Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

USMLE Buzzwords > 1201-1400 > Flashcards

1201-1400 Flashcards

1
Q

What G protein is stimulated by activated rhodopsin?

A

Gt (transducin), which decreases cyclic guanosine monophosphate (cGMP) and closes the Na+ channels, causing nerve transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the vitamin K-dependent clotting factors?

A

2, 7, 9, and 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What vitamin is connected to selenium (Se) metabolism?

A

Vitamin E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the activated form of vitamin E?

A

Alpha-tocopherol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What elements make up a nucleoside?

A

A base and a sugar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the most common methylated base?

A

Cytosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

DNA is replicated at what phase of the cell cycle?

A

S phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

At which end of DNA are new bases added?

A

3’ end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What keeps single-strand DNA (ssDNA) from re-annealing during DNA replication?

A

Single-strand (ss) binding protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What enzyme is responsible for producing a single-strand (ss) cut in the DNA to relieve the coil tension?

A

Topoisomerase I (relaxase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What two amino acids are found in high concentrations in the nucleosome?

A
  1. Arginine 2. Lysine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What three bases are pyrimidines?

A
  1. Cytosine 2. Uracil (only in RNA) 3. Thymidine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What enzyme creates a short sequence of RNA to start DNA replication?

A

Primase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of enzyme is reverse transcriptase?

A

RNA-dependent DNA polymerise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the direction of transcription?

A

5’ to 3’ direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where is the TATA box in located eukaryotes?

A

25 bases downstream (-25)(promoter)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What causes transcription to stop in eukaryotes?

A

The poly(A) site on the DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What protein binds to the promoter region in eukaryotes to initiate transcription?

A

TF II D (transcription factor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What part of the 30S ribosome binds to the Shine-Dalgarno sequence?

A

16S subunit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the start codon for translation?

A

AUG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the enzyme that activates the amino acids for the tRNA?

A

Aminoacyl-tRNA synthetase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is needed to direct enzymes to a lysosome?

A

Phosphorylation of mannose residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What cofactor is needed for lysyl oxidase?

A

Cu2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What part of the 50S and 60S ribosomal subunit is needed for elongation?

A

Peptidyl transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In the lac operon: At which site is the repressor gene encoded?

A

I gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

To which site does the repressor protein bind in order to inhibit transcription?

A

Operator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What amplification technique is used to generate a larger amount of DNA?

A

Polymerase chain reaction (PCR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What test is used to determine whether a gene is expressed?

A

Northern blotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

At what organ in the body is urea produced?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What regulatory proteins work during fetal development to ensure that cells become a specific cell type (If there is a defect here, there can be profound structural mutations.)?

A

Homeobox genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the mode of inheritance in which a trait is seen in every generation and is passed on only by females?

A

Mitochondrial inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the name for the process of going from mRNA to proteins?

A

Translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the components of a nucleotide?

A

A base, a sugar, and a phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What enzymes hydrolyze 3’-5’ phosphodiesterase bonds from the outside of the strand in?

A

Exonucleases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What type of organisms have monocistronic mRNA?

A

Eukaryotes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

In collagen, every third amino acid is this amino acid.

A

Glycine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What form of continuous DNA, used in cloning, has no introns or regulatory elements?

A

c-DNA, when it is made from mRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What proteins stimulate a cell to enter the S phase?

A

Growth factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

At what pH is there no net charge on the structure?

A

pI (isoelectric point)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What complex of the ETC contains Cue+?

A

Complex 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What two shuttles are needed to keep NAD+ in the reduced state?

A

Malate/aspartate and glycerol-3-phosphate shuttles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What vitamin is required for y-carboxylation of many Cat+-binding proteins?

A

Vitamin K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

From where is the energy for gluconeogenesis derived?

A

ß-Oxidation of fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What amino acid is broken down into N20, causing an increase in eGMP of smooth muscle resulting in vasodilatation?

A

Arginine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What hormone phosphorylates enzymes to decrease their activity?

A

Glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Lack of what enzyme can lead to Wernicke-Korsakoff syndrome through lack of activity in the HMP shunt?

A

Thiamine pyrophospate (TPP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What enzyme found in the liver catalyzes glycerol to glycerol-3-phosphate?

A

Glycerol kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Which shuttle is used to bring fatty acyl CoA from the cytoplasm for ketogenesis?

A

Carnitine acyl CoA transferase II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Which enzyme is deficient in phenylketonuria (PKU)?

A

Phenylalanine hydroxylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

After approximately how many days of a prolonged fast does death occur in humans?

A

60 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the cause of death?

A

The breakdown of the essential proteins of the heart and brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

All the carbons in a fatty acid are derived from what source?

A

Cytoplasmic acetyl CoA that left the mitochondria as citrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What enzyme is deficient in alcaptonuria?

A

Homogentisic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

In a diabetic patient, glucose is converted by aldose reductase to what?

A

Sorbitol (resulting in cataracts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What glycolytic intermediate can be used to synthesize triglycerides and phospholipids?

A

DHAP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What glycolytic enzyme has a high Vmax high Km and low affinity for glucose?

A

Glucokinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is the main inhibitor of pyrnvate dehydrogenase?

A

Acetyl CoA (pyruvate to acetyl CoA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What are the two substrate-level phosphorylations in glycolysis?

A
  1. Pyruvate kinase 2. Phosphoglycerate kinase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What are the eight liver-specific enzymes?

A
  1. Fructokinase 2. Glucokinase 3. Glycerol kinase 4. PEPCK 5. Pyruvate carboxylase 6. Galactokinase 7. Fructose-1,6-biphosphate 8. Glucose-6-phosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

In what cycle does glucose go to the muscle, where it is converted to pyruvate and then into alanine before being taken back to the liver?

A

Alanine cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

In what cycle does glucose go to the muscle, where it is converted to lactate, and then returned to the liver?

A

Cori cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What four substances increase the rate of gluconeogenesis?

A
  1. Glucagon 2. NADH 3. Acetyl CoA 4. ATP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What enzyme is deficient in a patient who presents with: Liver damage and severe hypoglycemia?

A

Aldolase B (hereditary fructose intolerance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Jaundice, vomiting, lethargy, cat, galactosemia, and galactosuria?

A

Galactose 1-phosphate uridyltransferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What three substances stimulate glycogenolysis?

A
  1. Cat+:calmodulin ratio 2. Epinephrine 3. Glucagon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the two inhibitors of complex I of the ETC?

A
  1. Rotenone 2. Amytai (barbiturates)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the five factors that constitute the pyruvate dehydrogenase complex?

A
  1. TPP 2. Lipoic acid 3. CoASH 4. FAD 5. NAD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What attaches to protons and allows them to enter into the mitochondria without going through the ATP-generating system?

A

24-Dinitrophenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are the two decarboxylation steps of the TCA cycle?

A
  1. Isocitrate dehydrogenase 2. a-Ketoglutarate dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What are the three inhibitors of complex IV of the ETC?

A
  1. Cyanide 2. CO 3. Azide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What three steps of the TCA cycle generate NADH?

A
  1. Malate dehydrogenase 2. Isocitrate dehydrogenase 3. a-Ketoglutarate dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What disease presents with weakness and cramps on exercise without an increase in blood lactate levels?

A

McArdle’s disease (muscle glycogen phosphorylase deficiency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

NADPH generated from the HMP shunt is used for what?

A

Fatty acid synthesis, nucleotide synthesis, and glutathione reductase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Is linolenic acid an omega-3 or -6 fatty acid?

A

Omega-3; linoleic is omega-6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Is the oxidative reaction of the HMP shunt reversible or irreversible?

A

Irreversible (G-6-PD and 6-phosphogluconate dehydrogenase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What disease presents with an enlarged liver and kidneys, dwarfism, hypoglycemia, acidosis, and hyperlipidemia?

A

Von Gierke’s disease (glucose 6-phosphatase deficiency)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

At what three sites can the HMP shunt enter into glycolysis?

A
  1. Fructose-6-phosphate 2. Glucose-6-phosphate 3. Glyceraldehyde-3-phosphate 1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Deficiency in the liver glycogen phosphorylase enzyme is known as what?

A

Hers disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What causes the lysis of red blood cells by oxidizing agents in a glucose-6- phosphate dehydrogenase deficiency?

A

The lack of glutathione peroxidase activity results in a decrease in NADPH production, leaving glutathione in the reduced state.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What disease presents with hepatomegaly and a normal EKG?

A

Glycogen storage disease, type III (Forbes disease, Cori disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What apoprotein is on the surface of LDL?

A

Apoprotein B-100

82
Q

What carries cholesterol from the tissues back to the liver?

83
Q

What apoprotein mediates the uptake of remnants by the liver?

A

Apoprotein E

84
Q

What is the complex needed for acetyl CoA carboxylase?

A

Biotin, ATP, and G02 (acetyl CoA to malonyl CoA)

85
Q

What are the three tissues where TAGS are produced?

A
  1. Liver 2. Muscle 3. Adipose tissue
86
Q

What delivers cholesterol to the tissues?

87
Q

What apoprotein is produced by the intestinal epithelium?

A

Apoprotein B-48

88
Q

What carries TAGS to the peripheral tissues?

89
Q

How many NADPHs are used per addition of each of acetyl CoA into a fatty acid chain?

A

2 NADPHs/acetyl CoA

90
Q

What apoprotein activates lipoprotein lipase in the capillary epithelium to hydrolyze TAGS?

A

Apoprotein C-II

91
Q

What apoproteins are on the surface of IDL?

A

Apoproteins B-100 and E

92
Q

From which two substances are phospholipids made?

A
  1. DAGs 2. Phosphatidic acid
93
Q

What apoproteins are on the surface of HDL?

A

Apoprotein A-I, C-II, and E

94
Q

What is needed to produce a double bond in a fatty acid chain in the endoplasmic reticulum?

A

NADPH, O2, and cytochrome b5

95
Q

What apoprotein activates lecithin cholesterol acyl transferase to esterify cholesterol from tissue?

A

Apoprotein A-I

96
Q

What apoproteins are on the surface of VLDL?

A

Apoproteins B-100, C-II, and E

97
Q

At the end of each round of ß-oxidation, what is released?

A

Acetyl CoA, FADH, and NADH

98
Q

What two enzymes are vitamin B12 dependent?

A
  1. Homocysteine methyl transferase 2. Methylmalonyl CoA transferase
99
Q

What enzyme is blocked by disulfiram?

A

Aldehyde dehydrogenase

100
Q

What hormone hydrolyzes TAGS to free fatty acids and glycerol?

A

Hormone-sensitive lipase

101
Q

What enzyme is deficient in a patient 2 years of age or younger who presents with vomiting, lethargy, coma, hypoketosis, and hypoglycemia following a fast of more than 12 hours?

A

Medium-chain acyl dehydrogenase

102
Q

What form of alcohol did the patient drink if he became blind as a result?

A

Methanol (wood alcohol)

103
Q

What regulates the rate of ketone body formation?

A

The rate of ß-oxidation

104
Q

What intermediate enables propionyl CoA to enter into the TCA cycle?

A

Succinyl CoA

105
Q

What sphingolipid is formed by the union of serine and palmitoyl CoA?

A

Sphingosine

106
Q

What intermediate of cholesterol synthesis anchors proteins in the membranes and forms CoQ?

A

Farnesyl pyrophosphate (FPP)

107
Q

What is the complex needed for propionyl CoA carboxylase?

A

Biotin, ATP, and C02

108
Q

What are the three ketone bodies?

A
  1. Acetoacetate 2. Acetone 3. ß-hydroxybutyrate
109
Q

What type of damage to the kidneys is caused by drinking ethylene glycol (antifreeze)?

A

Nephrotoxic oxylate stones

110
Q

What is the only sphingolipid that contains choline and p04?

A

Sphingomyelin (lecithin also, but it is not a sphingolipid)

111
Q

What is the order of fuel utilization in a prolonged fast?

A
  1. Glucose from liver glycogen 2. Glucose from gluconeogenesis 3. Body protein 4. Body fat
112
Q

Sialic acid and amino sugars are needed to produce what sphingolipid?

A

Ganglioside

113
Q

What vitamin is needed as a cofactor for decarboxylation and transaminase reactions?

A

Vitamin B6

114
Q

What are the two ways that nitrogen can enter into the urea cycle?

A
  1. Aspartate 2. Carbomoyl PO4
115
Q

What is the only enzyme in the body that uses N5 methyl folate?

A

Homocysteine methyl transferase

116
Q

What enzyme deficiency will result in an increase in blood ammonia and an increase in uracil and orotate concentrations in both the blood and urine?

A

Ornithine transcarbamoylase (OTC) deficiency-also called ornithine carbamoyltransverase (OCT) deficiency

117
Q

What amino acid is a precursor of the following substances: Serotonin?

A

Tryptophan

118
Q

What amino acid is a precursor of the following substances: GABA?

119
Q

What amino acid is a precursor of the following substances: Histamine?

120
Q

What amino acid is a precursor of the following substances: Creatine?

A

Glycine/arginine

121
Q

What amino acid is a precursor of the following substances: NAD?

A

Tryptophan

122
Q

What amino acid is a precursor of the following substances: N20?

123
Q

What enzyme deficiency will result in an increase in blood ammonia, but no increase in uracil concentrations?

A

Carbamoyl-phosphate synthetase

124
Q

What are the glucogenic and ketogenic amino acids?

A

Phenylalanine, Tyrosine, Tryptophan, Isoleucine, Threonine

125
Q

What are the three diseases of sphingolipids?

A
  1. Niemann-Pick disease 2. Gaucher’s disease 3. Tay-Sachs disease
126
Q

What type of jaundice is seen in Rotor’s syndrome?

A

Conjugated (direct) hyperbilirubinemia

127
Q

What is the pyrimidine intermediate that joins PRPP?

A

Orotic acid

128
Q

What three amino acids are used to synthesize the purine ring?

A
  1. Glycine 2. Aspartate 3. Glutamine
129
Q

What enzyme is blocked by hydroxyurea?

A

Ribonucleotide reductase

130
Q

What is the primary end product of purine synthesis?

131
Q

What enzyme is deficient in hereditary protoporphyria?

A

Ferrochelatase

132
Q

What are the two precursors of heme?

A
  1. Glycine 2. Succinyl-CoA
133
Q

What enzyme is blocked by 5-FU?

A

Thymidylate synthetase

134
Q

What disease has a genetically low level of UDPglucuronate transferase, resulting in elevated free unconjugated bilirubin?

A

Gilbert’s syndrome

135
Q

What form of bilirubin can cross the blood-brain barrier?

A

Unconjugated free bilirubin

136
Q

What substrates are needed to produce carbamoyl P04 (de novo pyrimidine synthesis)?

A

Glutamine, CO2, and ATP via carbamoyl PO4 synthetase II

137
Q

What enzyme is blocked by methotrexate/trimethoprim?

A

Dihydrofolate reductase

138
Q

What type of jaundice is seen in Dubin-Johnson syndrome?

A

Conjugated (direct) hyperbilirubinemia (It is a transport defect.)

139
Q

What form of bilirubin is carried on albumin?

A

Unconjugated (indirect)

140
Q

In what disease is there a genetic absence of UDPglucuronate transferase, resulting in an increase in free unconjugated bilirubin?

A

Crigler-Najjar syndrome

141
Q

What enzyme is deficient in acute intermittent porphyria?

A

Uroporphyrinogen I synthetase

142
Q

What enzyme is deficient in congenital erythropoietic porphyria?

A

Uroporphyrinogen III cosynthase

143
Q

What amino acid has a pKa of 13?

144
Q

What two amino acids have a pKa of 10?

A
  1. Lysine 2. Tyrosine
145
Q

What two amino acids have a pKa of 4?

A
  1. Aspartic acid 2. Glutamic acid
146
Q

What disease has a genetic deficiency in adenosine deaminase?

A

Severe combined immunodeficiency (SCID)

147
Q

What type of charge does the molecule have if the pH is greater than the pI (isoelectric point)?

A

A net negative charge

148
Q

In what disease is there a deficiency in hypoxanthine guanine phosphoribosyl transferase (HGPRT)?

A

Lesch-Nyhan syndrome

149
Q

What is the end product of purine catabolism?

150
Q

What enzyme is deficient in selective T cell immunodeficiency?

A

Purine nucleoside phosphorylase

151
Q

What substrate builds up in Tay-Sachs disease?

A

Ganglioside GM2

152
Q

On a Lineweaver-Burke plot, what type of binding has both plots crossing the y-axis in the same spot?

A

Competitive, reversible inhibition (Vmax is the same, increase Km)

153
Q

What toxin ADP-ribosylates via GS protein to increase CAMP?

A

Cholera toxin

154
Q

What vitamin derivatives are used for growth and differentiation of epithelium for reproductive and embryonic development?

155
Q

Light causes isomerization of what in the eyes?

A

11-cis-retinal to traps-retinal (activated rhodopsin)

156
Q

What are the two actions of calcitonin?

A
  1. Increases Ca2+ excretion from the kidney 2. Increases bone mineralization
157
Q

What causes an increase in bone mineralization and Cat+, as well as P04 absorption from the GI tract and kidney tubules?

158
Q

On the Lineweaver-Burke plot, what type of binding has both plots crossing the x-axis in the same spot?

A

Noncompetitive, reversible binding (decrease in Vmax; Km is same)

159
Q

What is the maximum rate possible with a given amount of enzyme?

160
Q

To what are intracellular glucose levels inversely related?

A

cAMP levels

161
Q

Does a saturated fatty acid have double bonds?

A

No; unsaturated fatty acids have double bonds

162
Q

What two factors cause PTH to be secreted?

A
  1. A decrease in blood Ca2+ 2. A decrease in PO4 concentrations
163
Q

What in the human genome differs in each individual that can serve as an identification marker?

A

RFLP-restriction fragment length polymorphism

164
Q

What test is used to identify HIV-positive patients?

A

ELISA-enzyme-linked immunosorbent assay

165
Q

What toxin ADP-ribosylates via G to increase cAMP?

A

Pertussis toxin

166
Q

What vitamin is essential for normal Ca2+ and P04 metabolism?

167
Q

What vitamin is deficient in a person who has impaired taste, night blindness, and increased risk for having an abortion?

168
Q

What bond does an endonuclease cleave?

A

3’, 5’ internal phosphodiesterase bond

169
Q

What protein separates base pairs and unwinds the DNA at the replication fork?

A

Helicase (It is an ATP-dependent enzyme.)

170
Q

What vitamin deficiency would cause liver necrosis and red blood cell fragility?

A

Vitamin E deficiency

171
Q

What protein catalyzes the formation of the last phosphodiester bond (PDE) between the Okazaki fragments to produce a continuous strand?

A

DNA ligase

172
Q

What is the hypochromic effect?

A

Increased absorption as DNA goes from double stranded to single stranded

173
Q

What technique uses DNA for analysis?

A

Southern blotting

174
Q

In what direction is a new DNA strand made?

A

5’ to 3’

175
Q

What enzyme has a 5’ to 3’ synthesis activity and a 3’ exonuclease activity?

A

DNA polymerase III

176
Q

What enzyme makes a double-stranded cut through DNA, needs ATP, and introduces negative supercoiling?

A

Topoisomerase II

177
Q

What eukaryotic DNA polymerase is used for: DNA replication?

A

a- and delta-polymerase

178
Q

What eukaryotic DNA polymerase is used for: Replication in mitochondria?

A

gamma-Polymerase

179
Q

What eukaryotic DNA polymerase is used for: DNA repair?

A

ß-Polymerase

180
Q

What is the orientation of the gene sequence strand?

A

5’ to 3’ (same as RNA)

181
Q

What is the location of the TATA box in procaryotes?

A

10 bases downstream

182
Q

What binds to the promoter region in procaryotes?

A

Sigma factor

183
Q

What enzyme has a 5’ to 3’ synthesis of the Okazaki fragments, 3’ exonuclease activity, and 5’ exonuclease activity?

A

DNA polymerase I

184
Q

What type of mutation has the same amino acid coded for, but with a different codonsequence?

A

Silent mutation

185
Q

At what position of the anticodon does the “wobble” hypothesis occur?

A

Position 1 of the anticodon (the 5’ end)- which is the same as position 3 of the codon (the 3’ end)

186
Q

What are the three “stop” codons?

A
  1. UAA 2. UAG 3. UGA
187
Q

What stops transcription in procaryotes?

A

Rho factor or a hairpin loop

188
Q

What are the three post-transcriptional modifications?

A
  1. 7-methyl guanine cap on the 5’ end 2. Addition of the poly(A) tail to the 3’ end 3. Removal of introns
189
Q

In what type of mutation is a different codon added, resulting in formation of a different amino acid?

A

Missense mutation

190
Q

What amino acid is attached to the 3’ end of the tRNA in eukaryotes?

A

Methionine

191
Q

What enzyme makes tRNA and the SsRNA?

A

RNA polymerase III

192
Q

What structure of a protein describes the interaction among subunits?

A

Quaternary structure

193
Q

What two amino acids require vitamin C for hydroxylation?

A
  1. Proline 2. Lysine
194
Q

What is determined by the secondary structure of an amino acid?

A

The folding of an amino acid chain

195
Q

Which mutation has a stop codon put in place of the previous codon?

A

Nonsense mutation

196
Q

What amino acid is attached to the 3’ end of the tRNA in prokaryotes?

A

f-Methionine

197
Q

What enzyme makes rRNA (barring the 5s subunit)?

A

RNA polymerase I

198
Q

What is the site of action of cycloheximide?

A

Peptidyl transferase (60S)

199
Q

What translation factor is blocked by erythromycin?

A

Elongation factore G (EF-G)

200
Q

What is the charge of the molecule if the pH is less than the pI (isoelectric point)?

A

A net positive charge

USMLE Buzzwords (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions