Premed95 All Decks - Copy2 Flashcards
1
Q
all amino acids exist as ___
A
zwitterions
2
Q
what is cortisol?
A
stress hormone
3
Q
as acidity increases, HgB’s affinity for O2 ___
A
decreases
4
Q
centrosomes CONTAIN
A
centrioles, composed of microtubules
5
Q
the citric acid cycle produces GTP, T/F
A
T
6
Q
Calcium released from the sarcoplasmic reticulum binds to
A
troponin
7
Q
what is the function of the loop of henle?
A
water reabsorption
8
Q
how does competitive inhibition work?
A
binding reversibly to the active site
9
Q
what happens to the Km and Vmax in competitive inhibition?
A
Vmax unchanged, Km increases
10
Q
what does an uncompetitive inhibitor bind?
A
the E-S complex
11
Q
what happens to the Vmax and Km of uncompetitive inhibition?
A
Lowers Vmax and Lowers Km
12
Q
where do noncompetitive inhibitors bind?
A
at a location other than the active site
13
Q
what happens to the Km and Vmax during noncompetitive inhibition?
A
Km remains the same, decreases Vmax
14
Q
gut flora are found mostly in the __
A
cecum
15
Q
what is the function of DNA ligase?
A
joining strands of DNA together
16
Q
what is the equation for osmotic pressure?
A
PI=iMRTwhere i= # of solute particles and R is ideal gas constat
17
Q
what is beta oxidation?
A
cleaving the beta carbon next to the COOH group
18
Q
what does chymotrypsin do?
A
cleaves peptide bonds preferentially near hydroPHOBIC amino acids
19
Q
pyruvate is converted to acetyl CoA in the
A
mitochondrial matrix
20
Q
pyruvate is converted to acetyl CoA by
A
pyrvuate dehydrogenase
21
Q
what are prosthetic groups?
A
nonprotein components of enzymes required for enzymatic activity. NOT part of original AA sequence of protein
22
Q
what is an enoyl?
A
carbonyl with a double bond between alpha and beta carbons
23
Q
each FADH2 produces __ ATP
A
1.5
24
Q
each NADH produces __ ATP
A
2.5
25
can viral budding occur in bacteria?
no, because prokaryotes have a cell wall
26
would a pyrimidine-->pyrimidine mutation affect structure?
no
27
what is thyroxine?
associated with thyroid, responsible for regulating metabolism
28
what is the founder effect?
phenomenon where certain areas of world show higher allele frequency than others
29
does salinity affect enzyme rate?
yes
30
where is oxytocin made?
hypothalamus
31
what are pseudopodia made of?
microfilaments
32
what are actin and myosin made of?
microfilaments
33
where is the mitral valve located?
between the left atrium and left ventricle
34
what is an apoenzyme?
enzyme lacking its cofactor
35
what is a holoenzyme?
enzyme+coenzyme
36
what lipid is the component of myelin?
sphingomyelin
37
which channel repolarizes the membrane to its resting potential?
K+ (potassium)
38
a cell that isn't dividing but metabolically "active" is in what stage of the cell cycle?
G0 or G1.
39
what does the diaphragm do during inspiration
contracts
40
what do the intercostal (rib) muscles do during inspiration?
contract
41
what happens to the pupil during the sympathetic response
DILATES
42
when are primary oocytes made?
between fertilization and birth
43
glomerular filtration rate is dependent on
blood pressure
44
what do the kidneys do in response to decreased blood pressure?
activate renin-angiotensin system to increase sodium and water reabsorption, increasing blood volume and pressure
45
what is adaptive radiation?
divergence of one species into multiple different species which can occur when the original species is geographically isolated
46
what causes a neuronal depolarization?
sodium ions moving IN
47
what does calcitonin do?
DECREASE blood calcium(think: it "tones down" blood Ca)
48
what does parathyroid hormone do?
INCREASE blood calcium
49
what are sertoli cells?
provide nourishment for developing sperm cells
50
what are the steps in spermatogenesis?
spermatogonium-->primary spermatocyte-->secondary spermatocyte--> spermatid-->spermatozoan
51
what is unique about exocrine glands?
secrete through ducts
52
what does the pancreas produce?
proteolytic enzymes (chemotrypsin)
53
what is the function of ADH?
anti-diuretic hormone, fxns to increase water reabsorption and urine concentration
54
what is the function of the descending loop of henle?
water reabsorption
55
what is the function of myoglobin?
STORAGE of O2, no transport
56
what direction does RNA polymerase travel in? what direction does it synthesize in?
travels: 3-->5synthesized: 5-->3
57
what kind of polymerase is found in a retrovirus?
RNA dependent DNA polymerase
58
what is the function of the leaky potassium channels?
maintainence of resting membrane potential
59
what is a zymogen?
inactive form of protein
60
are shorter wavelengths(higher freq) more likely or less likely to be absorbed by body tissue?
more likely
61
how many phosphates are attached to each nucleotide in DNA?
2
62
where does the H-bonding occur between nucleotides?
between the PYRIMIDINE rings (benzene looking things)
63
what property of the lipid sphingomyelin makes it important for action potentials?
its conductivity(or lack thereof), as conductivity and insulation are related
64
error bars are a measure of___
PRECISION
65
what is an ideal control group?
has all the factors of the test group except the thing being tested
66
what are T cells activated by?
antigen presenting cells
67
what are antigen presenting cells?
B cells, macrophages, dendritic cells
68
what to antigen presenting cells do?
display a MHC
69
neutrophils and macrophages are part of the
innate immune system
70
what is a spliceosome?
splices from RNA not DNA
71
what does DNA methylation do?
suppress transcription by condensing chromatin
72
how many ATP are produced in glycolysis?
2 total. 4 in, 2 out.
73
what are the 3 stop codons on DNA?
TGA, TAA, TAG
74
what does a kinase do?
transfer phosphate from high energy molecule (GTP or ATP), to substrate
75
what does a phosphatase do?
removes phosphate group from substrates
76
what is the function of a fibroblast?
produce ECM
77
what does prolactin do?
stimulate breast milk PRODUCTION
78
what does oxytocin do?
stimulate breast milk RELEASE (as well as uterine contractions, etc)
79
what is the function of VLDL? (very low density lipoprotein)
carry fatty acids AWAY FROM liver
80
what does HDL do?
carries stray fatty acids and triglycerides TO liver
81
what is the ploidy of a secondary spermatocyte? and of a primary spermatocyte?
n, 23/ 2n, 46
82
what direction does DNA polymerase READ in?
3-->5
83
what direction does DNA polymerase SYNTHESIZE in?
5-->3
84
what is the function of lutenizing hormone?
stimulate leydig cells to promote testosterone-->make sperm
85
what is the function of CD8 cells?
detect and kill INTRACELLULAR pathogens
86
what is the function of CD4 T cells?
helper cells, release cytokines and help suppress or regulate immune response
87
what is the function of B cells?
releasing antibodies
88
maltose is the product of?
amylose breaking down starch
89
what connects the cells in cardiac muscle?
GAP JUNCTIONS (aka electrical synapses)
90
what do tight junctions do?
TIGHT joining of cells, prevent movement of shit
91
what does the sodium potassium pump do?
pumps 3 Na+ out and 2 K+ in. Net output of 1+ out of cell, maintains negative potential INSIDE CELL
92
what do cytotoxic T cells do?
kill cancer cells or infected/damaged cells
93
what is the function of a dendritic cell?
process antigen material, and present it to T cells. act as messengers between adaptive and innate immune system
94
what is the difference between a coenzyme and a cofactor?
a coenzyme is ORGANIC, while a cofactor is not (usually a metal ion or something)
95
what event precedes the release of opening of Na+ channels on the motor end plate, resulting in depolarization of muscle fibers?
binding of acetylcholine
96
what do reducing conditions do in gel electrophoresis?
disrupt disulfide bonds
97
what do denaturing conditions do during gel electrophoresis
disrupt interactions between monomers allowing primary structure to be analyzed
98
what is the significance of the hill coefficient?
higher than 1 meants enzyme exhibits cooperativity
99
what is the G1/S checkpoint?
checkpoint before transcription takes place
100
what is kD?
binding affinity constant
101
what does CO2 and H2O create?
carbonic acid (H2CO3)
102
is pressure lower or higher in the lower extremities?
HIGHER
103
the GLUT4 is only found in
adipose tissue and muscle
104
what is a chaotropic agent?
disrupts H bonding networks (fucks up enzymes)
105
at a pH below the isoelectric point, a protein will have a net
POSITIVE charge
106
how do you find the pI of an amino acid without any acidic/basic side chains?
take the averages of the amino and carboxy pKas. w
107
what is the pKa of the carboxy terminus?
2
108
what is the pka of the n-terminus?
~10
109
what ribsomal subunit type is associated with eukaryotes?
80s
110
what ribosomal subtype is associated with prokaryotes?
70s
111
how many reading frames does prokaryotic mRNA have?
multiple
112
how is the lagging strand synthesized?
short RNA primers
113
a large kD means
unfavorable interaction, low binding affinity
114
the GI tract is derived from
endoderm
115
what is opsonization?
when antibodies bind to antigens on a pathogen
116
what happens to insulin levels after a meal?
increase
117
what are the fat soluble vitamins?
ADEK
118
where can lipid peroxides be found in the cell, and why?
mitochondrial membrane because that is where the ETC is and Oxygen is taking place in redox reaction
119
what is trisomy 21?
downs syndrome
120
what is trisomy 14?
DEATH! why? because it has more genes
121
do polar or charged amino acids play a part in dimerization of proteins?
no because they interact with the cytosol preferentially.
122
how does SDS page separate proteins?
based on mass
123
glucose 6-phosphatase plays a role in
gluconeogenesis and glycogenolysis
124
how do you calculate kcat?
Vmax/Km(or[E])
125
what are some starting materials for gluconeogenesis?
lactate, oxaloacetate, alpha-ketoglutarate
126
what happens to the Galpha subunit of a GPCR when a ligand is bound?
exchanges bound GDP for a GTP
127
what enzyme catalyzes the rate limiting step in glycogenolysis?
glycogen phosphorylase
128
phosphogluconate is involved in
the pentose phosphate pathway
129
succinyl CoA synthetase produces
succinate and GTP
130
what is the product of the pentose phosphate pathway?
NADPH
131
what does glucose 6 phosphate dehydrogenase do in the pentose phosphate pathway?
catalyze conversion of glucose 6 phosphate into 6-phosphogluconolactone
132
what primarily composes the secondary structure of proteins?
H bonding between backbones
133
alpha helix and beta sheets are an example of
secondary structure
134
disulfide bridges are what level of protein structure?
tertiary
135
trypsin and lipase function in what part of the body?
small intestine
136
cytokinesis is possible because of what protein structure?
microFILAMENTS
137
prokaryotic flagella are made from ___
flagellin, different from eukaryotes
138
what are the stages of interphase?
G1-->S-->G2
139
the y intercept in a linweaver-burke plot represents
1/vmax
140
how many electrons does cytochrome c carry?
ONE
141
ideal PCR primers have
a high G-C content
142
when does nondisjunction occur?
anaphase 1 or 2
143
which amino acids are used to make proteins?
only L
144
what is euchromatin?
loose, easily accesible to transcription machinery
145
what is the vasculature schema?
Arteries-->arterioles-->capillary bed-->venules-->veins
146
the lower the Kd, the higher the
binding affinity
147
what does a protease do?
hydrolytic cleavage of proteins
148
what embyronic germ layer is the mouth derived from?
ectoderm
149
what does lipase do?
hydrolyze fatty acids/fats
150
proteins destined for the cell membrane have a
signal sequence to bind to rough ER
151
what does calcium do in the context of muscle movement?
binds troponin-->pulls tropomyosin away from actin-myosin binding site which allows myosin to bind actin
152
where is glomerular filtrate the most concentrated?
medullary collecting duct
153
what do ABC transport proteins do?
transport shit OUT of cell
154
what is a lipid raft?
cholesterol rich domain in plasma membrane
155
the initial filtration step in the kidney occurs due to
pressure difference in bowman's capsule
156
nucleotides are bonded to eachother by
5-->3 phosphodiester bond
157
is loss of appetite a Sx of DM?
NO
158
is glycolysis exergonic or endergonic?
exergonic
159
what is the fate of pyruvate in gluconeogenesis?
reduced to glucose and NADH oxidized to NAD+
160
what is the function of NADPH produced by the pentose phosphate pathway?
assists antioxidants
161
vesicle exocytosis does what to membrane surface area?
INCREASES it
162
what does aldosterone do?
increases sodium reabsorption, which increases blood osmolarity, which increases ADH production-->more water reabsorpton-->increae in blood volume and pressure
163
what does the krebs cycle produce for each acetyl CoA?
1 FADH2, 4 NADH, 1 GTP
164
what does the movement of Cl- ions into an neuron do?
hyperpolarizes it and prevents it from firing an action potential
165
hyperpolarization of a neuron prevents its ability to
release neurotransmitters
166
a frameshift mutation only affects
translation
167
what are the assumptions for hardy-weinberg?
infinte population, random mating, no movement in or out
168
a low Km indicates
higher binding affinity between enzyme and substrate
169
what controls the anterior pituitary?
factors released by the hypothalamus
170
what controls the posterior pituitary?
neuronal stimulus from the hypothalamus
171
what is a proto-oncogene?
a gene that, when mutated, becomes an oncogene
172
what is endothelium?
simple squamous cells that line blood and lymphatic vessels
173
epi and nor-epi are produced by
the adrenal medulla
174
where do epi and nor-epi bind?
the cell surface because they are derived from amino acids and are polar
175
what happens during prophase?
spindle apparatus forms, centrioles move to poles, nuclear membrane disintegrates, chromatin condenses
176
what is produced in oogenesis?
1 ovum after 2 divisions
177
what is the 32 cell stage called?
blastula
178
what is the 16 cell stage called?
morula
179
what is the 1 cell stage called?
zygote
180
what does the parasympathetic nervous system do to blood vessels?
contracts them
181
what is IgA?
immunoglobulin that protects against toxins, bacteria, and free floating viral cells
182
what does ACTH do?
stimulate adrenal cortex to produce cortisol and aldosterone
183
how many carbons are in pyruvate?
3
184
how many carbons in oxaloacetate?
4
185
what is the sign for enthalpy(H) for an endothermic reaction?
positive(requires heat)
186
what does a positive deltaH mean
rxn requires input of heat
187
a positive deltaH and positive delta S means the reaction
is spontaneous at high temperatures
188
ketogenesis uses ___ as substrates
fatty acids
189
a decreased Km indicates
increased substrate affinity/increased velocity
190
can noncompetitive inhibition be overcome with increased substrate concentration?
NO
191
competitive inhibition can be overcome with
greater [S]
192
what kind of sugar does NADPH contain?
ribose(pentose) because it is a nucleotide derivative
193
fatty acid oxidation occurs in the
mitochondrial matrix
194
pyrvuate is converted to acetyl coA in the
mitochondrial matrix
195
increasing pKa of side chains means the isoelectric point
also increases
196
when pH is less than pKa
protonated
197
gastrin is produced by
G cells in the antrum of the stomach
198
do peptides contain ester bonds?
NO
199
how do you calculate recombination frequency?
of recombinants/total # of offspring
200
to find overall frequency if the genes are unlinked
multiple each probability together
201
what happens to the allele frequency in hardy weinberg?
remains the same
202
how to draw glucose easily?
D glucose is right left right right, L glucose is left right left left
203
are actin filaments polymerized in muscle contraction?
NO
204
what happens to FSH levels after menstruation?
The are high
205
what hormone increases to instigate ovulation?
LH
206
what does aldosterone do to blood K levels?
decreases them because of increased K secretion
207
what do exonucleases do?
repair base pair mismatches
208
the conversion of pyruvate to oxaloacetate requires
CO2
209
what is a missense mutation?
one AA substituted for another
210
what is a nonsense mutation?
leads to a premature termination
211
how do you measure catalytic efficiency?
kcat/Km
212
anion exchange columns bind:
negatively charged anions
213
how do you calculate Vmax given [E] and kcat?
Vmax=kcat[E]
214
when both substrates occupy an active site, what kind of complex is formed?
ternary complex
215
a sigmoidal shape indicates
cooperative binding
216
how does a blood pressure reading occur?
constrict until no flow is heard. the first point at which it is heard is systolic, the point at which it is no longer heard again is diastolic
217
where are the bonds occuring in the secondary structure of a protein?
between backbone amide protons and carbonyl oxygens
218
pyrimidines are
CUT6 member rings
219
phosphofructokinase-1 is inhibited by
ATP allosterically
220
secretory proteins are synthesized and folded in the
rough ER
221
what is ubiqutination?
targeting a protein for degradation by proteasomes
222
what does glyceraldehyde-3phosphate-dehydrogenase do?
catalyze conversion of G3P to 1,3-biphosphoglycerate
223
what does vasopressin do?
regulates insertion of aquaporins into collecting duct
224
what are schwann cells?
myelin producing cells of PNS
225
what are oligodendrocytes?
myelin producing cells of central nervous system
226
blood from the small intestine flows to the
liver
227
internalization of viruses by endocytosis would be mediated by
endosomes
228
what do proteases do?
digest proteins into smaller fragments
229
phosphoenolpyruvate is a product of
glycolysis
230
how many ATP are produced per glucose in anaerobic conditions?
2 per glucose
231
which part of the antibody recognizes foreign pathogens?
the tip of each light/heavy chain
232
in muscle contraction the ___head binds to the ___ filament
myosin head, actin filament
233
why is ATP required for muscle contraction?
required to break myosin-actin bond
234
what does a reducing agent do in electrophoresis?
breaks disulfide bonds
235
the conformational changes that allow actin/myosin to move relative to one another requires
ATP hydrolysis
236
reuptake of calcium into the sarcoplasmic reticulum requires
ATP
237
the terminal electron acceptor in fermentation is
pyruvate
238
what are platelets formed from?
megakaryocytes
239
do platelets have ribosomes?
yes
240
increased blood O2 and decreased blood CO2 does what to pH?
increases it (respiratory alkalosis)
241
is actin thick or thin?
THIN(acthin)
242
is myosin thick or thin?
THICK
243
what is the difference betwen nucleoside and nucleotide?
nucleotide has PHOSPHATE, whereas nucleoside just has the sugar and base
244
what is the rate limiting enzyme for glycolysis?
PFK-1
245
what is the rate limiting enzyme for gluconeogenesis?
fructose-1,6-biphosphatase
246
whats the rate limiting enzyme for the TCA cycle?
isocitrate dehydrogenase
247
whats the rate limiting enzyme for glycogenesis?
glycogen synthase
248
what is the rate limiting enzyme for glycogenolysis?
glycogen phosphorylase
249
what enzyme converts pyruvate to oxaloacetate in gluconeogenesis?
pyruvate carboxylase
250
what converts oxaloacetate to phosphoenolpyruvate?
PEP carboxylase
251
what enzyme catalyzes the conversion of fructose1,6biphosphate to fructose 6 phosphate?
fructose16biphosphatase
252
what enzyme produces glucose from glucose-6-phosphate in gluconeogensis?
glucose-6-phosphatase
253
is arginine or lysine more basic?
arginine
254
what is unchanged in uncompetitive inhibition?
Km/Vmax
255
what is the slope of a lineweaver burk plot
Km/Vmax
256
what is specific activity?
enzyme units per milligram of total protein
257
what elutes first in size exclusion chromatography?
allows smallest to elute first
