Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

USMLE COMPREHENSIVE REVIEW > D1201-1400 > Flashcards

D1201-1400 Flashcards

1
Q

Is the Lac operon activated or inactivated in the presence of both glucose and lactose?

A

Inactivated; glucose results in decreased cAMP levels and therefore blocks protein binding between cAMP and CAP.

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

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

A

Acetyl CoA, FADH2, and NADH

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

What is the rate-limiting enzyme on glycolysis?

A

Phosphofructokinase-1 and costs 1 ATP

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

What enzyme of heme synthesis is deficient in the autosomal dominant disorder acute intermittent porphyria?

A

Uroporphyrinogen-I synthase

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

What enzyme is blocked by disulfiram?

A

Aldehyde dehydrogenase

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

Deficiencies in what enzyme result in insoluble glycogen synthesis formation?

A

α-1, 6 transferase

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

What eukaryotic translation enzyme is associated with the following: • Initiation

A

eIF-2 in the P site

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

What eukaryotic translation enzyme is associated with the following: • Elongation

A

eEF-1

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

What eukaryotic translation enzyme is associated with the following: • Termination

A

No enzymes are needed. When the stop codon reaches the A site, it results in termination.

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

What AA undergoes N-glycosylation?

A

Asparagine

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

What is the pyrimidine intermediate that joins PRPP (5-Phosphoribosyl-1-Pyrophosphate)?

A

Orotic acid (purine metabolism)

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

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

A

Farnesyl pyrophosphate (FPP)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What AA is a phenol?

A

Tyrosine

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

What hormone is activated in adipose tissue when blood glucose levels decrease?

A

Hormone-sensitive lipase

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

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

A

2 NADPHs per acetyl CoA

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

What factors are needed for elongation in eukaryotes?

A

EF-1 and GTP

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

What purine base is contained in inosine monophosphate?

A

Hypoxanthine (remember, IMP is a precursor for AMP and GMP)

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

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

A

Aspartate and carbomoyl PO4-

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

What two requirements must be met for the Lac operon to be activated?

A

Lactose must be present and glucose must be absent

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

Name the phase of the eukaryotic cell cycle: • Period of cellular growth (translation and transcription) before DNA synthesis

A

G1 phase (gap 1)

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

Name the phase of the eukaryotic cell cycle: • Period of cellular growth (translation and transcription) after DNA synthesis

A

G2 phase (gap 2)

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

Name the phase of the eukaryotic cell cycle: • Period of DNA replication (preparing for mitosis)

A

S phase

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

Name the phase of the eukaryotic cell cycle: • Cells cease replicating (i.e., nerve cell)

A

G0 phase

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

True or false? RBCs anaerobically use glucose in both the well-fed and fasting states.

A

True. Remember, RBCs do not contain mitochondria, so they cannot metabolize aerobically.

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

What enzyme of the TCA cycle catalyzes the substrate level phosphorylation?

A

Succinyl CoA synthetase

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

What apoprotein on HDL activates lecithin-cholesterol acyltransferase (LCAT)?

A

apo A-1

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

What three AAs are used to synthesize the purine ring?

A
  1. Glycine 2. Aspartate 3. Glutamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How many ATPs are produced from cytoplasmic NADH oxidation using the glycerol phosphate shuttle?

A

2 ATPs by oxidative phosphorylation

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

What enzyme is deficient in patients with PKU?

A

Phenylalanine hydroxylase

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

What three steps of the TCA cycle generate NADH?

A
  1. Malate dehydrogenase 2. Isocitrate dehydrogenase 3. α-Ketoglutarate dehydrogenase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What two enzymes of heme synthesis are inhibited by lead?

A

ALA dehydrogenase and ferrochelatase

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

What enzyme, induced by insulin and activated by apo C-II, is required for chylomicron and VLDL metabolism?

A

Lipoprotein lipase

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

What is the most common genetic deficiency resulting in hemolytic anemia?

A

G-6-PD deficiency; pyruvate kinase deficiency is second.

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

Are the following conditions associated with a negative or positive nitrogen balance? • AA deficiency

A

Negative

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

Are the following conditions associated with a negative or positive nitrogen balance? • Growth

A

Positive

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

Are the following conditions associated with a negative or positive nitrogen balance? • Pregnancy

A

Positive

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

Are the following conditions associated with a negative or positive nitrogen balance? • Uncontrolled DM

A

Negative

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

Are the following conditions associated with a negative or positive nitrogen balance? • Starvation

A

Negative

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

Are the following conditions associated with a negative or positive nitrogen balance? • Infection

A

Negative

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

Are the following conditions associated with a negative or positive nitrogen balance? • Recovery from injury

A

Positive

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

Are the following conditions associated with a negative or positive nitrogen balance? • Kwashiorkor

A

Negative

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

Why is the liver unable to metabolize ketone bodies?

A

Hepatocytes lack the enzyme succinyl CoA acetoacetyl CoA transferase (thiophorase).

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

What toxin ADP-ribosylates via Gs protein to increase cAMP?

A

Cholera toxin

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

What two vitamins are inactivated when they come in contact with acetaldehyde?

A

Thiamine and folate

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

Name the end product or products: • Fatty acid synthesis

A

Palmitate

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

Name the end product or products: • Fatty acid oxidation

A

Acetyl CoA and propionyl CoA (in odd chain fatty acids)

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

What is the term for production of a DNA copy from an RNA molecule?

A

Reverse transcription

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

What two monosaccharides are produced when lactose is hydrolyzed?

A

Galactose and glucose

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

What mineral is required for cross-linking of collagen molecules into fibrils?

A

The enzyme lysyl oxidase requires Cu2+and O2 to function properly.

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

What blotting technique uses the following for analysis? • DNA

A

Southern blot

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

What blotting technique uses the following for analysis? • Protein

A

Western blot

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

What blotting technique uses the following for analysis? • RNA

A

Northern blot

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

How many high-energy bonds does the cycle of elongation cost?

A

Four high energy bonds, two from ATP in AA activation and two from GTP

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

What enzyme of purine synthesis is inhibited by allopurinol and 6-mercaptopurine?

A

PRPP aminotransferase

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

True or false? The urea cycle takes place in both the cytoplasm and the mitochondria.

A

True. Remember, carbamoyl phosphate synthetase and ornithine transcarbamoylase are mitochondrial enzymes.

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

What is the only fatty acid that is gluconeogenic?

A

Propionic acid

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

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

A

DNA polymerase I

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

In what organelle does the TCA cycle occur?

A

Mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Do genomic or cDNA libraries contain introns, exons, promoters, enhancers, and are they fragmented?

A

Genomic libraries are made from nuclear DNA, are fragmented, and contain all sequences found in the particular genome copied.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What enzyme is deficient in selective T cell immunodeficiency?

A

Purine nucleoside phosphorylase

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

True or false? Adipose tissue lacks glycerol kinase.

A

True. Adipose depends on glucose uptake for dihydroxyacetone phosphate (DHAP) production for triglyceride synthesis.

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

In what form is excess folate stored in the body?

A

N-5-methyl THF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the term for taking an mRNA molecule and arranging the AA sequence forming a protein?

A

Translation

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

What enzyme is blocked by hydroxyurea?

A

Ribonucleotide reductase

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

What protein carries free fatty acids to the liver?

A

Albumin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What substrate is built up in Niemann-Pick disease?

A

Sphingomyelin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

True or false? Methylation of bacterial DNA prevents restriction endonuclease from cutting its own chromosomes.

A

True. Restriction endonucleases cut only unmethylated DNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What two AAs have a pKa of 10?

A

Lysine and tyrosine

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

What is the only enzyme in the body that uses N-5-methyl folate?

A

Homocysteine methyl transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

How can you differentiate vitamin K from vitamin C deficiency by bleeding time and PT levels?

A

Vitamin K deficiency has normal bleeding time and increased PT, and vitamin C deficiency has increased bleeding time and normal PT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the term for a unit of DNA that encodes a particular protein or RNA molecule?

A

A gene (a rather simple definition but accurate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Is the coding or the template strand of DNA identical to mRNA (excluding the T/U difference)?

A

The coding strand is identical to mRNA, and the template strand is complementary and antiparallel.

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

What enzyme is deficient in acute intermittent porphyria?

A

Uroporphyrinogen I synthetase

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

What five cofactors and coenzymes are required by pyruvate dehydrogenase?

A
  1. TTP 2. Lipoic acid 3. Coenzyme A from pantothenate 4. NAD(H) (from niacin or tryptophan) 5. FADH2 (from riboflavin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What pattern of genetic transmission affects only M and has no M-to-M transmission, and mother is usually an unaffected carrier?

A

X-linked recessive

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

To what does aldose reductase convert galactose?

A

Galactitol

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

Name three purine bases that are not found in nucleic acids.

A

Xanthine, hypoxanthine, theophylline, theobromine, caffeine, and uric acid are all purines.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What water-soluble-vitamin deficiency is associated with cheilosis and magenta tongue?

A

Riboflavin (B2)

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

What is the precursor of all sphingolipids?

A

Ceramide

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

What three substances stimulate glycogenolysis?

A
  1. Ca2+ : calmodulin ratio 2. Epinephrine 3. Glucagon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is the primer for the synthesis of the second strand in production of cDNA from mRNA?

A

The hairpin loop made by reverse transcriptase at the 3’ end of the first strand is the primer.

82
Q

What factors are needed for elongation in prokaryotes?

A

EF-Tu or EF-ts and GTP

83
Q

What restriction endonuclease site is destroyed in sickle β-globin allele?

A

MstII; changing codon 6 (from A to T) destroys the restriction site.

84
Q

What complex is needed for propionyl CoA carboxylase?

A

Biotin, ATP, and CO2

85
Q

What enzyme catalyzes the reversible oxidative deamination of glutamate and produces the TCA cycle intermediate α-ketoglutarate?

A

Glutamate dehydrogenase

86
Q

What enzyme is deficient in congenital erythropoietic porphyria?

A

Uroporphyrinogen III cosynthase

87
Q

What is the drug of choice for treating a patient with hyperuricemia due to overproduction of uric acid?

A

Allopurinol

88
Q

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

A

Vmax

89
Q

From what do catalase, superoxide dismutase, and glutathione peroxidase defend the cell?

A

Production of oxygen free radicals

90
Q

What signals are used to direct an enzyme to a lysosome?

A

Phosphorylation of mannose residues

91
Q

What enzyme catalyzes the rate-limiting step of the urea cycle?

A

Carbamoyl phosphate synthetase I

92
Q

What liver enzyme, for triglyceride synthesis, converts glycerol to glycerol-3-phosphate?

A

Glycerol kinase

93
Q

What organ functions to keep blood glucose levels normal through both well-fed and fasting states and produces ketones in response to increased fatty acid oxidation?

A

Liver

94
Q

What pattern of inheritance does G-6-PD deficiency follow?

A

X-linked recessive

95
Q

What is the term for conversion of a dsDNA molecule to the base sequence of an ssRNA molecule?

A

Transcription (C comes before L in the alphabet, and transCription comes before transLation)

96
Q

Via what cell surface receptor does HDL cholesterol from the periphery enter hepatoceles?

A

Scavenger receptor (SR-B1)

97
Q

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

A

Carnitine acyl CoA transferase II

98
Q

What enzyme is blocked by 5-FU?

A

Thymidylate synthetase

99
Q

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

A

Gilbert’s syndrome

100
Q

What AA has a pKa of 13?

A

Arginine

101
Q

What X-linked recessive disorder is characterized by hyperuricemia, spastic cerebral palsy, mental retardation, and self-mutilation?

A

Lesch-Nyhan syndrome

102
Q

How many ATPs per glucose are generated from glycolysis in RBCs?

A

2 ATPs, because RBCs use only anaerobic metabolism.

103
Q

What enzyme catalyzes the rate-limiting step in glycogenolysis?

A

Glycogen phosphorylase

104
Q

Would a G-C or an A-T rich dsDNA sequence have a higher melting point? Why?

A

G-C rich sequences, because they have 3 hydrogen bonds, where A-T has 2 hydrogen bonds, resulting in higher melting points.

105
Q

As what AAs do muscles send nitrogen to the liver?

A

Alanine and glutamine

106
Q

What sphingolipid cannot be produced without sialic acid and amino sugars?

A

Ganglioside

107
Q

What happens to affinity if you increase Km?

A

Affinity decreases; they are inversely proportional.

108
Q

What type of bilirubin is found in neonatal jaundice?

A

Indirect or unconjugated

109
Q

What two AAs do not have more than one codon?

A

Methionine (start) and tryptophan are the only two AAs with only one codon.

110
Q

What bonds are broken by exonucleases?

A

External 3’, 5’ PDE bonds

111
Q

How can a genetic deficiency of carbamoyl phosphate synthetase be differentiated from an ornithine transcarbamoylase deficiency?

A

Uracil and orotic acid levels increase with ornithine transcarbamoylase deficiency and are normal in carbamoyl phosphate synthetase deficiency.

112
Q

Name the lipoprotein based on the following characteristics. • apo E

A

IDL

113
Q

Name the lipoprotein based on the following characteristics. • apo B-100

A

LDL

114
Q

Name the lipoprotein based on the following characteristics. • apo E, apo B-100, apo C-II

A

VLDL

115
Q

Name the lipoprotein based on the following characteristics. • apo A-1, apo E, apo C-II

A

HDL

116
Q

Name the lipoprotein based on the following characteristics. • apo E, apo C-II, apoB-48

A

Chylomicrons

117
Q

True or false? There is no hormonal control to the TCA cycle.

A

True. The energy status of the cell dictates if the cycle is running or relaxing.

118
Q

What are the three tissues where triacylglycerols are produced?

A
  1. Liver 2. Muscle 3. Adipose tissue
119
Q

What toxin ADP-ribosylates via Gi to increase cAMP?

A

Pertussis toxin

120
Q

What enzyme catalyzes the rate-limiting step in heme synthesis?

A

δ-ALA synthase

121
Q

What cycle is responsible for converting to glucose in the liver the lactate produced in the RBCs?

A

Cori cycle

122
Q

What enzyme is used to remove the hairpin loop during production of cDNA from mRNA?

A

S1 nuclease

123
Q

Does a saturated fatty acid have double bonds?

A

No, unsaturated fatty acids have double bonds.

124
Q

What pyrimidine base is found • Only in RNA?

A

Uracil

125
Q

What pyrimidine base is found • Only in DNA?

A

Thymine

126
Q

What pyrimidine base is found • In both DNA and RNA?

A

Cytosine

127
Q

What two AAs require vitamin C for hydroxylation?

A

Proline and lysine

128
Q

What is the only organ in the body that can produce ketone bodies?

A

The liver (in the mitochondria)

129
Q

What determines the rate of reaction?

A

The energy of activation

130
Q

What is the term for the number of trinucleotide repeats increasing with successive generations and correlating with increased severity of disease?

A

Anticipation, associated with fragile X syndrome; Huntington’s disease is also associated with a decrease in onset of age.

131
Q

What enzyme is blocked by methotrexate/ trimethoprim?

A

Dihydrofolate reductase

132
Q

What fructose metabolism enzyme is deficient in patients with vomiting, apathy, diarrhea, jaundice, proximal renal tubular acidosis, hypoglycemia, and hyperuricemia?

A

Aldolase B deficiencies are treated by eliminating fructose from the diet.

133
Q

What enzyme catalyzes the rate-limiting step in purine synthesis?

A

PRPP aminotransferase

134
Q

What water-soluble-vitamin deficiency is associated with poor wound healing, easy bruising, bleeding gums, anemia, and painful glossitis?

A

Vitamin C

135
Q

What three substrates control the enzyme PEPCK for the conversion of oxaloacetate (OAA) to pyruvate in the cytoplasm?

A
  1. Cortisol (stimulates PEPCK) 2. Glucagon 3. GTP
136
Q

What genetic defect is characterized by coarse facial features, gingival hyperplasia, macroglossia, psychomotor and growth retardation, club foot, claw hand, cardiorespiratory failure, and death in the first decade of life?

A

I-cell disease is a result of a genetic defect affecting the phosphorylation of mannose residues.

137
Q

What two glycolytic enzymes catalyze the substrate-level phosphorylations?

A

3-Phosphoglycerate kinase and pyruvate kinase; this produces two ATPs per enzyme (total four ATPs)

138
Q

What pathway uses HMG CoA synthetase in the cytoplasm?

A

Cholesterol biosynthesis

139
Q

Where in the body is heme converted to bilirubin?

A

RES(Reticular endothelial system)

140
Q

What protein is required by prokaryotic RNA polymerases to initiate transcription at the promoter region of DNA?

A

Sigma factor

141
Q

What enzyme catalyzes the rate-limiting step in pyrimidine synthesis?

A

Aspartate transcarbamylase

142
Q

What are the two actions of calcitonin?

A

It increases Ca2+ excretion from the kidney and increases bone mineralization.

143
Q

What enzyme of the purine salvage pathway is deficient in the following? • Selective T-cell immunodeficiency

A

Purine nucleoside phosphorylase

144
Q

What enzyme of the purine salvage pathway is deficient in the following? • SCID

A

Adenosine deaminase

145
Q

What enzyme of the purine salvage pathway is deficient in the following? • Lesch-Nyhan syndrome

A

HGPRT

146
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

147
Q

What is the primary end product of pyrimidine synthesis?

A

UMP

148
Q

What pyrimidine base is produced by deaminating cytosine?

A

Uracil

149
Q

What AA is classified as basic even though its pK is 6.5 to 7?

A

Histidine, because of the imidazole ring found in the R group, is basic.

150
Q

What enzyme is deficient in hereditary protoporphyria?

A

Ferrochelatase

151
Q

What elongation factor is inactivated by ADP ribosylation, preventing translation?

A

eEF-2 is the site where Pseudomonas and Diphtheria toxins work.

152
Q

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

A

Omega-3; linoleic is omega-6

153
Q

How many ATPs per glucose are generated in glycolysis?

A

38 ATPs if aerobic, 2 ATPs if anaerobic (36 ATPs[malate shuttle] + 4 ATPs[Glycolysis] - 2 ATPs[phosphorylate glucose] = 38 ATPs)

154
Q

Name the three ketone bodies.

A

Acetoacetate, acetone, and β-hydroxybutyrate

155
Q

What three bases are pyrimidines?

A
  1. Cytosine 2. Uracil (only in RNA) 3. Thymidine
156
Q

Name the RNA subtype based on the following: • The most abundant form of RNA in the cell

A

rRNA

157
Q

Name the RNA subtype based on the following: • Found only in the nucleus of eukaryotes and functions to remove introns from mRNA

A

snRNA

158
Q

Name the RNA subtype based on the following: • Only type of RNA that is translated

A

mRNA

159
Q

Name the RNA subtype based on the following: • Carries AA to the ribosome for protein synthesis

A

tRNA

160
Q

Name the RNA subtype based on the following: • RNA molecules with enzymatic activity

A

Ribozymes

161
Q

Name the RNA subtype based on the following: • Found only in the nucleus of eukaryotic cells and are precursors of mRNA

A

hnRNA

162
Q

What enzyme is deficient in the following glycogen storage disease? • von Gierke’s disease

A

Glucose-6-phosphatase

163
Q

What enzyme is deficient in the following glycogen storage disease? • Pompe’s disease

A

Lysosomal α-1, 4-glucosidase

164
Q

What enzyme is deficient in the following glycogen storage disease? • McArdle’s disease

A

Muscle glycogen phosphorylase

165
Q

What enzyme is deficient in the following glycogen storage disease? • Hers’ disease

A

Hepatic glycogen phosphorylase

166
Q

In prokaryotes, what is the term for a set of structural genes that code for a select group of proteins and the regulatory elements required for the expression of such gene?

A

Operon

167
Q

What are the two most common AAs found in histones?

A

Lysine and arginine

168
Q

What five pathways use SAM (S-adenosylmethionine) as the methyl donor?

A
  1. Epinephrine synthesis 2. Phosphatidyl choline 3. Creatine 4. Methylation of cytosine 5. N-methyl cap of mRNA
169
Q

What complex of the ETC contains Cu2+?

A

Complex 4

170
Q

How many ATPs per glucose are produced by pyruvate dehydrogenase?

A

6 ATPs (remember 2 pyruvates per glucose are produced, and 2 NADHs result from production of acetyl CoA, so 6 ATPs)

171
Q

What is the size of the prokaryotic ribosome?

A

70S ribosomes in prokaryotes and 80S ribosomes in eukaryotes

172
Q

What type of fatty acid is associated with a decrease in serum triglycerides and cardiovascular disease?

A

Omega-3 fatty acids

173
Q

What disease is produced by a deficiency in the enzyme tyrosinase?

A

Albinism. Tyrosine is converted to melanin by the enzyme tyrosinase.

174
Q

In what form are triglycerides sent to adipose tissue from the liver?

A

VLDLs

175
Q

What determines the rate of a reaction?

A

The energy of activation (Ea)

176
Q

What is the rate-limiting enzyme of the HMP shunt?

A

G-6-PD

177
Q

What vitamin is necessary for the transfer of one amino group from a carbon skeleton to another?

A

Pyridoxal phosphate is derived from vitamin B6 and is needed to transfer the amino groups of one carbon skeleton to another.

178
Q

What is the only sphingolipid that contains choline and PO4?

A

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

179
Q

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

A

DNA ligase

180
Q

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

A

Nephrotoxic oxylate stones

181
Q

What water-soluble-vitamin deficiency may result from eating raw eggs?

A

Biotin (only if eaten in large quantities)

182
Q

Regarding the Lac operon, for what do the following genes code? • Z gene

A

β-Galactosidase

183
Q

Regarding the Lac operon, for what do the following genes code? • Y gene

A

Galactoside permease

184
Q

Regarding the Lac operon, for what do the following genes code? • I gene

A

Lac repressor protein

185
Q

Regarding the Lac operon, for what do the following genes code? • A gene

A

Thiogalactoside transacetylase

186
Q

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

A

2, 4-Dinitrophenol

187
Q

1-α-Hydroxylase activity is increased in response to what two physiologic states? (hint: think of vitamin D activity)

A

Hypocalcemia and hypophosphatemia

188
Q

What is the major ketone body produced during alcoholic ketoacidosis?

A

β-Hydroxybutyrate

189
Q

What enzyme catalyzes the rate-limiting step in the TCA cycle?

A

Isocitrate dehydrogenase

190
Q

Name the pattern of genetic transmission characterized thus: both M and F are affected; M may transmit to M; each generation has at least one affected parent; and one mutant allele may produce the disease.

A

Autosomal dominant

191
Q

What bonds are broken by endonucleases?

A

Internal 3’, 5’ PDE bonds

192
Q

Name the GLUT transporter based on the following: • Found in liver and pancreatic β-cells

A

GLUT 2

193
Q

Name the GLUT transporter based on the following: • Found in skeletal muscle and adipose tissues

A

GLUT 4

194
Q

Name the GLUT transporter based on the following: • Found in most tissues, including brain and RBCs

A

GLUT 3 and 4

195
Q

What enzyme catalyzes the rate-limiting step in fatty acid oxidation?

A

Carnitine acyltransferase-I

196
Q

What enzyme of the TCA cycle also acts as complex II of the ETC?

A

Succinate dehydrogenase

197
Q

What is the term for chemicals that keep the pH constant despite the formation of acids and bases during metabolism?

A

Buffers (remember that buffers are best when they are used in a pH range near its pK)

198
Q

In the mitochondria, what complex is needed for pyruvate carboxylase to catalyze the reaction from pyruvate to OAA?

A

Biotin, ATP, and CO2

199
Q

How many ATPs are produced from cytoplasmic NADH oxidation using the malate shuttle?

A

3 ATPs by oxidative phosphorylation

200
Q

What is the rate-limiting step of the following? • Fatty acid synthesis

A

Acetyl CoA carboxylase

USMLE COMPREHENSIVE REVIEW (8 decks)

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