Alex - BIO - Flashcards
1
Q
Select all of the following that constitute differences between prok and euk translation
A
Initiator tRNA is bound to Met in euk and “formyl-met” in prok
2
Q
He accidentally adds a lysine-rich protein to the pH-gradient gel instead of his desired sample, which was largely composed of hydrophobic residues. How would this impact the findings?
A
Adding Lysine will make it more + and move closer to cathode (which is negative in electrophoresis)
3
Q
Where are fatty acids broken down and how many membranes must they diffuse through to get there?
A
Fatty acids are broken down in the mitochondria and must diffuse through by the cell membrane and mitochondrial membrane
4
Q
What is a phospholipid?
A
A phospholipid is covalently bound to two fatty acids and a phosphate group
5
Q
What is the difference between LDL and HDL?
A
LDL is the major transporter of cholesterol to body tissues. HDL brings cholesterol to the liver, chylomicrons and VLDL primarily transport tryglycerides.
6
Q
What is the function of chaperone proteins?
A
Lipids, sugars, and phosphates are all regularly added to proteins. Chaperone proteins help guide, NOT ADDED
7
Q
What is the function of the nucleolus?
A
Nucleolus assembles ribosomes
8
Q
What is the function of the large intestine?
A
Large intestine reabsorbs water using ion transport
9
Q
If a person is laying supine (lying face upward), is their blood pressure the same as standing or sitting up?
A
If the body is in a supine position, blood pools in the veins and results in a higher blood pressure
10
Q
Where is calcitonin made? What is its function?
A
Calcitonin is released from the hypothalamus. It reduces blood Ca+ levels by inhibiting osteoclast activity.
11
Q
Do muscles use Ca+ for mechanical responses?
A
Muscle activation requires the release of calcium from the sarcoplasmic reticulum to cause a mechanical response in muscles.
12
Q
Passage analysis. Read passage more carefully if it is complex.
A
Passage analysis. Read passage more carefully if it is complex.
13
Q
What happens to human cells if of ocean water is consumed?
A
Got the question right. Ocean water is very concentrated and makes human cells in a surrounding hypertonic solution, so water flows out of cells.
14
Q
What kind of bonds are peptide bonds?
A
Peptide bonds are amide bonds, between an amine group and carboxylic group. They exhibit resonance stabilization.
15
Q
Be careful with true statements.
A
Make sure the answer answers the question. The answer I picked was just a true statement.
16
Q
What is DNA hybridization?
A
Hybridization describes the bonding of complimentary nucleotides
17
Q
What is the most likely decision for using this compound in the experiment?
A
For these questions pick the answer choice that HAS to be true and proves why the compound has to be there
18
Q
If this amino acid is similar to the one described in the passage (S156E) and is often phosphorylated, which of these is likely to be that phosphorylated protein?
A
Serine, Threonine, and Tyrosine are the amino acids most prone to phosphorylation.
19
Q
Make sure to read each answer choice before choosing
A
Did not read the answer I picked fully. Went too fast.
20
Q
What is the most effective method of sterilization?
A
An autoclave is the most effective sterilizing technique used in the lab. It heats to 120 C and puts it under 2 atm. Kills almost anything.
21
Q
Which of the following describe the difference between single and double crossover events?
A
A double crossover event is when chromosomal arms of homologous chromosomes cross over in 2 different places along the arm and can involve segments in the middle of the chromosome arms. A single crossover event only affects the ends of the chromosome arms.
22
Q
Which of the following muscle types uses the troponin complex?
A
Troponin is used in muscle contraction in skeletal and cardiac muscle. It is NOT used in smooth muscle.
23
Q
At physiological pH, what is the charge of a peptide bond?
A
Peptide bonds are not ionized at physiological pH. They do possess double bond character.
24
Q
Injection of insulin into the bloodstream it LEAST likely to result in which of the following?
A
Insulin functions to promote the buildup of large molecules for energy storage in the body and to stop the body from breaking down molecules for energy.
25
Which of the following is most likely NOT a result of a fatty acid catabolizing enzyme deficiency?
Dysfunction of an enzyme that catabolizes fatty acids will unlikely NOT cause hyperglycemia, because the body is relying more heavily on glucose for energy so blood glucose levels would be low
26
Which of the following samples has to be single stranded DNA and can not be double stranded?
A DNA strand with X% A, X% T and Y% C, Y% G could be single stranded, but it is also possible to be double stranded.
27
Those species that are capable of both sexual and asexual reproduction will typically prefer sexual reproduction because?
Sexual reproduction increases the variation in the next generation. We cannot say it increases the likelihood of survival for each individual
28
PET scans follow the movement of a radiolabeled compound as it travels throughout the body. Which compound can be labeled to detect metabolic activity in cancer cells?
Radiolabeled glucose is better because it travels throughout the entire body. Not passage analysis, look at the big picture.
29
Which aspect of this compound presents the biggest obstacle to its use as a cancer drug?
A nonpolar compound with multiple hydrocarbon groups, electron delocalization through rings, and no charge means it is poorly soluble in water. So it has low solubility in a hydrophilic media
30
Compare the answer with the question before moving on.
Compare the answer with the question before moving on.
31
What is the effect of cholesterol?
Cholesterol increases membrane rigidty by attracting adjacent phospholipid tails.
32
Which of the following do not have proteins with a nuclear localization signal?
E Coli and archaea do not have nuclei and do not need a nuclear localization signal. Fungi are eukaryotic and use nuclear localization signals.
33
Which of these describe a pair of analogous and homologous structures?
Analogous structures are those that evolved independently to carry out same functions ( wing of bee, wing of bird). Homologous structures are those that have a similar evolutionary history and arise from the same source, with different functions.
34
Where do protons flow in the ETC, in protein complexes and at the end?
Protein complexes in ETC push protons from the matrix into the IM space. This establishes the proton gradient. During ATP regeneration, H+ ions flow from IM space back to the matrix via ATP synthase.
35
What substrates can undergo gluconeogenesis?
Gluconeogenesis can use oxaloacetate, pyruvate, and alanine. It cannot use acetyl Co-A
36
What are lacteals?
The lacteals are in the intestines and are associated with absorbing fat into the lymphatic system
37
Read the question carefully before finding numbers for calculations
Read the question carefully before finding numbers for calculations
38
Passagea analysis
Passagea analysis
39
If stuck, go back to the beginning of the passage and eliminate answer choices that do not agree with the main argument
If stuck, go back to the beginning of the passage and eliminate answer choices that do not agree with the main argument
40
If a researcher wants to halt cell growth before replicaiton, which phase should they be frozen in?
To halt cells before replicaiton, stop division in Interphase, which occurs between rounds of divisions.
41
Researchers noted that when a Lysine residue on a histone is acetylated, its side chain becomes more neutral. Which of the following conclusions would reasearchers most likely reach?
DNA is negatively charged, and Lysine residues n histone allow for tight histone-DNA interactions. Acetylation of Lysine makes it positive, and therefore looser interactions with DNA. This creates looser chromatin called euchromatin. Deacetylation results in restored positive charge which promotes euchromatin. Heterochromatin is tight, denser chromatin.
42
Based on the passage, compared to T11, residue T3 is likely:
A residue called "T3) means a threonine group at position 3. The N-Terminus is the beginning of the polypeptide chain, so position 3 is closer to the N-terminus than position 4. The N-terminus is likely to be positively charged in vivo. The C-terminus is likely negatively charged in vivo.
43
Where are post transcriptional mods made?
Post-transcriptional modifications are made entirely within the nucleus. They involve addition/removal of the substrate and are catalyzed by enzymes
44
What charge are amino acids at in physiological pH?
At physiological pH, all free amino acids will have at least one negative and positive charge, due to the N-terminus and C-terminus.
45
Arachidonic acid is not a precursor for which class of molecules?
The compound from the study is degraded into arachidonic acid and ethanolamine. Ethanolamine can be used in phospholipids, thromboxanes, and prostaglandins. Catecholamines are derived from Tyrosine and would not be derived from arachidonic acid.
46
What happens to a mixture if two competitive inhibitors are mixed together and added? (one inhibitor is a strong base, the other is a strong acid)
If one competitive inhibitor is a strong acid and another is a strong base, if they are mixed before being exposed to the reaction mixture then they will neutralize each other and nothing happens.
47
Count the elements present in the answer choice and make sure it matches with the calculation
Count the elements present in the answer choice and make sure it matches with the calculation
48
What happens in mitosis and meiosis? Which stages are haploid and which are diploid?
During Mitosis and Meiosis II, sister chromatids are separated to form 2 diploid daughter cells. Meiosis I separates homologous chromosomes to create haploid daughter cells. These divide again by separating sister chromatids in Meiosis II to form 2 haploid cells.
49
Phylogenetic trees
Phylogenetic trees
50
Be careful with true statements
Be careful with true statements
51
What is the function of gap junctions?
Gap junctions connect cytoskeletons
52
Are synaptic neurons faster than reflex neurons?
Chemical synapses and neurons that use them are slower than reflex neurons that use electrical synapses
53
What is hyperglycemia and its effects on the body?
In severe hyperglycemia, insulin cannot effectively uptake glucose. This leads to glucose and ketone bodies found in the urine. In extended hyperglycemia, the body relies on fat metabolism for energy, which produces ketone bodies.
54
What is the ploidy of mitosis and meiosis daughter cells?
Meiosis I results in 2 haploid cells with 23 chromosomes, each consisting of 2 sister chromatids. Mitosis results in diploid daughter cells, meiosis results in haploid daughter cells.
55
What is the difference between northern, southern, and western blots?
Western blots give info about proteins, Northern blots give info about RNA, Southern blots give info about DNA.
56
What is the effect of a competitive inhibitor on a lineweaver-burk plot?
In a Lineweaver-Burk plot, x intercept = -1/Km while the y intercept = 1/Vmax. In competitive inhibitors, Km increases. So the x intercept should move closer to the x axis since -1/Km increases as the x intercept approaches the x axis.
57
What kind of molecules does the blood brain barrier block?
The blood brain barrier protects the brain against "large and polar agents", according to the passage. CO2 is small and nonpolar, so it can freely pass the barrier.
58
What effect does replacing OH groups with acetyl groups have on a molecule?
Replacing OH groups with acetly groups (O=RC-CH3) makes it more lipophilic.
59
What does the ectoderm give rise to? What does the mesoderm give rise to? What does the endoderm give rise to?
The nervous system is derived from the ectoderm. The ectoderm gives rise to the nervous system, epidermis, and lining of mouth anus and nostrils. The mesoderm gives rise to structures inside the body like musculature, connective tissue, gonads, and kidneys. The endoderm gives rise to interior linings of the body like the GI, lungs, liver, and bladder.
60
What is the function of the golgi apparatus?
The golgi apparatus packages proteins in vesicles for transport to other parts of the cell. It targets proteins for excretion. It produces Lysosomes.
61
What makes up eukaryotic flagella?
Microtubules are observed in eukaryotic flagella.
62
What are lipid rafts and what composes them?
Lipid rafts surround transmembrane proteins and serve signaling purposes. They are composed of long, saturated lipids that strongly adhere to each other and their associated protein.
63
Where are phospholipids and lipids synthesized?
Phospholipids and lipds are synthesized at the surface of the smooth ER before being packaged into vesicles and delivered to the plasma membrane or stored in the cell for future use
64
What effect do unsaturated and saturated fats have on the cell membrane?
Unsaturated fats are more flexible due to the "kinks" in their chain from the double bonds. They add fluidity to the membrane. Saturated fats add rigidity to the membrane. Cholesterol stabilizes membranes: it makes the membrane more fluid at low temperatures and less fluid at high temperatures.
65
What is the difference between cis/trans and E/Z notations?
Cis/Trans notation is for simple alkenes. E/Z is for more complicated molecules. Z means the highest priority substituents are on the same side ("zee zame side").
66
Make sure to take the time to understand the graphs and what they represent.
Make sure to take the time to understand the graphs and what they represent.
67
If a downstream protein is abnormally delayed, at what point does the experiment show you the defect?
The initiation of differentiation refers to when the downstream first becomes active. So once that one protein's levels increase, you can start to detect abnormalities in the process.
68
A disease is X-linked. What is the probability that the daughter of an unaffected father and carrier mother is affected by the disease?
A daughter with an unaffected father and carrier mother has a 0% chance of being affected. Since the mom only has one copy and the father has zero copies, she cannot be affected.
69
Glucagon is released by the pancreas as a response to low blood glucose levels. It increases glycogenolysis to increase blood glucose. Glycogen is stored in the liver, so most of glucagon's action occurs in the liver.
Glucagon is released by the pancreas as a response to low blood glucose levels. It increases glycogenolysis to increase blood glucose. Glycogen is stored in the liver, so most of glucagon's action occurs in the liver.
70
What are the effects of hyperventilation? Make sure to know the blood O2 and CO2 levels
Hyperventilation results in net exhalation of CO2, increased blood pH, and increased hemoglobin affinity for O2. During hyperventilation, there is an increase in blood O2 and decrease in CO2. Hypoxia would not occur, because the body is not oxygen deprived
71
What is an organic acid?
Organic acids must have both carbon and hydrogen. They must have at least one hydrogen group bound to a carbon.
72
Hyperaldosteronism causes what?
Aldosterone increases H2O and Na reabsorption in the kidney, while exchanging K for Na ions. Aldosterone is released when blood K rises or blood Na falls. Aldosterone's effects include increased K secretion and Na reabsorption. It will also inhibit renin production via feedback inhibition.
73
What is the difference between lytic and lysogenic?
Lysogenic viruses use mitosis to pass viral DNA to daughter cells. Lytic viruses produce a large number of viruses within a cell that escape it and go infect other cells. A virus can be both lytic and lysogenic.
74
Trap question. Looked at the wrong graph. Make sure to compare the compounds in question and refer to the correct graph.
Trap question. Looked at the wrong graph. Make sure to compare the compounds in question and refer to the correct graph.
75
In a question that asks about the effects of manipulating a variable in an equation, make sure to get the answer choice picked, go back to the equation, and plug in the answer choice value to see if it yields the correct result/answer
In a question that asks about the effects of manipulating a variable in an equation, make sure to get the answer choice picked, go back to the equation, and plug in the answer choice value to see if it yields the correct result/answer
76
What is the order of the michaelis-mentin reaction at low substrate and high substrate concentrations?
At very low initial substrate concentrations, the michaelis-mentin reaction is approximately first order (the initial rise in the graph). As it flattens out, it becomes zero order.
77
Why are viruses unique?
Viruses are unique because they are in a gray area between living and non-living organisms.
78
Make sure to use the correct numbers from charts for any calculations
Make sure to use the correct numbers from charts for any calculations
79
Thiokinase converts fatty acids into their CoA derivatives. Next, the CoA derivatives are transported through the mitochondrial membrane bu carnitine. Where is thiokinase likely located?
If an enzyme acts on a fatty acid after it enters the cell but before it is transported into the mitochondria, it must be located on the face of the outer mitochondrial membrane.
80
If stuck on a question, compare complete guess to the passage before moving on
If stuck on a question, compare complete guess to the passage before moving on
81
Compare Thymine and Uracil's molecular structures.
Thymine is identical to Uracil but has an extra methyl group
82
What type of solvent would favor an SN2 reaction?
Polar aprotic solvents favor SN2
83
Compare guesses to the graph before moving on
Compare guesses to the graph before moving on
84
An immunoglobin would most directly involve which eukaryotic strucure?
Ribosomes regulate the translation and production of gene products. The nucleolus is the nuclear subdomain that assembles ribosomal subunits.
85
What types of amino acids would compose a transmembrane protein?
A transmembrane protein domain would be in contact with the nonpolar tails of the phospholipid molecules in the membrane, so nonpolar amino acids would likely make up parts of this domain
86
Make sure to read questions about graphs carefully
Make sure to read questions about graphs carefully
87
A DNA viral vector was most likely which kind of virus?
DNA viral vectors must come from DNA viruses. Retroviruses use positive-sense RNA genomes, not DNA genomes.
88
What is cell differentiation mediated by?
Cell differentiation occus primarily through different gene expression levels
89
What is involved in cell movement?
Flagella and cilia are involved in simple prokaryotic and eukaryotic cell propulsion. Actin polymerization near the edge of the cell membrane is responsible for cellular motility. Microtubule depolymerization is involved in mitosis, not movement
90
Which stages of mitosis and/or meiosis involve separation of homologous chromosomes?
Anaphase of meiosis I
91
What is genetic drift?
Genetic drift is the change in allele frequencies due to random processes. It can cause some alleles to not be passed down at all or cause others to be fixed as the only alleles present at that locus. It does not introduce new alleles or increase diversity
92
What is the difference between disruptive and directional selection?
Disruptive selection involves the extreme phenotypes being evolutionarily favored. Directional selection favors either of the extremes, but not both.
93
What is the difference between convergent and parallel evolution?
Convergent evolution is when entirely separate separate lineages gradually appear more similar over time. Example: birds, bats, and butterflies all developed wings to utilize the advantages of flying. Parallel evolution occurs when closely related species evolve in a similar way over time (and they were not similar beforehand).
94
What type of people are more likely to have X-linked recessive diseases?
Males because they only need to inherit one recessive copy of the gene to have the disease
95
How many distinct codons will code for amino acids within a protein?
There are 4 possible RNA bases, so there are 4^3 possibilities. This is a total of 64 possibilities, but subtracting for the 3 stop codons makes 61.
96
What type of bonds form secondary structures?
Hydrogen bonds between the backbone amide and carbonyl groups.
97
1% of a population has a recessive phenotype. What is the allele frequency for this recessive allele?
r^2 = 0.01. So the frequency is sqrt(0.01) which is 0.10, which is 10%.
98
What would happen to NADH levels and O2 consumption of cancer cells that are exposed to an inhibitor that inhibits respiration?
O2 consumption decreases with decreased ETC activity. NADH increases because the mitochondria are not oxidizing NADH in the ETC, which causes a buildup of NADH.
99
On a hemoglobin saturation curve, a right sided shift signifies what?
A right sided shift signifies decreased affinity for oxygen. 2,3-BPG also shifts the graph right. Low pH also decreases the O2 affinity and shifts the graph right.
100
Make sure the conclusion of the study is not too extreme or out of scope
Make sure the conclusion of the study is not too extreme or out of scope
101
What is the difference between cadherin protein and integrin protein?
Cadherin proteins are transmembrane proteins that play a role in cell-cell adhesion. Integrins are transmembrane receptors that modulate cell-extracellular matrix interactions. They often attach the cell to collagen and fibronectin fibers. Cadherin proteins do NOT form interactions with the extracellular matrix proteins.
102
Make sure to identify which axis contains the different experimental groups/conditions and interpret the data based on that.
Make sure to identify which axis contains the different experimental groups/conditions and interpret the data based on that.
103
What effects would a drug have that mimics the antagonist of Calcitonin?
The antagonist of Calcitonin is PTH. This increases blood Ca2+ concentration by increasing osteoclast activity and decreasing osteoblast activity.
104
What is the difference between the relative and absolute refractory periods?
The absolute refractory period lasts nearly the entire duration of the action potential, during which a second action potential cannot be started. V-gated Na channels are "inactivated" and the gate is closed. The relative refractory period is during the hyperpolarization phase. This is when Na channels are "de-inactivated": the inactivation gate is open but the activation gate is closed. A stimulus could theoretically produce another AP but the stimulus must be larger than usual. At this point, Na channels are de-inactivated and K channels are still activated (because K is still flowing out of the cell to finish the AP).
105
Where is sperm produced?
Sperm is produced in the Sertoli cells of the seminiferous tubules.
106
Do Bacteria have any protection outside of their cell envelope?
Bacteria have capsules that can protect it from foreign objects.
107
What is commensalism?
Commensalism is when one species benefits from the relationship but the other species is neither helped nor harmed from it.
108
If a drug was administered that irreversibly locked up calcium channels to be open, what would happen?
High calcium concentrations allow muscle contraction to take place. Tropomyosin would stop blocking the myosin binding site and the muscle would be unable to stop contracting, or be in constant tetanus.
109
What is ETC complex 2 and when is it activated?
Succinate dehydrogenase, which participates in both the citric acid cycle and the ETC. It takes electrons from FADH2 to reduce ubiquinone and in the ETC it metabolizes succinate to fumurate. It is active before complex 1.
110
What are the stages of zygote development?
Morula, Blastula, Gas, Neurulation. ("More Blasting Gas, I'm Nervous")
111
If the concentration of a protein in the blood is increased, is there more pre or post transcriptional control being done?
Post transcriptional control because the amount of translated protein is increased (assuming the amount of pre-mRNA is constant)
112
In isoelectric focusing, a protein moves closer to the cathode than the control protein. Extra amounts of what types of residues would cause this?
In isoelectric focusing, the cathode is negatively charged. Proteins that migrated farther have more positively charged residues.
113
An agar plate of growing bacteria becomes contaminated. The next morning, the contaminated area was clear. The contaminant was a? Virus in the lytic phase, Virus in the lysogenic phase, Distilled water, or a nutrient broth lacking the essential nutrients it needs to grow
Virus in the lytic phase, because the bacteria are prevented from growing.
114
If only one primer is added to a PCR mixture, what is the outcome?
The primer binds to one strand and replication is initiated in this strand. Only this one strand is replicated and replication is linearly amplified.
115
What does mature mRNA consist of?
Mature mRNA consists of a 5' cap (1 base), the Untranslated regions, and the 3' Poly A tail.
116
Rank the following structures from least to most compact: Euchromatin, Heterochromatin, DNA helix
DNA helix < Heterochromatin < Euchromatin
117
Where are intermediate filaments used?
Intermediate filaments primarily compose structural elements of skin. Keratin is made from intermediate filaments.
118
The frequency of an allele on the X chromosome is 8%. What is the frequency of the allele in men and women?
Males only need 1 copy of the allele, so their frequency is 8%. Females need 2 copes, so their frequency is 0.08^2 = 0.0064 or 0.64%.
119
If a protein is at a pH below its isoelectric point, what will the charge be?
Positive because the N terminus is positively charged. Above its pI, it is negatively charged because the C terminus is negative and deprotonated
120
A protein is neutral. If both Aspartic acid (pKa = 4) and Lysine (pKa = 10) are added to the protein, what effect will it have on the overall isoelectric point?
Aspartic acid and Lysine will have opposing effects on the overall pI. (10 + 4 + 2 + 9) / 4 = 8.
121
What is the isoelectric point of alanine?
5.5. Add up the side chain pKa's (2 and 9), which results in 5.5.
122
The author supports a theory that proposes decreasing virulence by attacking bacterial populations as a whole, not only the weaklings. If another effect of the drug killed bacteria least prone to virulence, what effect would it have on the drug's viability? (What is virulence?)
Virulence is severity or harmfulness of a disease. By killing the less virulent bacteria, there would be a negative effect because the population becomes steadily more virulent as the proportion of virulent bacteria still grows (antibiotic resistance)
123
2 separate antibiotic drugs work by disrupting cell signaling and the other lyses the cell membrane. Would these drugs work against viruses?
Neither would work because viruses are acellular and do not use cellular signaling. They can not be destroyed by cell membrane lysing. Also, the drugs apply to bacteria, not viruses.
124
Make sure to understand how the disease works and the genetic differences between the affected people and normal people
Make sure to understand how the disease works and the genetic differences between the affected people and normal people
125
Would an oxidant or reductant be more likely to reverse a disulfide linkage?
A reductant will reduce a disulfide linkage and therefore reverse (disrupt) it; oxidants create the linkages.
126
What is the pathway of a protein that is about to be translated?
A protein is translated by an ER-bound ribosome. Then it enters the ER for processing. Then it is sent to the Golgi for packaging. It is then exported through the plasma membrane.
127
Protein sequencing and Western Blotting on a mutant and a wild type protein produce near identical results. What kind of mutation likely happened?
A missense mutation. It cannot be a silent mutation because it is a mutant and there is a distinguishable difference between the two.
128
What is the difference between monocistronic and polycistronic?
Monocistronic (eukaryotic) mRNA have coding sequences for a single polypeptide, while polycistronic (prokaryotic) mRNA carries several open reading frames, creating multiple polypeptides from the same mRNA strand
129
What kind of receptors would likely respond to glutamate?
Glutamate is the most common excitatory neurotransmitter in the brain. It would stimulate excitatory receptors
130
The coding strand of a piece of DNA is 5' AGC. What would the primer be if researchers wanted to do reverse transcription PCR amplification?
5' AGC. PCR uses DNA primers, so cross out answers with uracil. The strand given is the coding (sense) strand, not the template strand. The mRNA produced has the same sequence as the coding strand, with uracil. mRNA for this would be 5' AGC with uracil. Now, this mRNA will be reverse-transcribed into complimentary DNA, so the cDNA is 3'TCG. But, the primer would be complimentary to this sequence so it is 5' AGC.
131
If the question gives new information about a sample that undergoes the same experiment and asks about the results, make sure the answer choices do not directly contradict the new information.
If the question gives new information about a sample that undergoes the same experiment and asks about the results, make sure the answer choices do not directly contradict the new information.
132
What direction to DNA polymerases read?
They read the parental nucleotide template in the direction of 3' -> 5', adding nucleotides to the growing strand in the 5' -> 3' direction.
133
Make sure to read graphs and charts carefully and compare to the passage to understand it fully before going to the questions
Make sure to read graphs and charts carefully and compare to the passage to understand it fully before going to the questions
134
Make sure to read graphs and charts carefully and compare to the passage to understand it fully before going to the questions
Make sure to read graphs and charts carefully and compare to the passage to understand it fully before going to the questions
135
A ligand is found to bind with a very large Kd (dissociation constant). Does that imply favorable or unfavorable interactions?
They are unfavorable interactions. Ka (association constant) and Kd(dissociation constant) are also ways to measure affinity, similar to Km but not the same. Ka = ES/(E)(S) and Kd is the inverse (E)(S)/ES. A higher Kd implies less favorable interactions.
136
What is an enol?
An enol is a structure with an C-OH group and an adjacent C=C, instead of a C=O bond and adjacent C-C bond as in a ketone.
137
The binding of a molecule is entropically unfavorable. What would likely be observed in the number of tautomeric forms between the bound and unbound structures?
Binding is entropically unfavorable. The unbound form exists in multiple tautomeric forms, while the bound form exists in only one form. This represents a decrease in entropy, since the number of forms that can exist goes from multiple to one. There is an overall increase in system order.
138
Is homologous recombination a form of proofreading?
Yes
139
What is the function of macrophages? What is opsonization?
Antigen presentation, phagocytosis, and cytokine release (a signaling molecule). Opsonization is the process by which antibodies bind to and recognize antigens on the surface of a pathogen. They then attract the macrophages/
140
If a certain protein's deficiency results in obestiy, what kind of BMI would we expect in patients with the highest levels of that protein?
Lower BMI, since they are less likely to be obese and they have the normal functioning protein
141
Sometimes the answer is not complicated and related to the passage. Look at the big picture and which one HAS to be true before changing the answer again
Sometimes the answer is not complicated and related to the passage. Look at the big picture and which one HAS to be true before changing the answer again
142
Cell proliferation does not mean weight gain
Cell proliferation does not mean weight gain
143
What is ampipathic vs. amphoteric?
Amphipathic means it has both hydrophilic and hydrophobic portionsm while an amphipathic compound is able to act as a base and acid.
144
Explain functions of Vitamins A, B, C, D, E, and K
A is involved in vision, B and C are coenzymes for reactions and the only water soluble vitamins, D helps in calcium and phosphate reabsorption from the GI tract, E is an antioxidant, and K promotes coagulation.
145
Make sure to translate graph results into words before choosing an answer, or even use multiple graphs for a conclusion
Make sure to translate graph results into words before choosing an answer, or even use multiple graphs for a conclusion
146
Do not choose answers that interpret a graph with conclusions that involve topics that are not directly discussed (better to choose the answer that says no change is present, no significant results, etc)
Do not choose answers that interpret a graph with conclusions that involve topics that are not directly discussed (better to choose the answer that says no change is present, no significant results, etc)
147
Where in a eukaryotic cell would you most likely find the highest concentration of lipid peroxides?
The mitochondria, since they are formed by free radical attack on a lipid.
148
Make sure to write out the genotypes of males and females for inheritance questions, to prevent confusion if they are similar
Make sure to write out the genotypes of males and females for inheritance questions, to prevent confusion if they are similar
149
For questions that ask what additional proof would prove the passage theory, make sure to fully understand the pathway
For questions that ask what additional proof would prove the passage theory, make sure to fully understand the pathway
150
Between trisomy 21 and trisomy 14, which is likely to be more detrimental?
Trisomy 14 because chromosome 14 has more genes. Trisomy 21 is harmful, but Down's Syndrome is survivable.
151
What is a nucleotide?
A 5 carbon sugar, nitrogenous base, and one to three phosphate groups (ATP is a nucleotide)
152
What are Ter and initiation proteins?
Proteins involved in termination and initiation of DNA replication, but they are not involved in elongation
153
What direction does DNA polymerase read?
It reads the parental DNA 3' -> 5' and creates new DNA that is 5' -> 3'
154
Why does DNA polymerase need a free 3' OH group provided by a short RNA strand?
This is the primer provided by primase enzymes. DNA polymerase and elongate but does not have an initial position to bind to. The free 3' OH group gives it the initial starting point. Since DNA is deoxygenated at the 3' position, this primer lets it bind
155
What direction is mRNA read in translation?
5' -> 3'. Make sure that you are looking at the DNA sense strand. If the DNA sense strand reads ATG, the mRNA codon will be AUG. The anti sense strand would be TAC, so the reverse compliment gives the mRNA codons. The tRNA anti codon is the complement to the mRNA codon, which would be UAC.
156
What do retroviruses do?
They can convert their RNA genomes into DNA through reverse transcriptase.
157
What specifically happens in a missense mutation?
An amino acid-coding codon is replaced by another amino acid-coding codon. If it was replaced with a stop codon, it would be a nonsense mutation. Start codons do not count
158
Where would the tRNA molecule be most likely to bind with the mRNA codon?
At the bottom of the t-shaped structure, or basically where the anti codon is found.
159
What is the function of the tRNA acceptor stem? What if it was shorter?
The acceptor stem plays a role in recognition of the tRNA by aminoacyl tRNA synthetase, which is responsible for attaching the correct amino acid to its tRNA. If it was shorter it would be harder for it to get recognized by this enzyme
160
What would happen if all rRNA was degraded suddenly?
Protein translation would be inhibited due to lack of ribosomes
161
Compare DNA and RNA
RNA has an extra OH group and is therefore more unstable and reactive. RNA in the form of ribozymes are able to catalyze biochemical reactions, but DNA cannot. Remember DNA is localized to the nucleus, but RNA (rRNA, tRNA, mRNA, etc) is found throughout the cell
162
Can RNA and DNA bond to each other?
Yes, they can hybridize. This must be true for transcription to occur.
163
What does the poly A tail do?
It prevents degradation of the transcript. Even though it is at the 3' end, it is not involved in termination. Also, the 5' cap is needed for nuclear export, not the tail
164
What is the induced fit model?
Says that an enzyme and substrate change their conformations slightly to accommodate each other's shape.
165
A mutation causes an enzyme to gain unusually high affinity for numerous substrates in addition to its intended one. If these new substrates bind to an allosteric site, how will it affect the intended reaction?
This is allosteric inhibition. There is a conformational change in the enzyme, causing it to be unable to bind to its original substrates. In this case the original reaction will not occur. This is non competitive inhibition
166
What are release factors?
These are factors involved in prokaryotic translation. Eukaryotic translation requires only one, which is eukaryotic translation termination factor (eRF1)
167
Protein release factors recognize stop codons and terminate translation. How many tRNA molecules bind similarly to stop codons?
None, tRNA does not bind to stop codons.
168
A human gene is placed into bacteria and it misfolds. Why would this happen?
Bacteria cannot take out introns, which causes misfolding
169
What type of DNA segments travel farther in electrophoresis?
Shorter bands travel farther
170
ssDNA can be made into dsDNA through treatment of DNA Polymerase I. How is this possible without a primer?
The 3' end can loop back on itself and act as a primer
171
etBR is a reagent that flouresces when it is allowed to intercalate between DNA base pairs. When using it in PCR, when would there be the must flourescence?
Flourescence would fluctuate because it is only active when DNA is positioned between stacked pairs, and intact helices are repeatedly formed and denatured during PCR.
172
What effect does Mg have on PCR?
Mg can occassionally coordinate strongly with the double helix and prevent denaturation. Mg is essential for PCR to proceed
173
What types of cells are pluripotent? What types are multipotent?
Embryonic cells are pluripotent because they can give rise to virtually any cell in the body. Adult cells are multipotent which can still differentiate into multiple types of cells, but embryonic are more widely useful
174
What is immunohistochemistry?
It uses antibodies that are specific to proteins in an attempt to determine which antigens are expressed in a certain region. In other words, it shows protein expression levels in a tissue (useful for cancer)
175
How do you restore transcription in a negative inducible operon?
In a negative inducible operon transcription is inhibited by a repressor in the basal state. Transcription can be activated by an inducer protein, which blocks the repressor from binding.
176
How do you increase the rate of transcription in a positive inducible gene?
In a positive inducible gene, the activator is incapable of binding the gene in the basal state. After adding an inducer, the activator can undergo a conformational change that allows it to bind DNA and initiate transcription.
177
A certain flower shows dominant characteristics for two alleles. What type of cross would allow them to determine genotype?
Crossing the unknown flower with a homozygous recessive. If any offspring demonstrate the recessive phenotype, the unknown individual must have been heterozygous.
178
How does mitotic prophase differ from meiosis prophase II?
In prophase II, there are half as many chromosomes present as in mitotic prophase. At the end of meiosis I, cells are already haploid and the number of chromosomes present in a typical somatic cell are already reduced to 23 when prophase II is reached
179
After a molecule has been engulfed by endocytosis, what other membrane-bound compartments does it go through before being degraded?
First the molecules are engulfed by an invagination of the cell membrane (vesicle) in endocytosis. They then deliver the contents to membrane-bound "early endosomes", which progress to "late endosomes". Then they fuse with lysosomes for degradation.
180
A student is studying the effects of removing ER from a cell. He is told it would cause near immediate cell death. Why?
Because the ER is connected to the outer leaflet of the nucleus. Removal of ER might disrupt the nuclear envelope, causing its contents to spill out and triggering apoptosis.
181
What type of filaments are involved in phagocytosis by macrophages?
Macrophages need to undergo rapid actin reorganization to engulf bacteria in phagocytosis.
182
If actin polymerization was inhibited, what cellular function is disrupted?
Cytokinesis. This uses a contracting ring of actin filaments to pinch daughter cells apart.
183
Eukaryotes perform respiration by pumping protons into the IM space. How do prokaryotes do this?
Since they lack membrane-bound organelles, they must use the plasma membrane.
184
What is the difference between autotrophs and heterotrophs?
Autotrophs fix carbon from the atmosphere and do not need to be given pre existing organic macromolecules.
185
What is true of viral capsids?
Most capsids are formed of repeated identical monomers, reducing the need for a large genome that contains multiple different genes for different capsid proteins
186
What type of enzyme is needed in a (-) RNA virus?
This is negative sense RNA, which is used as a template to produce (+) RNA by a viral polymerase that is carried within the capsid. An enzyme that makes RNA from an RNA template is called RNA-dependent RNA polymerase.
187
What type of event creates a genetic bottleneck?
Reduction in gene pool diversity because of a sharp reduction in population size, like from a catastrophic event
188
What is sympatric vs. allopatric speciation?
Sympatric speciation occurs when no physical barrier separates a population. Allopatric speciation occurs when there are physical barriers between the species (example-anatomical differences)
189
What is the number of autosomal chromatids in the G2 phase?
There are 26 chromosomes, and 52 chromatids when the cell is not undergoing division. But when it is in the S phase, each chromosome is duplicated resulting in 104 chromatids right before division.
190
Dont use the main idea too much for data based questions, sometimes the data disagrees with the hypothesis or some data may be irrelevant
Dont use the main idea too much for data based questions, sometimes the data disagrees with the hypothesis or some data may be irrelevant
191
What is the difference between germ line and somatic mutations?
If a mutation is somatic, it is found only in people that have the mutation and cannot be inherited. If the mutation transcripts are not found in the person's regular tissue, assume that it is somatic and cant be inherited
192
Dont change answers on the second look after finishing everything else, unless new information is found
Dont change answers on the second look after finishing everything else, unless new information is found
193
What are chaperone proteins?
Proteins that facilitate proper protein folding and inhibit the formation of non-functional protein aggregates. This includes heat shock proteins.
194
mRNA with a gene for a transmembrane protein will likely contain what type of genetic factor, a signal sequence or nuclear localization signal?
A signal sequence. Transmembrane proteins enter through the rough ER, which is facilitated by signal sequences. Nuclear localization signals are used to permit proteins to enter the nucleus
195
Nicotinamide nucleotides are neither oxidized or reduced during what step of cellular respiration?
Chemiosmosis, which is another term for the diffusion or protons for the proton pump and ATP synthase to make ATP
196
What is the number of fused rings in a steroid?
4
197
In what region of which structure does the glomerular filtrate reach its highest concentration?
The medullary portion of the collecting duct.
198
The Na+ K+ ATPase transport restores cell membrane potential after an action potential. Where do Na+ and K+ ions move?
This pump hydrolyzes ATP to pump these ions against their gradient. 3 Na+ ions are transported out and 2 K+ ions are transported in.
199
What do transcription factor proteins bind to?
Transcription factors bind to DNA and recruit RNA polymerase to bind to it and transcribe.
200
Will a big molecule with rings freely diffuse through the membrane?
A big and hydrophobic molecule with multiple rings can still diffuse through the cell membrane
201
What are lipid rafts?
Subdomains of the membrane that contain high concentrations of cholesterol.
202
What is the initial step in glomerular filtration?
Blood pressure forces the fluid in the glomerulus into the lumen of Bowman's capsule. The countercurrent exchange system only happens in the loop of Henle and collecting duct
203
To find the reason for an experiment, look for something about the basis or implications of the experiment being proved correct that is hinted in the passage
To find the reason for an experiment, look for something about the basis or implications of the experiment being proved correct that is hinted in the passage
204
Describe the bonds that covalently connect adjacent nucleotides.
Nucleotides are linked to one another by phosphodiester bonds between the sugar base of one nucleotide and the phosphate group of the other nucleotide, so that the 5' end bears a phosphate and the 3' end bears a hydroxyl group.
205
What are symptoms of diabetes?
Excess glucose in the blood, which leads to sweet tasting urine and catabolism of proteins and/or fatty acids. This can lead to unexplained weight loss and fatigue.
206
If DNA in a plate is all made of one isotope and then it replicates in the presence of another isotope, every single DNA double strand has one strand from each isotope. If replicated again, those "hybrid" DNA molecules remian, and the newly replicated ones are only the new isotope. So in the end, half of the DNA molecules have both the original and new isotope in the strands (hybrid) and the other half are exclusively the new isotope in each strand
If DNA in a plate is all made of one isotope and then it replicates in the presence of another isotope, every single DNA double strand has one strand from each isotope. If replicated again, those "hybrid" DNA molecules remian, and the newly replicated ones are only the new isotope. So in the end, half of the DNA molecules have both the original and new isotope in the strands (hybrid) and the other half are exclusively the new isotope in each strand
207
Be careful of Punnett square questions that have an answer that include two separate genotypes, which means include both in the fraction answer
Be careful of Punnett square questions that have an answer that include two separate genotypes, which means include both in the fraction answer
208
How do DNA acetylation and methylation affect transcription?
Acetylation promotes gene expression and methylation discourages it
209
What happens in the ascending and descending loop of henle?
In the descending portion, water is passively excreted as it descends lower towards the outer and inner medulla. In the ascending portion, Na and Cl are passively excreted at first, and then actively transported out as it ascends towards the cortex.
210
What are products of glycolysis?
1 glucose = 2 pyruvate + 2 NADH + 2 ATP + 2 water
211
What is nuclear localization sequence?
Its an amino acid sequence that tags a protein for import into the cell nucleus by nuclear transport.
212
What type of activity does reverse transcriptase have?
It creates double stranded DNA from a single stranded RNA molecule. First, it has RNA dependent DNA polymerase activity because it uses RNA as a template to create double stranded DNA-RNA hybrid. Then, it has DNA dependent DNA polymerase because it uses it to make double stranded DNA.
213
What is cell mediated immunity?
This involves T cells. Its an immune response that does not involve antibodies, but instead involves activation of phagocytes and cytotoxic T cells in response to an antigen. Humoral immunity is mediated by macromolecules in extracellular fluids like antibodies, complement, proteins, and certain antimicrobial peptides. Innate immunity is non specific defense like skin, chemicals in the blood, and immune cells that attack foreign bodies.
214
If an object is violet, what is the most likely maximum absorbance of it?
The wavelength reflected into our eyes is 400 nm (violet), but the wavelength of light absorbed is the wavelength of color that does not make it to our eyes, which is found at the opposite end of the spectrum (700nm red)
215
What is the order of small intestine parts?
Small intestine: duodenum, jejunem, ileum. Large intestine: cecum, colon, rectum.
216
What happens if a cell is arrested at a mitotic checkpoint?
Cells will constantly enter mitosis and become stuck in that phase. There will be a higher percentage of cells stuck in mitosis.
217
What happens to cells arrested in the G2/M checkpoint?
The cell cycle order is G1 S G2 M. This checkpoint is located after the S phase, so the cells will fail to pass the mitotic checkpoint that checks for possible damage incurred during the S phase.
218
What are the protein components of microtubules and microfilaments?
Tubulin mainly composes microtubules and actin primarily composes microfilaments
219
Before estimating the effect of new conditions, make sure the the changes proposed would actually make a difference: sometimes there is not enough supporting information in the passage to conclude that a new condition would change the outcomes
Before estimating the effect of new conditions, make sure the the changes proposed would actually make a difference: sometimes there is not enough supporting information in the passage to conclude that a new condition would change the outcomes
220
What are ACTH levels lowest? (at what level of cortisol)
ACTH levels are lowest when cortisol levels are high. Cortisol has negative feedback effects on ACTH, so when cortisol levels are high, ACTH is expected to be inhibited and be lower
221
For questions asking the cause of the disease choose answers that most directly relate to the symptoms. Be careful of answers that could be the result or cause of multiple things. Make sure the answer is narrow
For questions asking the cause of the disease choose answers that most directly relate to the symptoms. Be careful of answers that could be the result or cause of multiple things. Make sure the answer is narrow
222
You can connect graphs that are from the same experiment, just make sure that the measurements both apply to the same cellular process
You can connect graphs that are from the same experiment, just make sure that the measurements both apply to the same cellular process
223
What are the effects of the hormone Cholecystokinin?
It acts in the small intestine upon the entry of food. Its a peptide hormone that functions to aid digestion, including stimulating the pancreatic acinar cells to release digestive enzymes, stimulating feelings of fullness, inhibiting stomach emptying, and lowering gastric acid secretion. Somatostatin (growth hormone inhibiting hormone) inhibits the release of CCK.
224
Use POE to eliminate answers that are results of the disease, but that are not necessarily the cause they are looking for
Use POE to eliminate answers that are results of the disease, but that are not necessarily the cause they are looking for
225
Make sure to double check the nouns of the answer choices. The passage may say the protein is expressed by a specific protein, so the answer choice has to agree with this
Make sure to double check the nouns of the answer choices. The passage may say the protein is expressed by a specific protein, so the answer choice has to agree with this
226
What does parathyroid hormone stimulate, osteoblasts or osteoclasts?
PTH causes bone resorption through osteoclast activity, which break down bones and release the components back into the body.
227
What is a cDNA library vs. a genomic library?
cDNA library includes only the coding regions. It can easily be expressed through transcriptional processes. A genomic library is the entire genome which would be hard to express.
228
What is the PPP?
Takes G6P away from glycolysis and converts it into ribose 5 phosphate. 1 NADPH is produced in this step. Ribose 5 phosphate is used in nucleotide synthesis. This is the oxidative phase. In the non oxidative phase, the ribose 5 phosphate skeleton is rearranged, resulting in a net conversion to fructose 5 phosphate. F6P can be easily converted into G6P which can re enter glycolysis. This phase also produces glyceraldehyde 3-phosphate which can be used in glycolysis
229
How do ribosomes act as ribozymes?
They can play an assistive role in holding mRNA that allows amino acids to bond to the mRNA one at a time during the process of synthesizing them into a peptide chain.
230
Why does RNA not need SDS in electrophoresis?
RNA molecules already have a net negative charge proportional to the number of nucleotides (the phosphate backbone)
231
Make sure to compare the experimental conditions to the controls in the graphs. And make sure the answer choice references an exact category from the graph
Make sure to compare the experimental conditions to the controls in the graphs. And make sure the answer choice references an exact category from the graph
232
Where does the TCA cycle occur?
It occurs in the mitochondrial matrix in eukaryotes and the cytosol of prokaryotes.
233
Make sure the answer choice matches up with the graph results
Make sure the answer choice matches up with the graph results
234
Read longer discrete questions carefully and read it again after choosing an answer
Read longer discrete questions carefully and read it again after choosing an answer
235
Make sure the answer explains the question and its not just a true statement
Make sure the answer explains the question and its not just a true statement
236
How many molecules of cytochrome C are required to make 2 molecules of water in the cytochrome oxidase complex?
The cytochrome C oxidase complex (Complex IV) is the last enzyme of the ETC. It receives one electron from each of four soluble cytochrome C molecules, transferring them to a single oxygen molecule.
237
How does an isoelectric focusing apparatus work?
It separates by isoelectric points. The anode is positive and the cathode is negative.
238
What protein component forms the outer layer of skin?
The outer layer of skin is made up of keratin, which is an intermediate filament.
239
What would happen if male seminal vesicles were damaged?
Reduced fertility, because the seminal vesicles produce a basic solution to neutralize the acidic vaginal pH and help permit sperm survival. Remember, sperm production and maturation occur in the testes and epididymis.
240
What does the anterior pituitary secrete?
Secretes FSH and LH. The pituitary is stimulated by GnRH from the hypothalamus. Remember, testosterone is produced by Leydig cells in the testes, and is stimulated by LH. Spermatogenesis is promoted by FSH on Sertoli cells in the testes.
241
When is progesterone most active?
The luteal phase. Progesterone drops at the end of this phase, which triggers uterine contractions and causes menses (bleeding). It also drops right before birth and relieves the inhibition of contractions to promote birth. Remember, oxytocin stimulates contractions. Estrogen is high in the follicular phase, which occurs during the period (before the luteal phase). LH spikes right before the luteal phase.
242
What does estrogen do?
It is responsible for development and regulation of female reproductive system and secondary sex characteristics
243
Where does fertilization occur and what happens after?
Sperm and oocyte meet in the Fallopian tube. The zygote continues to travel down the tube until it reaches the uterus. Implantation occurs in the uterine endometrium
244
What is oxytocin and what secretes it?
It is secreted by the posterior pituitary. It increases the contractility and elasticity of the uterine wall. As a result, uterine contractions continue. Remember, this (parturition) is a rare positive feedback loop
245
What would happen in retrograde transport from the golgi apparatus?
Usually, proteins are packaged at the golgi and then sent out of the cell. In retrograde transport, the proteins go backwards and go back to the ER.
246
Why cant mouse antibodies created in an experiment be used in humans?
Using the same antibody in humans would elicit the response of the human immune system to make anti-mouse antibodies
247
What is the function of cytochrome c?
It cycles between a ferrous and ferric state during oxidative phosphorylation. It involves the transfer of a single electron
248
What is the quality of a good PCR primer?
High GC content at the 3' and 5' ends
249
If confused about the function/deficiency of an experimental variable, go back to the beginning of the passage to understand what it did in the first place. Be careful to gather results from a graph with different variables in it than the question is asking for
If confused about the function/deficiency of an experimental variable, go back to the beginning of the passage to understand what it did in the first place. Be careful to gather results from a graph with different variables in it than the question is asking for
250
What are protozoans?
They are eukaryotes
251
What is bacterial transformation?
When a bacterium acquires genetic material from the external environment
252
What is conjugation?
A bacterium directly transfers genetic material to another. This is what happens in the transfer of the F factor. Which codes for the sex pilus.
253
What is transduction?
It utilizes a bacteriophage as a vector for genetic exchange. A virus is a bacteriophage.
254
What are the starting materials that can be used in gluconeogenesis?
Lactate, glycerol, oxaloacetate, and alpha ketoglutarate can be used
255
What is involved in G protein signaling?
Activation of the coupled G protein involves an increase in the activities of adenylate cyclase, protein kinase, and the levels of cAMP are increased. It promotes dissociation of bound GDP in exchange for GTP on the alpha subunit
256
What enzyme is involved in the rate limiting step of glycogenolysis?
Glycogen phosphorylase
257
What types of linkages are present in glycogen?
Alpha 1-4 linear linkages with Alpha 1-6 branches
258
What is keto enol tautomerism?
Remember that enols, C=C-OH, can tautomerize into aldehydres, C-CH=O. If an aledhyde would test positive in a reducing test but the compound in question is an enol, then it would still test positive because it can tautomerize
259
What happens in a phase change?
Energy is either absorbed or released, but temperature will not change because all the energy lost or gained goes to achieving the phase change
260
What does thio mean?
It indicates the presence of a thio group
261
How does epinephrine affect glucose blood levels?
Epinephrine provides the body more access to glucose. It activates a G protein-coupled signal transduction pathway that activates glycogen phosphorylase to break glycogen down and inactivates glycogen synthase.
262
Control groups that receive placebos are usually a good modifier that can increase study reliability
Control groups that receive placebos are usually a good modifier that can increase study reliability
263
What is the R^2 value?
R^2 measures correlation. An R^2 value of 1 means the regression line is a perfect fit, while a value of zero means there is no correlation.
264
What is the brainstem?
It is comprised of the medulla oblangata, pons, and midbrain. The medulla is involved in regulating breathing, heart rate, and blood pressure.
265
What happens if vascular permeability is increased?
If vascular permeability is increased, the capillaries will leak fluid into extracellular compartments. This excess fluid shows up as edema and decreases blood pressure. As a result, renin production is increased to try and correct the hypotension
266
What are liver functions?
The liver regulates hepatic cholesterol, clotting factor synthesis, and bilirubin conjugation and excretion. Remember, digestive enzymes are not synthesized in the liver. Bile is synthesized in the liver, but it is an emulsifier not a digestive enzyme.
267
What factors affect ring stability?
Factors that cause ring strain: torsional strain caused caused by electron clouds of the molecule's substituents getting too close to each other, non-bonded strain caused by substituents on non-adjacent ring atoms being brought close together resulting in electronic repulsion, and angle strain caused by the bonding of electrons of ring atoms being brought closer (VSEPR and hybridization)
268
What are apoproteins?
A protein component that is unbound to its prosthetic group. Prosthetic groups are tightly bound organic molecules, like vitamins, that are required for enzymatic function. A cofactor is a non-protein component required for a molecule's biological activity.
269
What is PEPCK?
Phosphophenolpyruvate carboxykinase is an enzyme in gluconeogenesis that converts oxaloacetate to phosphophenolpyruvate and CO2.
270
An AB+ male has a child with an O+ female. What is the likelihood the child will be able to receive blood from a B- donor?
There is a 50% chance the child inherits his father's A allele and a 50% chance of inheriting the B allele.
271
How do you find number of stereoisomers present?
Stereogenic = stereoisomer. 2^(number of chiral/stereogenic centers), but stereoisomers also includes EZ configurations with double bonds that are not bonded to two identical substituents.
272
What is the difference between prokaryotic and eukaryotic DNA?
Both supercoil DNA, but eukaryotes have an additional level of supercoiling achieved with histones to squeeze more DNA into their nuclei. They differ in size, presence of introns, and number of origins of replication
273
What is quaternary structure?
Interactions between polypeptides due to hydrophobic interactions and bonds between side chains of amino acids
274
As molecule polarity decreases, hydrophobicity will increase. As electronegativity of the molecules decreases, polarity decreases as well.
As molecule polarity decreases, hydrophobicity will increase. As electronegativity of the molecules decreases, polarity decreases as well.
275
What happens to acidity upon addition of a flourine group to ethanol?
This increases polarity, which results in an inductive withdrawl of electron density of the proton creating a stronger acid. The electronegative F atoms pull electron density to themselves and stabilize the negative charge of the deprotonated form. Remember, resonance only has an effect with pi bond electrons
276
What does estrogen do?
Involved in the development of secondary sex characteristics during puberty. It is a steroid hormone.
277
What mechanism of gene transfer is involved in transferring genes from bacteria to eukaryotes?
Nuclear phage recombination is a virus acquiring bacterial genetic material and transferring to eukaryotes. Remember, conjugation and transformation is transfer between prokaryotes.
278
What does albumin do?
Serum albumin is the main carrier of free fatty acids in the blood
279
What is the cell membrane permeability to K and Na?
The membrane has high affinity for K+ and low affinity for Na+. So K+ moving inward will increase the interior positive charge.
280
What is hnRNA?
Heterogeneous RNA, which is a precursor for mRNA. mRNA is the only type of coding RNA
281
What is isoelectric focusing?
Separates by pI: a protein that is in the region of pH below its pI will be positively charged and migrate to the negative cathode. It stops migrating when it reaches the region of the gel where pH = pI because the net charge is zero and it does not experience an electric force. So use pKa's to decide which goes farthest, but basic residues travel farther than acidic residues.
282
What are the glia in the CNS?
Ependymal cells, astrocytes, and oligodendrocytes. Schwann cells are in the PNS.
283
What vitamin aids in collagen synthesis?
Vitamin C. Remember, vitamin A is used with retinol, B is a coenzyme for catabolism of sugars and AAs, and D enhances intestinal absorption of Ca and PO4.
284
What influences tertiary structure of a protein?
Covalent interactions between constituent amino acids (disulfide bridges), ionic bonding between side chains, and the hydrophobic effect
285
What germ layer includes the neural tube?
The ectoderm
286
What is a coenzyme vs. apoenzyme?
Coenzymes are small organic molecules that bind or donate functional groups to coenzyme-dependent enzymes. ATP is a coenzyme. Apoenzymes are inactive enzymes that lack a necessary cofactor.
287
Which terminus comes first in the polypeptide chain?
The N-terminus comes first and then the C-terminus comes last. So if you added an extra base in a chain, the amino terminus would be unaffected but the carboxy terminus is affected
288
Where do microtubules originate from?
The centrosomes, which is an organelle near the nucleus that contains centrioles and from which spindle fibers develop
289
What do cytotoxic T cells bind to?
They bind a viral antigen presented on a cell surface
290
What is convergent evolution?
Distantly related organisms independently evolve similar traits
291
What hormone axis does GnRH monitor?
Reproductive axis because it regulates pituitary gonadotropins-LH and FSH
292
What does histone acetylation do?
Promotes transcription by loosening chromatin structure
293
What complex of the ETC is succinate dehydrogenase?
Complex II
294
What is an imprinted gene?
A gene that is expressed in a parent specific manner. It is not X or Y linked because both sexes can carry the allele
295
What happens to osmotic pressure if malnutrition results in reduced amounts of protein in the blood?
Large plasma proteins increase osmotic pressure which causes water to move into blood vessels. With malnutrition, osmotic pressure decreases and water flows out towards body tissues causing edema. Remember the equation pi = iMRT. Osmotic pressure is directly proportional to molarity
