BP/Kaplan/AAMC B/B Flashcards
1
Q
michaelis menten
A
mm- vmax (s)/ km+(s)
2
Q
orthosteric
A
only at the active site
3
Q
how do phosphatases remove a phosphate
A
phosphatases do use water in their removal of a phosphate
4
Q
how does telomerase replicate dna? bc of this, what could u call telomerase?
A
Telomerase uses an RNA template to replicate DNA at chromosome ends (telomeres). As telomerase reads an RNA template, it is RNA-dependent DNA polymerase.
5
Q
non coding transposable elements- what can they do, and what is the effect of this?
A
Non-coding transposable elements can insert themselves into gene sequences, which is thought to thereby increase genetic diversity and able to accelerate evolution
6
Q
what is differential repro
A
Differential reproduction is the concept that some phenotypes are more fit than other phenotypes. Individuals with such phenotypes will survive and reproduce more frequently. This is the basis of natural selection, which drives evolution.
7
Q
species def
A
A species is normally defined as a genetically-similar group of organisms that can breed and produce fertile offspring. A species is reproductively isolated from other groups and cannot produce viable offspring with other species groups.
8
Q
what does HW apply to? what is it used for? is it real or hypothetical and why
A
Hardy-Weinberg equilibrium only applies to populations that are not evolving. It’s used to determine whether or not a population is evolving by comparing it to the predictions of Hardy-Weinberg equilibrium and to calculate genotype and allele frequencies within a population. Hardy-Weinburg is hypothetical, as all populations experience some form of evolution.
9
Q
whats inclusive fitness
A
Inclusive fitness expands the idea of genetic success beyond the individual to one’s relations. Since all of the wolves within a pack are closely related, they share many of the same genes. One wolf might help another wolf because their mutual survival promotes the survival of their shared alleles.
10
Q
explain p and q in HW eqn
A
p and q refer to ALLELE FREQUENCY. p^2 and q^2 refer to PHENOTYPE FREQUENCY
11
Q
gene flow
A
Gene flow is the movement of alleles between populations due to the migration of individuals between those populations.
12
Q
bottleneck effect
A
The bottleneck effect occurs when population allele frequencies change in response to a random decrease in population size due to external events, such as natural disasters. not related to adaptations that may already be preexisting.
13
Q
what can genetic drift cause and what can happena s a reult
A
Genetic drift can cause allele fixation, which occurs when one or more alleles of a gene are randomly eliminated from a population over time, resulting in only a single possible genotype at that locus.
14
Q
what is fitness
A
Fitness is a quantitative measure of natural selection, so it cannot be said to result in natural selection.
15
Q
when are viruses considered positive or negative sense
A
Positive-sense single-stranded RNA viruses contain RNA that can function as mRNA and be directly translated into protein. Viruses are considered negative-sense when their RNA is complementary to mRNA and must be copied into mRNA by the viral enzyme RNA replicase prior to translation.
16
Q
what is a retrovirus
A
Retroviruses are single strand RNA viruses. As such, their genetic material must first be reverse transcribed into DNA before it can integrate into the host genome.
17
Q
are retroviruses + or - sense? explain what happens to their genome and how they share their genetic info. can they survive on their own without other living things
A
Retroviruses are positive-sense ssRNA viruses. These pathogens have a single-stranded RNA genome that must be reverse transcribed to form DNA. The DNA is then transcribed into RNA and used to synthesize viral proteins. It should be noted that viruses are not living organisms, as they cannot survive on their own without other living organisms.
18
Q
what is the process for interpreting a figure. what is the order in which things should be read and looked at?
A
The process of interpreting a figure involves going from the general to the specific, and then back to the general. In other words, one should first read the figure legend to determine what the figure is about in general terms. Then, identifying the independent and dependent variables is a necessary prerequisite for understanding the relationships portrayed in the figure, which are further underscored by the units. Based on an analysis of the details of the figure, one can zoom out to make the figure tell a story.
19
Q
what is penetrance and expressivityt
A
Penetrance expresses a binary concept that a genotype’s corresponding phenotype will or will not be expressed. Expressivity expresses the degree to which a genotype’s phenotype s expressed, leading to a variable resultant phenotype.
20
Q
what are wild type traits
A
The term “wild type” refers to the traits an organism typically exhibits when found in nature. These may be dominant traits but not always.
21
Q
do linked genes assort independently and why or why not
A
Linked genes have a high likelihood of NOT assorting independently. If offspring phenotypes differ significantly from the expected Mendelian ratio of 9:3:3:1, the genes may well be linked.
22
Q
Concentration gradients established by primary active transport do what
A
This describes a concentration gradient. Concentration gradients established by primary active transport drive secondary active transport.
23
Q
what is primary active transport defined by? what does it not depend on? can both secondary and primary AT move molecules against conc gradient
A
Primary active transport is defined by energy consumption to move molecules against their concentration gradient. Primary active transport does not depend on whether or not those molecules can diffuse back across the membrane. Both secondary and primary active transport can move molecules against their concentration gradient.
24
Q
what do early endosomes do and not do
A
Early endosomes are responsible for sorting endocytosed vesicles and identifying what to do with the contents. They are not responsible for the actual degradation themselves.
25
does fac diff need energy and does passive dif? what do both rely on and what does this mean? explain how they are connected
Facilitated diffusion does not require any energy (either directly or indirectly) and nor does passive diffusion. Both rely on diffusion, which is the tendency of molecules to spread out and their concentrations throughout a solution to equilibrate. Facilitated diffusion is passive diffusion through a protein channel, and it helps very polar molecules cross the hydrophobic plasma membrane core.
26
what is a reporter gene
A reporter gene encodes a protein that creates visible phenotypic change. Whether the phenotypic change occurs allows the scientist to determine whether or not the recombination was successful, as successful recombination will include in the expression of the reporter gene.
27
conjugation
Conjugation refers to the transfer of genetic material directly between bacteria via a sex pilus (a bridge-like passage between two bacteria).
28
what doesEngineering plasmids with antibiotic resistance genes enable? When we treat a plate of bacteria with an antibiotic, what happens
Engineering plasmids with antibiotic resistance genes enable them to be separated on the basis of antibiotic resistance. When we treat a plate of bacteria with an antibiotic, only those containing the antibiotic resistance gene will survive. Those that contain this antibiotic resistance gene will also contain the gene of interest.
29
Glycoglycerolipids always have... and what about sphingolipids
Glycoglycerolipids always have a carbohydrate group attached, but only some sphingolipids have an attached carbohydrate group.
30
Sphingomyelin- what is it and what does it cluster with and why
Sphingomyelin is a glycolipid with a sphingosine backbone in place of the glycerol that is found in phospholipids and glycoglycerolipids. Sphingomyelin clusters with cholesterol to make lipid rafts, which modulate membrane fluidity and serve as organized clusters for various signaling processes.
31
what are glyceroglyoclipids and how are they similar to plipids and how are they diff
Glyceroglycolipids are a glycolipid type, which is a major class of membrane lipids. Glyceroglycolipids are similar to phospholipids in that they have a glycerol backbone and two fatty acid tails. However, glyceroglycolipids replace their phosphate group with a carbohydrate group.
32
esterification. also what occurs with esterification in plipids
Fatty acids can be attached to a glycerol molecule through a process known as esterification. In phospholipids, this happens to two out of the three hydroxyl groups. The remaining hydroxyl group is phosphorylated.
32
glycoglycerolipids v spingolipids- compare backbones, and head groups
Glycoglycerolipids and sphingolipids differ from each other in their backbone molecule: Glycoglycerolipids have a glycerol backbone and sphingolipids have a sphingosine backbone. Glycoglycerolipids and sphingolipids can contain the same hydrocarbon head group, but they still belong to their respective glycolipid subclasses because of their backbone.
33
hybridization
Hybridization is the process where single-stranded DNA or RNA form base pairs with its complementary strand. This is used in PCR to anneal DNA strands to each other.
34
what type of molecule moves further in gel ephoresis
Negatively charged molecules, not positively charged ones, tend to move further during gel electrophoresis.
35
PCR is used to
PCR is used to amplify genetic material prior to ligating genetic material into vectors. Thus, this is a potential application of PCR.
36
n Sanger sequencing...
In Sanger sequencing, all four ddNTPs are added to a single tube where DNA replication occurs.dNTPs elongate the DNA chain, while ddNTPs terminate replication.
37
what happens in primer extnesion
During primer extension, chains of various lengths are produced, all complementary to the template DNA. Since new strands are synthesized from 5' to 3', the 3' end of the complementary DNA chain will be nearest to the well, while the 5' end will be farthest. \
38
why is glucose not likely to cross the plasma membrane
Glucose’s polar groups make it less likely to be able to cross through the plasma membrane.
39
p53- activator or repressor
p53 is a transcription activator, not a repressor. It activates the transcription of genes that inhibit cell cycle progression.
40
defs of cytokines and microglia
Cytokines are protein-based signaling molecules secreted by cells of the immune system. Microglia are a macrophage derivative, a type of cell from the immune system, and as such will most likely secrete cytokines to modulate immune responses.
41
when can second msngers be made/ destroyed? can they be localized to other areas of the cell? give an example
Second messengers can be created or destroyed at times when the cell needs to turn the signal on or off, respectively. Second messengers can also be localized to specific areas of the cell in which they are needed, such as the cytoplasm or the endoplasmic reticulum.
42
Allergies occur when
Allergies occur when the immune system attacks a foreign molecule, such as pollen, that is actually harmless. In this example, the process begins when pollen in the air enters the lungs and the dendritic cell recognizes pollen as an antigen. The dendritic cell engulfs and presents pollen fragments on its MHC class II receptor to T cells. B cells differentiate into plasma cells which produce antibodies against the pollen.
43
do the intercostal muscles have an active role in inhalation? when may they contract? is exhalation passive or active
The intercostal muscles do not have an active role in inhalation. Intercostal muscles may contract during exhalation to more forcefully expel air but they are not necessary for exhalation either. Exhalation can be an active or passive process.
44
why is breathing active
Breathing is an active process because ATP is required for the diaphragm to contract and initiate inhalation
45
how does oxygen get to the bstream
Oxygen is transported out of the alveoli and into the bloodstream via passive diffusion down its concentration gradient. No energy is required for oxygen to diffuse out of the alveoli and into the bloodstream to be consumed by cells.
46
F-actin, which stands for “filamentous actin”, is a polymer composed of
This answer choice confuses the roles of G-actin and F-actin. F-actin, which stands for “filamentous actin”, is a polymer composed of G-actin monomers.
47
In the trp operon, tryptophan binds to the
repressor.
48
With transcription factors bound to the enhancer, DNA forms a
With transcription factors bound to the enhancer, DNA forms a 3-dimensional loop that brings the enhancer sequence within close proximity of a gene's promoter. The enhancer binds to the activator, which complexes with other transcription factors to bring RNA polymerase to the promoter.
49
what are enhancers and where are they found
Enhancers, DNA regions where transcription factors bind to upregulate gene expression, are found in both eukaryotic and prokaryotic DNA.
50
MicroRNA is responsible for and what does it do
MicroRNA is responsible for post-transcriptional silencing. These short, non-coding RNA molecules bind to mRNA, signaling its destruction or promoting degradation of its protective post-transcriptional modifications.
51
Silencers and enhancers are...
Silencers and enhancers are eukaryotic regulatory sequences that are bound by repressors and activators, respectively, to regulate the expression of target genes. RNA polymerase initially binds the promoter sequence before transcribing the target gene.
52
how does rna pol travel and synth
RNA polymerase travels in a 3’ to 5’ direction, synthesizing nucleotides in a 5’ to 3’ direction (due to the antiparallel orientation of the strands).
53
are only introns taken out
no, exons can b removed during alternative splicing too
54
which is the sense which is the antisense
RNA strands include the sense (coding) strand and the antisense (template) strand. mRNA is transcribed directly from the antisense strand, generating the same base sequence as the sense strand.
It makes SENSE to code
55
If a virus produces antisense RNA complementary to a gene’s promoter sequence,
the viral RNA will hybridize that sequence and prevent transcription from occurring.
56
Ribosome docking is fulfilled by
the 5' cap, not the poly(A) tail.
57
Prokaryotic mRNA is often polycistronic, meaning
which means that a single mRNA sequence may encode multiple proteins. Eukaryotic mRNA, on the other hand, is monocistronic.
58
describe rna in prokaryotes- is it ready to go? can transcription and translation happen at the same time on the same rna molecule?
In prokaryotes, newly synthesized RNA is ready to go and is immediately translated into protein. Since prokaryotes do not have nuclei to separate transcription and translation, the two processes may occur simultaneously on the same RNA molecule.
59
how do fatty acids enter enterocytes? does this process need energy
Because fatty acids are hydrophobic, they enter enterocytes by passively diffusing through the cell membrane. This transport process is much simpler than secondary active transport and does not require energy.
60
do absorbed and broken down mean the same thing
NO
61
rh factor
The Rh factor is a type of protein on the surface of red blood cells. + means u have it and - means u dont
62
type a=
type a antigens
63
in systole, is atria pressure higher than ventricles
During systole, the pressure in the atria is not higher than the ventricles.
64
where does gas nutrient and waste exchange occur? what does plasma do? how is interstitial fluid in the tissues returned to the circ system?
Gas, nutrient, and waste exchange occurs in capillary beds, and plasma from the circulatory system contributes to interstitial fluid in the tissues, which is returned to the circulatory system via lymphatic vessels.
65
When is glycolysis unregulated? What does a high atp to amp ratio mean
Glycolysis is upregulated when the cell needs more ATP. A high ATP to AMP ratio means that the cell has a lot of ATP compared to AMP, which is an energy-depleted form of ATP. In this situation, glycolysis would be downregulated.
66
which are the two reactions of glycolysis that require atp. are these reversibly and what do they require in gluconeogenesis in order to proceed
This statement is true. There are two reactions in glycolysis that require ATP: The conversion of glucose to glucose 6-phosphate and the conversion of fructose 6-phosphate to fructose 1,6-bisphosphate. Both of these steps are irreversible and require bypass reactions in gluconeogenesis.
67
does atp synthase pump protons
atp synthase doesnt pump protons
68
which are the highly regulated steps of the krebs cycle
acoa--> citrate, aketo--->succ coa, isocit---> aketo
69
A high ADP to ATP ratio means
A high ADP to ATP ratio means that the cell has more ADP than ATP, which suggests that the cell needs to make more energy.
70
This reaction is the third and final heavily regulated step of the citric acid cycle. It is inhibited by ...
This reaction is the third and final heavily regulated step of the citric acid cycle. It is inhibited by high levels of NADH and succinyl CoA.
71
Ubiquinone can accept two electrons from...
Ubiquinone can accept two electrons from either complex I or complex II, depending on whether they came from NADH or FADH2.
72
describe the lipid layers of mito.
This statement claims that mitochondria have four separate lipid bilayers, but in reality, each mitochondrion has only two: the inner and the outer membrane. These two bilayers are separated by the intermembrane space.
73
is complex 2 embedded in the membrane? can it pump protons from the matrix to the IMS why or why not
Although complexes I, III, and IV are embedded across the inner mitochondrial membrane, complex II is a peripheral membrane protein that does not span the inner membrane. As a result, it cannot pump protons from the matrix into the IMS like the other complexes do.
74
globular v fibrous proteins- are they hydrophilic/phobic, what do they tend to do?
Globular proteins tend to be hydrophilic, water-soluble, and often perform enzymatic functions. Fibrous proteins serve a structural role and are usually hydrophobic.
75
Aminopeptidases cleave amino acids from the ...
Aminopeptidases cleave amino acids from the N-terminus of a protein.
76
how does urea affect h bonding.
Proteins that are denatured in the presence of high urea concentrations are typically able to...
Urea disrupts hydrogen bonding, leaving the primary structure intact. Proteins that are denatured in the presence of high urea concentrations are typically able to re-fold once those concentrations are lowered.
77
what do reducing agents do to disulfied bridges
Reducing agents reduce disulfide bridges, breaking them back into separate cysteine residues.
78
what do detergents do
Detergents, which are amphipathic molecules, disrupt hydrophobic interactions in a protein.
79
why would gln be at the surface of a globular protein
Glutamine is a polar, uncharged amino acid, making it hydrophilic. Thus, it would be found at the surface of a properly folded, globular protein.
80
does an unfolded protein have more entropy than a folded protein? what about in the solvent?
An unfolded protein, which is flexible, disordered, and free to move, has greater entropy than a folded protein. In the solvent, though, an unfolded protein increases order because an organized solvation layer forms around nonpolar, hydrophobic groups in the protein that aren’t shielded in the inside of the protein when it is unfolded.
81
pH changes denature proteins by ...
pH changes denature proteins by altering the charges on specific groups within a protein. These changes disrupt ionic interactions between the side chains of charged amino acids.
82
When do solvation layers form
This statement is true. Solvation layers form around all solutes in solution.
83
how do proteins fold with hpobic and philic groups? how do solvent molecules interact with proteins?
A protein will fold so that hydrophobic residues are oriented inward and hydrophilic residues are oriented outward. This minimizes the solvation layer. Solvent molecules interact with the polar side chains of hydrophilic residues in a less ordered fashion, which is entropically favorable.
84
axial skeleton is what
axial skeleton houses cns. it also includes the ribcage, so it houses those organs as well
85
what are synovial joins? what do they have and what does this allow for
Synovial joints are freely movable joints. Synovial joints contain a synovial cavity, which is a fibrous, lubricated capsule that allows bones to enjoy significant freedom of movement without being directly joined together or bumping into each other.
86
what are osteons and what do they have in them
Osteons are cylindrical structures composed of concentric rings, or lamellae, of bone matrix. In the center of the osteon is a channel known as the haversian canal, through which the bone’s blood and nerve supply passes.
87
what hormone is raised when blood calc is low
When blood calcium is low, parathyroid hormone (PTH) becomes elevated to increase blood calcium levels via bone resorption, decrease urinary calcium excretion, and increase calcitriol synthesis. Thus, we would expect PTH levels to be elevated.
88
what is the bulk of a muscle made of
Although a muscle contains connective tissue which contains collagen, the bulk of a muscle is composed of muscle tissue.
89
is collagen found in skin
Collagen is found in the dermis of the skin.
90
sds- what does it do, what does it act like, which is the anode and which is the cathode
sds makes all proteins negatively charged. ephoresis needs an external power source, indicating it acts like an electrolytic cell. this means the anode is + with a higher pot and vv for cathode. thus the proteins will go to the + anode. RED CAT and AN OX
91
can dopamine cross the plasma membrane
dopamine relies on vesicular transport to cross the membrane. it isnt a nonpolar sterol or small gas molecule- these can cross unassisted
92
shadowing
a task in which a participant repeats aloud a message word for word at the same time that the message is being presented, often while other stimuli are presented in the background. It is mainly used in studies of attention
93
what do late endosomes do
Late endosomes are responsible for the identification and transport of substances that have been ingested via endocytosis and need to be degraded by lysosomes. However, late endosomes are not responsible for the actual degradation themselves.
94
True or false: The parasympathetic nervous system has a direct inhibitory effect on the nerves of the sympathetic system.
False. The two systems tend to have opposing effects on their target tissues. However, they do not function by exerting direct effects on each other. Rather, the two systems operate in parallel, and the dominant system is decided by external stimuli.
95
True or false: Sympathetic ganglia generally reside close to their effector tissues.
false. Sympathetic postganglionic neurons tend to be particularly long because the target tissue resides far from the ganglion. In contrast, parasympathetic ganglia tend to reside close to the target tissue; consequently, the parasympathetic system has longer preganglionic neurons.
96
Autonomic ganglia are
Autonomic ganglia are collections of cell bodies in the peripheral nervous system where preganglionic neurons synapse with postganglionic neurons.
97
which are longer, pre or post gang
Parasympathetic preganglionic axons tend to be relatively long, while postganglionic axons are relatively short.
98
medial geniculate
The medial geniculate body is involved in processing the auditory, not visual pathway.
99
lateral geniculate
The lateral geniculate body is a key relay point for the visual pathway that ultimately terminates in the primary visual cortex in the occipital lobe.
100
superior colliculus
The superior colliculus is a key relay point for the visual pathway that ultimately terminates in the primary visual cortex in the occipital lobe.
101
inferior colliculus
The inferior colliculus is involved in processing the auditory, not visual pathway.
102
Select all of the following that are directly involved in the propagation of voluntary motor control.
precentral gyrus, cerebellum, basal ganglia
103
which isnt in the cerebrum
thalamus is not in the cerebrum
104
where is the rhomboencephalon
hindbrain- think rhombo= rear
105
which senses go thru the thalamus
audiroty, visual, gustatory
106
what does myelin do to membrane resistance and membrane capacitance
increases resistance, decreases capacitance
107
what do excitatory postsyn potentials do to the cell memb also ipsp
they depolarize. ipsps hyperpolarize
108
events occurring in a typical action potential sequence
Sodium influx is responsible for the sharp upslope that marks the first phase of the action potential. At the peak of the action potential, potassium channels finish opening, and potassium efflux starts to drive the membrane potential back toward baseline. Inactivation of sodium channels shuts down sodium influx and is also responsible for the absolute refractory period. The characteristically slow potassium channels do not finish closing until the cell has already been hyperpolarized by the continued efflux of potassium.
109
why are larger neurons faster to conduct signals but harder to depolarize compared to smaller ones
Larger neurons have more area to store charge along their membranes and, therefore, they have a higher membrane capacitance, making them harder to depolarize. At the same time, larger neurons have lower cytoplasmic resistance than smaller ones, making them faster at conducting signals
110
what happens w na channels in the relative refractory pd? what abt the absolute refractory pd?
During the relative refractory period, sodium channels have closed, but can still potentially be opened again by a strong enough voltage, generating a second action potential. This contrasts with the absolute refractory period, during which the sodium channels cannot reopen
111
ligand gated are likely on which part of the neuron
dendrites
112
voltage gated are likely on the
nodes of ranvier
113
pka means what
the ph where the concentrations of conjugate acid and base are equal
114
if arg is at a ph of 11, what is that and what does it mean?
A pH of 11.0 corresponds to arginine’s isoelectric point (pI). Here, arginine’s carboxylic acid group and one of its two amine groups have been deprotonated, giving each molecule one -1 charge and one +1 charge. These charges cancel out and give the molecule a net charge of zero, making it a zwitterion.
115
Basic amino acids have how many pKa values?
Basic amino acids have three ionizable functional groups: a backbone carboxylic acid, a backbone amine, and a side-chain amine. Each of these groups has its own pKa value.
116
which amino acid would have an isoelectric point failry close to 6.1?
Valine, which has a nonpolar side chain, would have an isoelectric point fairly close to 6.1.
117
A characteristic of noncompetitive inhibitors is
A characteristic of noncompetitive inhibitors is that they bind the enzyme and the enzyme–substrate complex with the same affinity;
118
what is the genetic sequence of a retrovirus compared to the dna
Thus, the sequence of the nucleotide in the original viral genome will be the same as that of the transcribed mRNA. for a retrovirus
119
average weight of an amino acid
110 DA!!!!!!!!!
120
must memorize the structure of d glucose
look up a pic and then see if u can draw it from memory
121
l gluose v d glucose
that the bottommost free hydroxyl group, on C5, is pointing left in l glucose
122
The generalized empirical formula “Cm(H2O)n” holds true for what kinds of carbohydrates?
msach, disach, and psach. NOT dna sugars like ribose/deoxyribose
123
diff btwn glycogen and amylopectin
Glycogen contains many more alpha-1,6 bonds than amylopectin. This gives glycogen a greater degree of branching than amylopectin, allowing it to better serve its purpose as a storage molecule. Glucose chains in glycogen are more densely packed because of branching via alpha-1,6 bond. however, both of these do use aplha 1 6 and 14 bonds
124
deoxyribose v ribose
Deoxyribose differs from ribose in that it is missing a hydroxyl group at the carbon 2 position.
125
Lactase will breakdown what kind of glycosidic linkage?
Lactase breaks down molecules of lactose, specifically by hydrolyzing a beta-1,4 bond between a molecule of galactose and a molecule of glucose.
126
do epimers have equal but opposite optical activities
no, their optical activities are unrelated
127
why is the alpha anomer of d glucose less likely to form than the beta anomer
the beta anomer undergoes less electron repulsion
128
aldonic acids are compounds that
they form after the aldehyde group on a reducing sugar reduces another compound, becoming ox in the process. in other words, they have been ox and have acted as reducing agents
129
how many stereoisomers does glucose have
16. it has 8 d stereoisomers
130
mutarotation
spontanous change in config about c1
131
alpha v beta
orientation of the oh on the anomeric carbon
132
from a metabolic standpoint does it make sense for carbs to be ox or red
ox bc they are an energy source. they shld bcome ox while reducing other gorups bc aero metab needs reduced forms of e carriers
133
Tropic hormones directly induce physiological changes within non-endocrine tissues.
This statement is false. Tropic hormones act on endocrine cells and usually stimulate the release of other hormones. Only non-tropic hormones initiate changes within non-endocrine cells.
134
holocrine
Holocrine cells release molecules into the extracellular environment through membrane rupture. They do not secrete products into circulation.
135
merocrine
Merocrine cells are exocrine cells that secrete products locally through exocytosis. These secreted products do not travel throughout the body via the bloodstream.
136
endocrine
Endocrine glands like the thyroid release hormones into the bloodstream. Hormones act on target cells at a distance from the site of secretion.
137
apocrine
Apocrine cells are a subcategory of exocrine cells, which release molecules locally rather than into the bloodstream.
138
where are steroid hormones made? how do they enter the bloodstream
Steroid hormones are synthesized in the smooth ER. They diffuse directly through the ER membrane and the plasma membrane of the cell to enter the bloodstream.
139
Leptin is a hormone secreted by adipose tissue to inhibit hunger and reduce fat storage. The leptin gene is highly conserved in mammals. On a structural level, leptin contains several key secondary and tertiary features that promote the formation of disulfide bridges during folding. From this information, it can be inferred that leptin:
Because leptin contains secondary and tertiary structure and it forms disulfide bridges, we can infer that it is a peptide hormone. Peptide hormones bind to receptors on the extracellular surface of target cells, which initiates a signal cascade within the cell.
140
Which of the following treatments could help correct a chronic calcium deficiency?
Calcitriol is the hormonally active form of vitamin D. It helps regulate calcium homeostasis. Because calcitriol increases serum calcium levels, vitamin D supplementation could help correct a calcium deficiency.
141
The adrenal cortex secretes what type of hormones?
androgens.
142
which are the idiotic garbage tropic hormones
acth, crh, fsh, idk what else and i literally couldnt care less anymore im completely done trying
143
what does the garbage pth do???????wtf
prevents calc storage and stimulates osteoclast activity????? wtf?????
144
what do the alpha, delta and epislon cells produce
The alpha cells in the pancreas produce glucagon, delta cells produce somatostatin, and epsilon cells produce a hormone known as ghrelin.
144
In oogenesis, what is formed after the completion of meiosis II?
a primary oocyte
145
The primary oocyte spends most of its existence in which phase of meiotic division?
prophase 1
146
The secondaryy oocyte spends most of its existence in which phase of meiotic division?
metaphase 2
147
Put the following terms in the correct order to properly describe gas exchange between the mother and the fetus:
maternal O2, indirect exchange, umbilical vein, fetal CO2, and then umbilical artery.
148
Arrange the following stages of early embryonic development in the proper order from earliest to latest: morula, zygote, gastrula, and blastocyst.
zygote, morula, blastocyst and gastrula
149
Which of the following best describes the acrosome reaction?
once the sperm binds to glycoproteins in the zona pellucida, it releases digestive enzymes, which create a small tunnel through the zona pellucida and allows the sperm nucleus to enter the egg.
150
The liver houses the majority of the body’s glycogen supply. It helps maintain a healthy blood glucose level by taking up excess glucose after a meal and releasing glucose from storage when blood glucose levels get too lo
151
Each of the options below is a product of the pentose phosphate pathway. Which of the following are involved in the oxidative phase?
I. NADP+
II. Ribulose 5-phosphate
III. Fructose 6-phosphate
I and II only
152
True or False: Non-polar compounds will migrate further on a TLC plate than polar compounds.
true. TLC plates usually have a non-polar mobile phase and a polar stationary phase. Since “like dissolves like”, non-polar compounds will thus migrate further up the plate as the mobile phase - usually something like the solvent hexane - moves up the plate
153
True or False: A preparative purification tends to result in a larger amount of protein than an analytical purification.
true. A preparative purification is employed when a researcher wishes to have a large amount of the desired protein, while an analytical purification is used when a researcher desires a small, very pure protein extract for qualitative analysis.
154
MHC class I serves as an internal checkpoint. MHC class I receives protein fragments from inside the cell and presents the fragments on the outside of the cell to T cells. T cells play the role of quality control checkers.
155
Mhc class 2- what does it do
MHC class II serves to convey external information to the rest of the body. MHC class II is a way for the immune cells that destroy foreign objects to tell the rest of the body what they have found so that a coordinated response can be produced.
156
For the antibody titer, the synthetic varicella antigen is immobilized on a solid surface and the patient’s blood sample is added. If the patient has no previous exposure to varicella, the patient will have no antibodies specific to varicella in his blood. The test result will be negative, and the doctor would vaccinate the patient.
157
A pathogen must first be phagocytosed by an antigen-presenting cell, then broken down into peptide fragments inside a lysosome. Next, these peptide fragments must be packaged and sent to the cell surface attached to an MHC II complex. Lastly, this MHC II must be recognized by a T cell with the appropriate CD4+ co-receptor and a T-cell receptor that is specific for that pathogen.
158
True or false: The cell-mediated immune response targets host tissue, not foreign pathogens.
This statement is true. The cell-mediated immune response, or the T cell branch, does not directly target pathogens in the way that the humoral response or various components of the innate response do. Instead, cytotoxic T cells target host cells that have been infected by the pathogen in question, destroying them to prevent the cell’s internal machinery from being used to further spread the infection.
159
Plasma cells are immune cells specialized to produce immunoglobulins, also known as antibodies. B cells differentiate into plasma cells, which then produce immunoglobulins.
160
T lymphocytes are involved with cell mediated immunity, not humoral immunity.
161
Each kidney is protected by a tough, fibrous external layer called the renal capsule. The renal cortex, which constitutes the outer layer of the kidney, lies directly within the renal capsule. The innermost region of the kidney is called the renal medulla.
162
. The renal medulla is more hypertonic than the renal cortex because the concentration of solutes increases dramatically as you move from the outermost region of the cortex into the deepest part of the medulla. This osmotic gradient is established by the loop of Henle.
163
Water is reabsorbed into the vasa recta in the descending limb of the loop of Henle and ions are reabsorbed in the ascending limb. These actions depend on concentration gradients between the loop of Henle and the vasa recta, which is maintained by the countercurrent multiplier system. If blood in the vasa recta were to flow in the same direction as the filtrate in the loop of Henle, their solute concentrations would quickly equalize and the flow of water and solutes between them would stop.
164
The ascending limb of the loop of Henle facilitates the reabsorption of ions into the renal medulla. This creates an osmotic gradient within the medulla that allows water to flow passively out of the descending limb.
165
The renal corpuscle is connected to the renal tubule. Filtrate generated in the corpuscle feeds directly into the renal tubule for additional processing before it becomes urine.
166
What do insulin-responsive cells do in the presence of insulin?
Secretory vesicles containing GLUT4 transporters in their membranes fuse with the cell plasma membrane.
Correct Answer
GLUT4 transporters are stationed in the membrane of secretory vesicles waiting for their signal, and in response to insulin, these vesicles fuse with the plasma membrane, allowing glucose to move into the cell from the bloodstream.
167
what is the idiotic garbage transporter involved with glucose
GLUT2 NOT GLUT 4@!!!!!!
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For pancreatic beta cells, glucose enters through the GLUT2 transporter, not the GLUT4 transporter. GLUT4 transporter expression is insulin dependent so it makes sense that to initiate insulin release, we would need to use a different transporter whose expression is not dependent on the presence of insulin.
169
GLUT4 transporters move glucose into the cell via:
FAC DIFF
170
wtf is glut 4????????????
171
what does insulin inhibit and why
Insulin inhibits glycogen breakdown, or glycogenolysis, because insulin is released when blood glucose levels are high (i.e., when the body does not need more glucose).
172
what does glucagon do post secretion?
After glucagon is secreted, it binds to G-protein coupled receptors in the plasma membrane, which initiates an intracellular signaling cascade to inhibit anabolic processes and promote catabolic processes. These catabolic processes include the breakdown of glycogen and the synthesis of glucose from other sources in a process known as gluconeogenesis.
173
what do fatty acids contain? waht does this mean for trans and sat fatty acids
Fatty acids that contain a trans double bond are incredibly stackable, much like saturated fatty acids. Due to this structural feature, both trans and saturated fatty acids tend to be solid at room temperature. Since cis double bonds introduce a kink in the fatty acid chain that disrupts intermolecular forces, cis fatty acids tend to have much lower melting points and are typically liquids at room temperature.
174
why are trans fats more stackable and what is another characteristic in regards to their state of sl or g
Because trans fats do not bend like cis-unsaturated fatty acids, they are more stackable and pack tightly together, which allows them to resist heat. They tend to be solid at room temperature.
175
what determines melting and bp? what do fatty acids w trans db compared to cis db have and what does this mean for them
. Melting and boiling point are determined by intermolecular forces. Fatty acids that contain trans-double bonds are more stackable than fatty acids that contain cis double bonds, which introduce a kink into the chain. Therefore, trans fats are likely to be solid at room temperature.
176
if a figure has non overlapping error bars what does this mean for significance
If a figure doesn't contain an indicator of statistical significance, but error bars between two groups of data are non-overlapping, then for the purposes of the MCAT the difference between the two groups is significant.
177
Values either are significant or are not significant, based on whether or not they are below an arbitrary cutoff. It would be meaningless to compare the extent to which two experimental results are significant – they either are or are not.
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western blotting
used to detect proteins
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Northern blotting
Northern blotting is used to detect RNA sequences,
180
southern blotting
Southern blotting is used to identify specific DNA sequences
181
adenoviruses are
dna viruses
182
When performing experiments to measure the kcat of an enzyme, the substrate concentration should be:
saturating. the kcat is used to describe the rate-limiting step of catalysis under saturating conditions of substrate
183
when should you use a log-log operation to linearalize a graph?
Log-log operations should be carried out on data that needs to be linearized. For example, a dataset that can be described with the equation y = m*xb would produce a parabolic curve, which could be linearized by log-logging it
184
what are non categorical variables
Variables that exist on a numerical spectrum are non-categorical. Continuous variables, and another kind called discrete variables, describe any variable that is non-categorical
185
is hair color and sex categorical vbles
ya they are. sex is biological. gender is a different thing
186
how does co2 travel in the blood
binds hemoglobin, dissolves in plasma
187
positive hydropathy index means the
positive hydropathy index means the amino acids are hydrophobic, and therefore more likely to reside within a plasma membrane
188
what accompanies G protein-coupled receptor activation
the exchange of GDP for GTP in the α subunit is what accompanies G protein-coupled receptor activation.
189
Specific activity is a measure of:
the enzyme units per milligram of total protein in a soln
190
how does uracil come from cytosine
in the deamination of cytosine, the amine group of cytosine is replaced with a carbonyl group, resulting in the structure of uracil
191
what happens in an addition reaction
In an addition reaction, the number of pi bonds declines, while the number of sigma bonds increases
192
in cation exchange, the stationary surface attracts
cations
193
relationship between reactivity and ability of the lg
the more reactive smth is, the better lg it makes
194
what is the reaction with oxygen at the end of etc
o2+4h+4e--->2H2O
195
Which enzyme plays the most direct role in breaking branched linkages during glycogenolysis?
Branch points in glycogen consist of α (1→6) linkages. These linkages are broken by an enzyme aptly termed glycogen debranching enzyme.
196
Which of the following describes how hexokinase and glucokinase are regulated to prevent excess glycolysis
Hexokinase is inhibited by high levels of G6P, while glucokinase is inhibited by low blood sugar.
197
how do you find the mass of a homotetramer given no other information on earth except its weight in sds page, the most useless thing on the planet
the enzyme is active as a homotetramer, which means that the molecular weight given by SDS-PAGE is four times less than the active molecular weight.
198
how do u number cytosine
start from the N- thats 1
199
what charge would a protein with a low pi have at ph 7
protein with a low pI would be negatively charged at pH 7
200
what type of exchange column do ANIONS bind to
anion exchange!!!!!!
201
why would you need a high amt of nacl to elute some idiotic substance from a column
if its tightly bound
202
describe fermentation
The process of fermentation results in the reduction of pyruvate to form lactic acid and the oxidation of NADH to form NAD+. Electrons from NADH and a proton are used to reduce pyruvate into lactate.
203
retrograde transport
retrograde means backwards. so normally stuff goes from the ER to the golgi. so retrograde means it would have been sent bacvk to the ER
204
do bacteria have a mechanism to splic out introns? is their size relevant to expression prevention?
bacteria dont have a mechanism to splice out introns, size of the bac doesnt prevent expression since only the coding region is transferred.
205
how many electrons does cytochrome c transfer and why
cyto c cycles btwn fe2+ and fe3+ states, therefore only 1 e is transferred in the proces
206
best thing for a pcr
its with a lot of GC and CG bases.
207
what is the head of a fatty acid
the head of a fatty acid is a co2,a carboxyl group
208
give exampls of stuff that comes from the ecto, endo and mesoderm
most of the lining of the mouth is from ectoderm. the bronchi r from endo, bladder is from mesoderm and endoderm and stomach linig from endo
209
order of filtrate passing thru the nephron
glom- proximal- loop of henle- distal- collecting duct
210
proximal tubule
filtrate first enters here. 70 of sodium filtered will be reabsorbed here.
211
loop of henle
ascending- only na reabsorp and descending- only water reabsorpb
212
distal tubule
responds to aldosterone and na reabsorption
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collecting duct
collects filtrate. last stop for reabsorption. since its going down it reminds me of the bus to rock bottom from spongebob- last stop
214
3.order of events after blood pressure drops
BP drops--> renin cleaves angiotensinogen ---> angiotensin 1----> ace enzyme makes atensin 2---> aldosterone is releasted from the adrenal cortex
215
what does each part of the neprhon do when it comes to active transport (excretory system EOC, #3)
The proximal tubule accounts for the majority of transport along the nephron. The descending loop of Henle only allows for passive reabsorption of water, so we can eliminate choices A and B. The ascending loop of Henle is impermeable to water, and has to actively pump ions out of the nephron. As a result, it has thick walls filled with mitochondria to help satisfy the energy needs of active transport.
216
Which of the following pairings of a part of the nephron with its function is NOT correct?
A.
Proximal convoluted tubule—hormone-controlled reabsorption and secretion
B.
Loop of Henle—creation of osmotic gradient
C.
Ascending limb of the loop of Henle—NaCl reabsorption
D.
Collecting duct—concentration of urine
The proximal convoluted tubule is the site of major reabsorption and secretion, but this is largely driven by sodium transport, not hormone activity. It is the distal convoluted tubule that is involved with hormone-controlled reabsorption and secretion.
answer is A
217
what do u need to have a net filtration pressure?
To have a net filtration pressure, the net pressure must favor movement of fluid from the capillary into the Bowman’s space. If we define fluid movement into the Bowman’s space (i.e. filtration) as positive, and fluid movement into the glomerular capillary as negative, we want the net sum of all the pressures to be positive.
218
sanger sequencing explanation
In Sanger sequencing, the target DNA is copied many times, making fragments of different lengths. Fluorescent “chain terminator” nucleotides mark the ends of the fragments and allow the sequence to be determined.
219
sds page- is a type of and which size protiens move faster
small pass easily and its a type of gel ephoresis i think. SDS PAGE is a type of gel electrophoresis used for separating macromolecular proteins of size between 5 kDa and 250 kDa. Proteins, unlike RNA and DNA, are not charged negatively and do not move toward the positive or negative end.
220
All nucleic acids are a
All nucleic acids are a linear arrangement of the component nucleotides,
221
a Southern blot uses a
restriction digest to differentiate between mutant and wild-type alleles.
222
in order for a Southern blot to be useful,
the mutation should either create or eliminate a restriction site, most of which are palindromes and 4 to 6 base pairs long. The mutation shown in this option is the only one that disrupts a palindromic sequence, AAGCTT. This sequence is the recognition sequence for HindIII.
223
Where do post-transcriptional modifications of RNA take place in human cells?
nucleus. examples include capping, splicing, and polyadenylation
224
can ecoli go btwn the appendix and colon? where shouldnt it go
The appendix is continuous with the colon so that bacteria can move between these two structures; a ruptured appendix would allow E. coli into the abdominal cavity, which is not normal.
225
The limit of resolution of a light microscope is about
200 nm.
226
Bacteria and eukaryotic cells such as the human red blood cell are well above that size (200 nm) so they can be seen with a
light microscope
227
Non-cellular media such as____ _______ and _________ will not support culture of viruses.
nutrient broths and suspensions
228
translation refers to
taking the RNA, a series of nucleotides, and putting it into protein language, a series of amino acids.
229
what does increased glucagon caused
inc gluconeo and inc keptones
230
HDL= ?
LDL=?
hdl= good, ldl= bad
231
vitamin a- what does it do
plays a role in tissue growth
232
vitamin b
fxn in the prod of multiple cofactors. largest group of vitamins
233
vitamin d
inf on bone growth and calc resorption
234
vitamin e
most well known for its antiox capabilities
235
hypothalamic–pituitary–adrenal axis (HPAA)
hypothalamus, pit gland and adrenal gland and their fxns are included
236
"more blasting gas im nervous"
morula to blastula to gastrula to neurulation
237
utr=
untranslated region
238
ss and ds
double stranded and single stranded
239
lytic cycle
a virus causes the cell to lyse in the process of using the cells machinery w little regard for the survivial of the host cell. once in the lytic cycle, viruses are termed virulent. seems to use the cell to make copies of itself and then lyses.
240
lysogenic cycle
doesnt cause lysis. just integrates into host genome and doesn cause lysis. the bacteria may become less susceptible to superinfection with other phages. seems to integrate dna and then multiply thru cell replication.
241
Positive-sense single-stranded RNA viruses contain RNA that
can function as mRNA and be directly translated into protein.
242
Viruses are considered negative-sense when
their RNA is complementary to mRNA and must be copied into mRNA by the viral enzyme RNA replicase prior to translation.
243
what type of amplification is pcr
linear
244
heterochromatin v euc
hetero- dense
eu- light
245
does insulin act directly on glucose in the blood
no
246
sds page
SMALLER moves FARTHER
247
endoderm
epithelium that lines the primitive gut. From this epithelial lining of the primitive gut, organs like the digestive tract, liver, pancreas, and lungs develop.
248
mesoderm
musculoskeletal system (bone, cartilage and muscle), cardiovascular system (heart, blood and blood vessels), as well as the connective tissues found throughout our bodies.
249
ectoderm
some epithelial tissue (epidermis or outer layer of the skin, the lining for all hollow organs which have cavities open to a surface covered by epidermis), modified epidermal tissue (fingernails and toenails, hair, glands of the skin), all nerve tissue, salivary glands, and mucous glands of the nose and mouth.
250
defunct dna replication
this in the bacteria would prevent cells from even replicating to begin with
251
which way does a protein go post release of ribosome
when translated by er bound ribosome., it goes rer- golgi-plasma membrane-extracell space
252
order of devp
zygote, mor, blas, gast, 3 germ, endodermal layer, lining of archenteron(hollow gut cavity) and gi system
253
opsonization
is how antibodies bind to and recognize antigens on pathogen surface
254
what is the f factor w bacteria
f factor= fertility factor
255
transformation and transduction
In transformation bacteria take up DNA from their surroundings, the media in which they are immersed. Transduction is the process whereby genes are transferred by a virus.
256
is bone connective tissue
YES
257
Translation of antibody proteins in eukaryotic cells is associated with what organelle?
. Synthesis is accomplished by the ribosomes, which are associated with the endoplasmic reticulum
258
thyroxin is regulated by
thyroid stimulating hormone (TSH).
259
glycogen) is formed by glycosidic bonds between
glucose molecules through α(1→4) linkage linearly and α(1→6) linkage at branch point.
260
Therefore any event that causes the dissipation of the electrochemical gradient across the inner mitochondrial membrane will result in
decreased level of protons in mitochondrial intermembrane space.
261
Adaptive radiation involves
the divergence of one species into multiple species over time, which can occur when subgroups of the original species are separated or isolated in different environments so that these subgroups evolve independently of one another.
262
Polarity in neutral molecules results from
an uneven distribution of electron density, which can arise from separation of unlike charges. This occurs in zwitterions and in ylides.
263
A fatty acid would have the general formula Rn—CO2H. The corresponding fatty acid salt would have the general formula
Rn—CO2– Na+.
