functions of the main organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Guessed but still got it right so wanted to review the concept
A
The medullary portion of the collecting duct: This is the final structure in which water reabsorption occurs, which concentrates filtrate. The medullary portion of the collecting duct is the last portion of the tubules where reabsorption can occur. In this portion the tubule that follows, there will be no more reabosrption
16
Q
Reviewable content: What is expected in kinetic studies in terms of protein activity? What does this mean?
- Date: 6/16/2022
- Question: 16
- Content: 1A: Structure and function of proteins and their constituent amino acids
- Skill: 3: Reasoning about the design and execution of research
- Error Description/ Category: Misinterpreted the graph and question -> Didn’t realize it said NOT
A
- In kinetic studies, protein activity is just expected to increase w temp, assuming the protein does not thermally denature
- This means that they are studying some other aspect (in this question it was the presence of cholesterol AKA membrane fluidity to see how it played a role in protein activity) -> They weren’t focused on temp
17
Q
- Reviewable content: What is the function of Na+K+ ATPase during a neuronal action potential?
- Date: 6/16/2022
- Question: 18
- Content:3A: Structures and functions of the nervous systems and ways in which these symptoms could coordinate the organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Honestly just forgot
A
Restoration of the resting potential
18
Q
- Reviewable content: In which direction does the Na+K+ ATPase transport ions across the cell membrane upon ATP hydrolysis? Why?
- Date: 6/16/2022
- Question: 19
- Content: 2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
- 3 Na+ are transported outside the cell and 2 K+ are transported inside the cell against their concentration gradient
- Bc Na+ concentration is higher outside the cell and K+ concentration is higher inside the cell so this is done to restore the membrane potential
19
Q
- Reviewable content: What kinds of molecules can freely pass through the cell mem via simple diffusion?
- Date: 6/16/2022
- Question: 21
- Content: 2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 2: Scientific reasoning and problem solving
- Error Description/ Category: I was overthinking and couldn’t tell if the molecule was hydrophobic or not
A
Small, non polar and uncharged molecules like O2, CO2, and water
20
Q
- Reviewable content: What is the activating event of a protein kinase?
- Date: 6/16/2022
- Question: 22
- Content: 1A: Structure and function of proteins and their constituent amino acids
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Got correct but wanted to study the concepts
A
Phosphorylation
21
Q
- Reviewable content: How to active transporters work?
- Date: 6/16/2022
- Question: 24
- Content: 2A: Assemblies of molecules, cells, and groups of cells within single cellular and multicellular organisms
- Skill: 2: Scientific reasoning and problem solving
- Error Description/ Category: Missed info in the passage that said that P-GTP was an ABC transporter protein
A
They are transporter proteins w ATPase activity so they use ATP to actively transport molecules such as drugs out of cells
22
Q
- Reviewable content: How do microtubules aid in cell mitosis and meiosis?
- Date: 6/16/2022
- Question: 28
- Content: 2C: Processes of cell divisions differentiation, and specialization
- Skill: 2: Scientific reasoning and problem solving
- Error Description/ Category: Got correct but just wanted to study the concept
A
Microtubules bind to chromosomes at the level of the kinetochore and regulate their migration/ movement toward opposite poles of the cell during anaphase
23
Q
- Reviewable content: The initial filtration step in the glomerulus of the mammalian kidney occurs primarily by what? What are the 3 pressures that work tg to regulate filtration in the glomerulus?
- Date: 6/16/2022
- Question: 29
- Content: 3B: Structure and integrative functions of the main organ systems
- Skill: 1: Knowledge of scientific principles
- Error Description/ Category: Guessed but still got it right so wanted to review the concept
A
- Passive flow due to a pressure difference: There are 3 pressures that work tg to regulate filtration in the glomerulus -> Capillary pressure, capsular hydrostatic pressure, and blood colloid osmotic pressure
- The glomerular capillary pressure will force filtrate from a capillary into Bowman’s capsule and the other two forces promote movement of the filtrate in the opposite direction
24
Q
Enzymes alter the rate of chemical reactions by doing what 3 things?
A
Co-localizing substrates, altering local pH, altering substrate shape, NOT substrate primary structure
25
Why might a new amino acid like orthinine not be likely to be found in proteins synthesized in vivo?
Proteins are generated during translation. In this process, mRNA triplets are read by ribosomes, and tRNA molecules provide the amino acids. Each amino acid is matched to a tRNA molecule carrying a specific anti-codon. A specific amino acid will be added only if it is recognized by its specific codon. Based on the triplet code, no codon recognizes ornithine, thus ornithine cannot integrate proteins primary structure.
26
If an amino acid isn't found in a protein that means it isnt able to form peptide bonds: T or F
F: If it is an amino acid it is capable of forming peptide bonds
27
If an enzyme assay like ornthinine decarboxylase assay is said to be highly specific, what does that mean? What does it measure? What does it not measure?
- They can distinguish their target enzyme activity from the many other enzymatic reactions in a cell
- That means it is highly specific to both the reactions it catalyzes and in their choice of substrates. Therefore, specific enzyme assays like ornithine decarboxylase assay are very specific and only measures the activity of a single chemical reaction catalyzed by ornithine decarboxylase.
- The essay measures the enzymes activity, NOT the quantity of substrate present in the cell
28
What is the molecule that enter the citric acid/ Kreb's/ TCA cycle?
Acetyl- CoA
29
If the lung cells of heavy smokers would be expected to have greatly increased concentrations of cP-450, then what would this mean for the levels of cP-450 DNA and mRNA present in the cell?
- cP-450 DNA is just present in the genome, so its levels do not change specifically in the lung cells
- The levels of cP-450 mRNA should be elevated in smokers as they are almost directly related to the levels of cP-450 protein produced to get rid of the toxins and would .: need the genes in the DNA from the genome of these cells to be expressed further .: resulting in increased mRNA sequences
30
Cells that are in what stage of the cell cycle are NOT actively dividing?
Interphase
31
Anaphase
Phase of mitosis where the sister chromatids are being separated
32
Metaphase
Phase of mitosis in which the chromosomes are locate din the middle of the cell plate
33
Do mature erythrocytes contain DNA?
No they have no nucleus and .: have no DNA
34
What are examples of proteins that regulate cell division?
Cyclins and maturation promoting factor (MPF)
35
Animal viruses are obligate parasites, meaning that......
Animal viruses can only infect animal cells
36
What is a telomere? What do they contain?
- Telomere refers to a distal end of a chromosome.
| - Telomeres contain non-coding repeats.
37
In general, telomeres are NOT important to bacterial cells because most bacterial chromosomes:
Are circular
38
How are nucleotides linked together in a single strand of DNA?
Nucleotides are linked to one another by phosphodiester bonds between the sugar base of one nucleotide (thymine) and the phosphate group of the adjacent nucleotide (adenine) in a way that the 5′ end bears a phosphate, and the 3′ end a hydroxyl group.
39
The flux of sodium into the cytoplasm of a cell results in what? This is required for?
- Membrane depolarization
| - Activation of action potentials
40
When does hyperpolarization occur?
When the membrane potential becomes more electronegative
41
When does repolarization occur? What causes it? Are sodium channels open during this time?
- Occurs after the membrane has been depolarized
- Is due to the opening of potassium channels.
- Sodium channels are typically closed during this period.
42
Chloride ions follow the movement of other ions?
Sodium ions
43
AAMC FL1 Q48 states that: Aldosterone is responsible for the conservation and elimination of which ions?
Conservation of sodium and elimination of potassium
44
The release is ACTH from the pituitary gland is regulated by what kind of feedback? What does this
-Negative feedba
45
Gluccocorticoids increase _______ ________, but suppress ______ _______, which is mediated by what?
-Increases protein degradation, but decreases immune function, which is mediated by white blood cells
46
Increased systemic vascular resistance, increased extracellular volume, and increased cardiac contractility can lead to what?
Hypertension
47
The most rapid rate of gluconeogenesis will most likely occur in the body when:
Gluconeogenesis becomes active when the body needs more glucose to generate energy .: It is likely to occur when glucose levels are low
48
What is gluconeogenesis?
Pathway for the synthesis of glucose (a carbohydrate) from other metabolic compounds such as lipids and amino acids.
49
Gluconeogenesis is increased by high levels of? What does this mean in terms of regulation?
- Cortisol?
| - That gluconeogenesis is most likely down regulated when cortisol is inhibited
50
What is meant by the fact that working skeletal muscles are insulin independent? How exercise affect this blood glucose levels for patients w diabetes?
- Working skeletal muscle can use glucose independently from insulin availability
- Exercise will be able to reduce the levels of glucose in both types of diabetes. (working skeletal muscle is being used more during exercise)
51
What is the endomembrane system responsible for?
It is the portion of the cells that is in charge of modifying proteins that will be secreted
52
Despite the effects of diabetes, the brains of diabetic patients still receive adequate nourishment. This is most likely because the brain:
Contains glucose transporter for the uptake of glucose that are insulin- independent
53
In diabetes mellitus, will use proteins and lipids as a source of glucose, thus increasing, rather than decreasing, leading to
- An increase in appetite
- Unexplained weight loss
- Feelings of fatigue
54
The kidneys can reabsorb glucose at what rate? If the levels of glucose in the body is too high for the kidneys to filter as is seen in diabetes patients, what can happen?
- 320mg/min
| - The levels of glucose in the filtrate that are in excess will pass into urine, leading to a sweet taste.
55
Glucose transporter proteins in the liver do not require the presence of insulin to facilitate the uptake of glucose. However, insulin does stimulate the first step in the glycolytic pathway within the liver. Therefore, in liver cells, insulin most likely:
- Aids glucose uptake by decreasing the cellular concentration of glucose.
- The question states that insulin stimulates the first step in the glycolytic pathway in the liver. This will result in a decrease of the cellular concentration of glucose. To compensate for the low cellular glucose concentration, glucose uptake is increased.
56
What is the mechanism that regulates the release of corticotropin releasing hormone (CRH) form the hypothalamus
Negative feedback
57
In normal conditions, high levels of circulating glucose and other stressors activate the production of
corticotropin- releasing hormone (CRH) from the hypothalamus
58
CRH will stimulate the pituitary gland to release of ______ which will trigger ________ release from the _________ _________
- ACTH
- Cortisol
- Adrenal cortex
59
High levels of circulating cortisol will inhibit _______ secretion (negative feedback)
CRH
60
High levels of circulating cortisol are the stimulus to reduce __________________________
secretion from the hypothalamus
corticotropin releasing hormone (CRH)
61
The gastrrointestinal epithelial cells are typically highly _____________
Proliferative
62
What do phosphodiester bonds link?
the 3ʹ carbon atom of one deoxyribose and the 5ʹ carbon atom of another deoxyribose within the DNA molecules AKA the sugar phosphate backbone of DNA
63
If H+ is a reactant in a rxn how could you manipulate pH to shift the reaction equilibrium to the right to form product?
You could decrease pH so that there would be more H+ ions present in solution. Increasing H+ concentration on the reactant side would shift the equilibrium to the right and favor product formation
64
Which AA contains sulfhydryl groups?
Cysteine (C)
65
If the ETC is shut down, what would be the major pathway for ATP production?
Glycolysis
66
What 3 main steps happens when a macrophage ingests foreign material?
1. The material initially becomes trapped in a phagosome.
2. The phagosome then fuses with a lysosome to form a phagolysosome.
3. Inside the phagolysosome, enzymes digest the foreign object.
67
What is allosteric inhibition vs competitive inhibition?
1. When an inhibitor inhibits enzyme activity by binding to a regulatory site other than the active site of the enzyme
2. In contrast, competitive inhibition involves competition for binding to the active site
68
If a cell contains a v high concentration of chlorine in comparison to outside the cell, how would it maintain this? What kind of transport would need to be used?
In order to maintain a higher concentration of chlorine ions inside the cell, the ions must be moved into the cell against their concentration gradient, which requires energy. This process is active transport
69
If potassium ion channels are blocked, how would this affect membrane repolarization and the length of an action potential?
If potassium ion channels are blocked, the membrane would fail to repolarize, extending the length of the action potential and simulating excessive muscle contractions.
70
Where are secretory proteins normally produced and folded?
The rough ER
71
Proteins w high isoelectric points (like 9) typically have what charge at physiological pH (7)?
+
72
What is the isoelectric point of a protein?
The pH of a solution at which the net charge of a protein becomes zero
73
What happens if the solution pH is above the pI of a protein?
The surface of the protein will become predominantly negatively charged
74
What happens if the solution pH is below the pI of a protein?
The surface of the protein will become predominantly positively charged
75
What happens if the solution pH = pI of a protein?
Protein is neutral or has a net charge 0
76
Proteins that are translocated into the nucleus usually contain a
Nuclear localization sequence
77
If a protein or enzyme activates transcription factors for the target genes of another kind of protein, what this protein or enzyme likely have? Why?
A nuclear localization sequence bc transcription factors are found in the nucleus, meaning the protein or enzyme must enter the nucleus to activate these transcription factors and in turn, these genes
78
What does ubiquitination do?
Targets a protein for degradation by a proteasome
79
If reducing agents separate subunits of a protein, what does this mean the tertiary structure of the protein was held tg by? Why?
1. Disulfide bonds, which implicate the thiol groups of cysteine residues
2. Disuflide bonds are broken upon reduction
80
If the insertion of a random transmem protein that the alters the permeability of the inner mem where to be inserted into the inner mem of the mitochondria, what would this cause?
The proton gradient across the inner membrane will dissipate
81
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes the reversible conversion of....
Glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate
82
Posttranslational modification of proteins such as histone acetylation can be analyzed by what kind of blot?
SNOW DROP: Western blot
83
Vasopressin regulates the insertion of aquaporins into the apical membranes of the epithelial cells of what renal structure?
Collecting duct
84
What are the primary myelin-forming cells in the peripheral nervous system?
Schwann Cells
85
What are the primary myelin-forming cells in the central nervous system?
Oligodendrocytes
86
What is the equation for osmotic pressure?
Π = iMRT
87
A prion is best described as an infectious ______? Why?
- Protein
- a prion is an abnormally folded protein that induces a normally folded version of the protein to also adopt the abnormal structure, which is often deleterious
88
Blood from the small intestine is first transported to what organ? What does this organ do?
Liver, which regulates nutrient distribution and removes toxins from the blood
89
Assume that a typer of bacteria immediately enters the bloodstream from the small intestine. What would be the first major organ that the blood-borne bacteria would encounter? Why?
Liver bc it regulates nutrient distribution and removes toxins from the blood
90
In order for a child to be homozygous for a recessive disease what must the parents have if neither of them actually have the disease?
The child would have to inherit the two recessive alleles from their parents (1 from each), meaning if neither of them actually have the disease, they'd have to be carriers of the disease and have at least one recessive allele to give to their child. If only parent carries the recessive allele, there is no way the child can come out homozygous recessive bc they would need 2 recessive alelles
91
What are neuromodulators vs releasing factors?
- Neuromodulators: Do not stimulate the release of a hormone on their own, but can modulate (enhance or inhibit) the responses of the secretory cells of the gland that originally releases it
- Releasing factors stimulate the release of the target protein on their own
92
Internalization of viral particles through endocytosis is mediated by what strucutre?
Endosomes
93
How do viruses enter host cells via endocytosis?
Through the fusion of the viral membrane with the host cell membrane.
94
Proteases function to
Digest proteins into smaller fragments
95
What end to amino acids get added to on a growing polypeptide chain?
The C terminus
96
PEP is product of
Glycolysis
97
How can you remember the reactants and productions of the citric acid/ krebs/ TCA cycle
```
Can: Citrate
I: Isocitrate
Keep: Alpha- ketoglutarate or alpha ketoglutaric acid
Selling: Succinyl CoA
Sex: Succinate
For: Fumarate
Money: Malate
```
98
Under anaerobic conditions how many moles of ATP are produced by glycolysis?
2 moles of ATP
99
Under anaerobic conditions, how many net molecules of ATP are produced by the consumption of 5 moles of glucose?
Under anaerobic conditions, 2 moles of ATP are produced from each mole of glucose. Thus, 10 moles of ATP would be generated from 5 moles of glucose. Since there are 6 × 1023 molecules per mole, 10 moles of ATP is equal to 6 × 1024 molecules.
100
How many individual molecules are there per 1 mole
1 mole= 6x10^23 molecules
101
The central nervous system is derived from what embryonic layer?
The ectoderm
102
The heart, kidneys, and skeletal muscle are derived from what embryonic layer
The mesoderm
103
Motor proteins move along what? Through interactions with what?
Motor proteins move along microfilaments through interaction with actin
104
Lysosomes are defined as
membrane-bound organelles that contain hydrolytic enzymes activated by a low pH
105
Microtubules are cellular structures that originate from
Centrosomes
106
cytotoxic T lymphocytes target virus-infected cells by
recognizing the viral antigen presented on the cell surface of the virus- infected cells
107
If something binds to the promoter on a gene, then regulation occurs at what level?
Transcriptional (affects mRNA synthesis), not translational,
108
What part of the antibody allows for recognition of a particular antigen? Where are the found
-The variable portion of the antibody which is typically found on the ends of the upper v section of the Y shaped antibody
109
Where in the human male reproductive system do the gametes become motile and capable of fertilization?
Epididymis
110
Are sperm produced in, mature in, and become motile in the same structure?
No: Sperm is produced in the seminiferous tubules of the testes and then completes maturation and becomes motile in the epididymis.
111
during normal muscle contraction, ATP is required to
break the bonds between the actin filament and the myosin head
112
According to the cross-bridge model of muscle contraction, the muscles stiffen after death because ATP is unavailable to bind and directly release:
the myosin head from the actin filament.
113
A homodimeric protein was found to migrate through SDS polyacrylamide gel electrophoresis (SDS-PAGE) with a mobility that matched that of a 45-kDa standard. What change in the experiment would increase the chances of observing the mobility expected for the 22.5-kDa monomer?
Adding a reducing agent: a reducing agent would eliminate any disulfide bridges and allow the monomers to run separately–thus leading to a migration expected for the 22.5-kDa protein.
114
What are the relative potentials for force and power generation by a slow-twitch muscle fiber and a fast-twitch muscle fiber of the same diameter?
The fast-twitch fiber is capable of generating more power than the slow-twitch fiber, while the potential for force generation is the same bc similarly sized fibers would generate similar force, regardless of fiber type (depends on cross- sectional area which is the same for muscle fibers of the same diameter)
115
Lack of oxygen shuts down what?
The Krebs cycle and the ETC bc the ETC only provides ATP aerobically
116
Work is the product of
force applied over a distance an object is moved
117
What do fast twitch fibers have a greater capacity for than slow- twitch fibers?
Greater Ca2+-pumping capacity
118
Slow twitch fibers are better adapted for what than fast twitch fibers? What do they have that allows them to do this?
slow-twitch fibers are adapted for aerobic exercise which suggests they are likely, relative to fast-twitch fibers, to have increased capillary density, larger numbers of mitochondria, and higher levels of oxygen-binding proteins
119
Pyrimidines
CUT the PY: C, U, and T
120
Purines
PUR As Gold: A, G
121
Convergent evolution is defined as
a process whereby distantly related organisms independently evolve similar traits to adapt to similar needs
122
gonadotropin-releasing hormone regulates
pituitary gonadotropin (luteinizing hormone and follicle-stimulating hormone) secretion
123
Kallman Syndrome is a disease in which gonadotropin-releasing hormone producing neurons fail to migrate from the olfactory area to the hypothalamus during embryonic development. Which endocrine axis is disrupted in individuals with Kallman Syndrome?
gonadotropin-releasing hormone regulates pituitary gonadotropin (luteinizing hormone and follicle-stimulating hormone) secretion. Thus, if gonadotropin-releasing hormone is not able to regulate luteinizing hormone and follicle-stimulating hormone secretion from the pituitary, the reproductive axis will remain quiescent.
124
an operon containing two genes in prokaryotic cells is transcribed from
a single promoter upstream of the first gene in the operon
125
In the heart, increased intracellular calcium levels will result in
enhancement of the contractile force of the heart.
126
The Na+K+ ATPase is an example of what kind of active transport
Primary
127
Primary vs secondary transport
Primary active transport uses a chemical energy source like ATP to move solutes against their concentration gradient. Secondary active transport, on the other hand, uses one electrochemical gradient to move different molecules against their own concentration gradients.
128
Histone acetylation typically
promotes transcription by modifying chromatin structure and loosening it
129
Fasting leads to what? Continued fasting them leads to what?
asting leads to glycogen breakdown and gluconeogenesis, then continued fasting leads to the production of ketone bodies by sustained fatty acid oxidation.
130
If βOHB is a component of ketone bodies, when are serum levels of βOHB elevated?
Serum levels of βOHB are elevated when there is sustained fatty acid oxidation.
131
The adrenal medulla is part of which branch(es) of the peripheral nervous system?
The sympathetic branch of the autonomic nervous system only because the adrenal medulla secretes epinephrine and norepinephrine in response to short-term stress. Reactions to short-term stress are mediated by the sympathetic branch of the autonomic nervous system.
132
Which of the following best describes the chemical energy that is derived from the Krebs cycle? Energy is produced in the forms of:
ATP, which directly supplies energy for many cellular processes, and NADH, which supplies energy for the electron transport chain. ->The answer to this question is C because the Krebs cycle produces both ATP and NADH but not NAD+. ATP directly supplies energy for many cellular processes, such as muscle contraction, and NADH, which is used in the electron transport chain.
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Osmotic pressure is directly proportional to
Solute concentration
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What is the equation for osmotic pressure?
Pi=inRT
135
During hypoxia, what is activated and what is attenuated? This leads to an increase in concentration of what? For glycolysis to proceed what must happen?
- glycolysis is activated while mitochondrial functions (oxidative phosphorylation) are attenuated.
- This metabolic reprogramming leads to increased concentration of NADH inside the cell.
- For glycolysis to proceed, NADH must be converted back to NAD+ through lactic fermentation
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Phosphoglucose isomerase is involved in what cellular process?
Glycolysis
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Why is tubulin often used as a loading control to ascertain an equal amount of protein loading in each lane in a Western blot analysis
tubulin, a cytoskeletal protein, is stable under most conditions, including hypoxia.
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A restriction enzyme that has a a four-base recognition sequence, a six-base recognition sequence, and an eight-base recognition sequence would cut base pairs:
Palindromic sequences, every 4, 6, and 8 base pairs
139
Succinate dehydrogenase is known as what complex in the ETC?
Complex II
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succinyl-CoA synthetase, which results in
the increased production of succinate
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Imprinted genes are expressed in what manner?
in a parent-specific manner
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During protein synthesis, new amino acids are added to which terminal?
C- terminal
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Certain viruses contain RNA as their genetic material. One of the ways these RNA viruses replicate themselves is to:
code for or carry a transcriptase that copies viral RNA:RNA viruses require a type of transcriptase (reverse transcriptase) to replicate themselves
144
Large amounts of protein are found in the urine of a patient. Based on this information, which portion of the nephron is most likely malfunctioning?
Glomerulus: In healthy individuals, the structure of the glomerular capillaries prevents the entry of large molecules, such as proteins, into the filtrate.
145
While the optimum pH value varies greatly from one enzyme to another, the optimum temperature for enzymes is normally what
37 degrees celsius
146
What is an action that SSRIs block? What this increase?
-transport of released serotonin back into the presynaptic terminal AKA they block reuptake
by blocking serotonin reuptake in the presynaptic neuron.
-Blocking the reuptake of serotonin into the presynaptic neurons would increase the amount of time that serotonin is available in the synaptic cleft to bind to postsynaptic neurons.
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antidepressant drugs act to increase the amount of serotonin in the synaptic space. Therefore, the action of serotonin on postsynaptic receptors would be terminated by
the removal of serotonin from the synaptic space.
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What happens with osmotic pressure and fluid movement in blood if there are too many particles/ plasma proteins? What about too little like what happens during malnutrition?
- Too many plasma proteins: Osmotic pressure increase, fluid enters the blood/ circulatory system too "dilute" the solutes .: increasing blood pressure
- Too little plasma proteins: Osmoitc pressure would decrease and fluid would leave the blood/circulatory system AKA enter the body tissues to account for the higher concentration of solutes out of the blood vessel .: blood pressure decreases
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Osteoblast vs osteoclast
osteoblasts function to build and repair bone, osteoclasts break down bone.
150
If we wanted to increase calcium levels in the blood, would we want to increase osteoblast or osteoclast activity?
osteoblast activity should be decreased and osteoclast activity should be increased to release stored calcium from the bone to the bloodstream
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In what order does the filtrate pass through the tubular regions of the nephron?
1. Bowman's capsule
2. Proximal tubule
3. Loop of Henle
4. Distal tubule
5. Collecting duct
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P450 acts as what? What does it do?
monooxygenases, where an oxygen atom is inserted into a substrate (the drug of interest), thereby resulting in the oxidation of the substrate. and reduction of the oxygen
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What happens during the phoshporylation of tyrosine?
Tyrosine has a nucleophilic hydroxyl group that attacks the terminal phosphate group (γ-PO32–) on ATP, resulting in the exchange of the hydrogen atom of a hydroxyl group for a phosphate group of ATP.
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A defining characteristic of proteins that act as transcription factors is? What is not?
- The defining characteristic of a transcription factor is that it has a DNA-binding domain that allows it to bind to regulatory nucleic acid sequences in a gene to alter transcription.
- The fact that they are present in the nucleus:Transcription factors ultimately end up in the nucleus, but other proteins can exist within the nucleus that do not alter transcription.
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Where does fatty acid oxidation occur?
In the mitochondria
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What does the carnitine shuttle do?
transports fatty acids into the mitochondria for oxidization.
157
What does a carboxylase do?
Adds carboxyl groups
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How much ATP is consumed/ produced during the preparatory and payoff phases of glycolysis, respectively?
Two ATP molecules consumed, four ATP molecules produced
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In what steps is ATP consumed in glycolysis?
In the prepatory phase where glucose is converted to glucose-6-phosphate, and fructose-6-phosphate is converted to fructose 1,6-biphosphate.
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In what steps is ATP produced in glycolysis?
The first two ATP molecules are produced in the conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, and another two ATP molecules are produced in the conversion of phosphoenolpyruvate to pyruvate.
161
As blood passes through actively contracting skeletal muscle tissue, the affinity of hemoglobin for oxygen in the muscle tissue:
decreases as a result of a decrease in plasma pH. -> Affinity would decrease with a decrease in plasma pH, and during prolonged exercise, anaerobic respiration would decrease the plasma pH due to the build up of lactic acid ALSO bc of the decrease in PO2 of actively contracting muscle
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Henry's law
Henry’s Law constant kH relates the solubility of a gas S to the pressure of that gas Pg above the solution and is written as S = kH•Pg.
163
Where is ghrelin secreted from? The small intestine, stomach, or hypothalamus?
Small intestine and hypothalamus
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how many nucleotides code for an amino acid?
3
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When trying to determine the number of nucleotides that codes for x amino acid long sequence, what must you remember to do?
Add the triplet that codes for the STOP codon
166
As blood glucose levels increase after a meal, levels of what will decrease?
Glucagon
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Because of a feedback mechanism, the levels of circulating ghrelin are
the opposite of the amount of weight gained. They are low when the individual gains weight (person has more energy stores when heavier) and high when the individual loses weight.
168
In what order does tRNA move on the ribosome?
A-> P-> E: During protein translation, aminoacyl transferase functions to transfer the tRNA originally bound at the A (amino acid) site to the P (peptide) site and later to the E (exit) site of the ribosome.
169
From which sites on the ribosome is the amino acid on the tRNA added to the growing peptide chain?
As it moves from the A site to the P site
170
RT-PCR is a molecular technique that measures
mRNA levels of specific protein.
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Southern blot is a technique that analyzes what? Can it be used to measure the transcriptional regulation of a gene?
- genomic DNA
| - no
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Quantitative PCR is a technique that measures what? Can it be used to measure the transcriptional regulation of a gene?
the levels of DNA, not mRNA
| -No
173
Western blot is a technique that measures the
the translational levels of a protein,
174
Native PAGE separates
molecules based on their electrophoretic mobility, relying on length, conformation, and charge.
175
Gel filtration chromatography separates protein only on
the basis of their size.
176
The inactivate X chromosome is one of the last
chromosomes to replicate.
177
Both the active and inactive X chromosome
Replicate
178
A negative control is the one that is performed in the conditions that
are not expected to give positive results.
179
Extra water is normally excreted through what organs?
Extra water is normally excreted through skin and lungs. The skin excretes water through the process of transpiration, and the lungs use water to humidify the air that enters the body.
180
The osmolarity of urine in these subjects was 958 milliosmoles/L, compared with an average blood osmolarity of 284 milliosmoles/L. The higher osmolarity of urine suggests that:
the kidneys are acting to conserve water: An increase in water conservation would result in higher urine osmolarity and lower blood osmolarity.
181
If someone was dehydrated, the osmolarity bt the blood and urine would be?
Closer
182
What activates osmoreceptors? What does this process trigger?
Osmoreceptors are activated by the increase in osmolarity of the blood. This process triggers the sensation of thirst.
183
heart rate is
the number of heart contractions per minute.
184
What is stroke volume? What happens to it during dehydration?
The stroke volume is the amount of blood that is pumped by the left ventricle per beat. In dehydration conditions a decrease in stroke volume will decrease, the cardiac output.
185
During exercise, muscles produce ______ that goes into circulation. What will this do to the osmolarity of venous blood?
During exercise, muscles produce lactate that goes into circulation. The presence of lactate will increase the osmolarity of the venous blood.
186
The Na+/K+ ATPase, or sodium/potassium pump is an active transporter that pumps sodium and potassium ions through the membrane _______their concentration gradient to maintain osmotic pressure.
Against
187
When adding negatively charged groups to a protein, we are decreasing its
Isoelectric point
188
Microglia are
phagocytotic innate immune cells specific to the brain.
189
In the brain, B cells, Cytotoxic T cells, and Helper T cells are all
adaptive immune system cells and require activation by microglia in order to mount an immune response
190
Tight junctions are
intercellular junctions that prevent the movement of solutes within the space between adjacent cells.
191
How do tight junctions work in the blood- brain barrier?
In blood capillaries, neighboring endothelial cells form tight junctions with one another to restrict the diffusion of harmful substances and large molecules into the interstitial fluid surrounding the brain.
192
An amber codon is a
stop codon
193
Endosomes are formed to
transport a substance from the outside of the cell,
194
Receptors destined for the cell mem will be
synthesized in the RER, modified in the Golgi apparatus, and transported to the membrane by transport vesicles.
195
What is a test cross used for?
to identify if an organism that shows a dominant phenotype is a homozygous or heterozygous.
196
How do you perform a test cross?
Cross the organism w the dominant phenotype (heterozygous or homozygous dominant) w a homozygous recessive phenotype
197
If the opening of GABA receptors results in entry of chloride ions inside the cell, as chloride ions the cell membrane would become?
Hyperpolarized: As chloride ions have a negative charge, the entry of chloride ions into the cell will make the cytoplasm more negative thus hyperpolarizing the cell membrane.
