Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry-Exam 2 > Moyzis > Flashcards

Moyzis Flashcards

0
Q

Name the purines

A

Adenine and Guanine

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

About what mass of AA is used for protein synthesis in a day? For other molecules?

A

400 g/day; 30 g/day

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

Which nitrogenous bases have two rings?

A

Purine

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

Name the pyrimidines

A

Cytosine, Uracil, Thymine

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

Which nitrogenous bases have a single ring?

A

Pyrimidine

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

Which is more stable ribose or 2-deoxyribose?

A

2-deoxyribose

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

What are nucleosides?

A

Pentose sugar plus base

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

What is responsible for the negative charge associated with DNA?

A

Phosphate groups

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

How do we name nucleotides?

A

Ribonucleoside 5’-mono/di/triphosphate

E.g. Adenosine 5’-triphosphate

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

Nucleotides are?

A

Composed of a nitrogenous base, a pentose monosaccharide, and one/2/3 phosphate groups

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

T or F: Donated atoms of a nitrogenous base are added to a preformed ribose 5’-phosphate

A

T

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

Purine rings contain atoms donated from?

A

Formate, Glutamine (Amide groups), Aspartate, Glycine, and Carbon dioxide

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

What is the first step of purine synthesis?

A

Ribose 5-phosphate is made into 5-Phosphoribosyl-1-pyrophosphate (PRPP)

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

PRPP enzyme?

A

PRPP synthetase. Needs magnesium ion and ATP

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

How is PRPP synthetase regulated?

A

Positive: Inorganic phosphate
Negative: Purine ribonucleotides (end product inhibition)

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

What is PRPP made into?

A

5’-Phosphoribosylamine; made by Glutamine phosphoribosyl pryrophosphate amidotranferase; consumes Glutamine and Water Releasing Glutamate and Pyrophosphate. In presence of magnesium

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

What step is the commit step for purine synthesis?

A

PRPP to 5’-Phosphoribosylamine

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

What is the parent purine nucleotide?

A

Inosine monophosphate (takes 4 ATP to make)

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

How many ATP are required to make IMP?

A

4 ATP

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

What is the mechanism of sulfonamides?

A

Block synthesis of folic acid. Since purine synthesis requries THF (a folic acid derivative) as a coenzyme, the sulfa drugs inhibit this pathway. Doesnt harm human cells since we just eat folate

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

T or F: Humans can synthesize folic acid

A

F

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

What is the mechanism of methotrexate?

A

Structural analog to folic acid used in cancer. Interferes with nucleotide synthesis. Hurts healthy cells too like bone marrow, hair follicles, GI tract

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

What energy source is needed to make AMP?

A

GTP

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

What energy source is needed to make GMP?

A

ATP

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

What inhibits IMP to AMP pathway?

A

AMP levels

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

What inhibits IMP to GMP pathways?

A

GMP levels

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

What is mycophenolic acid?

A

A potent reversible inhibitor of IMP dehydrogenase which prevents GMP production (promising in graft rejection prevention). Deprives rapidly producing cells of a key nucleic acid

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

What is the function of base-specific nucleoside monophosphate kinases?

A

Converts AMP and ATP to ADP and back. Balances M,D,T forms

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

What does adenylate kinase do?

A

Balances AMP, ADP, and ATP levels

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

What are nucleoside diphosphate kinases?

A

Converts between di and tri forms only

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

What is the source of phosphate in the nucleoside phosphate conversions?

A

ATP almost exclusively due to high levels

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

T or F: The pyrimidine ring is made before being attached to the ribose 5-phosphate

A

T; this is distinct to the piecewise method for purines

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

What are the sources for the pyrimidine ring?

A

Glutamine, carbon dioxide, and aspartic acid

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

What is the first step of pyrimidine synthesis?

A

Formation of carbamoyl phosphate from Glutamine, HCO3-, and 2 ATP via Carabmoyl phosphate synthetase II to produce carabmoyl phosphate, glutamate, 2 ADP and 1 Pi

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

What enzyme makes carbamoyl phosphate?

A

Carbamoyl phosphate synthetase

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

What regulates carabmoyl phosphate synthetase?

A

Negative: UTP
Positive: ATP and PRPP

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

Carbamoyl phosphate is converted to what first ring form?

A

Dihydroorotate

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

T or F: The first three steps of pyrmidine synthesis is catalyzed by three different domains on the same polypeptide

A

T

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

T or F: Enzymes in pyrimidine synthesis are from mitochondria genes

A

T

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

Dihydroorotate is made into?

A

Orotate

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

Orotate is made into?

A

OMP via PRPP

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

OMP is made into?

A

UMP (Uridine 5’-monophosphate)

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

T or F: Dihydroorotate is made into OMP and OMP to UMP by the same protein with different domains

A

T

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

What is orotic aciduria?

A

Orotic acid in urine due to genetic defect in the last two steps

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

How is UTP made into CTP?

A

Via CTP synthestase and ATP, with glutamine to glutamate as the source of nitrogen

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

What is the source of nitrogen for UTP to CTP?

A

Glutamine

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

What is the parent molecule for pyrimidines?

A

UMP

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

How is 2’-deoxyribonucleotide formed?

A

Via ribonucleotide reductase

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

What is the structure of ribonucleotide reductase?

A

Two identical B1, Two identical B2 subunits which are specific for ADP, GDP, CDP, and UDP

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

Describe the allosteric activity of Ribonucleotide reductase

A

Binding of dATP inhibits enzyme and prevents reduction of any NDPs effectively preventing DNA syntehsis

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

What controls the substrate specificity of ribonucleotide reductase?

A

Binding of NTPs to a substrate site

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

What is adenosine deaminase deficiency?

A

Excess dATP which prevents DNA synthesis

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

How is dTMP made?

A

From dUMP via thymidylate synthetase

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

What is the mechanism of 5-fluorouracil?

A

Thymine analog that inhibits thymidylate synthase as an antitumor agent. 5-fluorouracil to 5-FdUMP which is permanent bound.

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

What is the “suicide” inhibitor?

A

5-fluorouracil

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

dUMP is made to dTMP by the oxidation of what molecule?

A

THF (tetrahydrofolate) to dihydrofolate (DHF)

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

How is DHF reduced?

A

Via dihydrofolate reductase to THF

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

T or F: Methotrexate inhibits both purine synthesis as well as dUMP to dTMP

A

T

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

How does methotrexate inhibit pyrimidine synthesis?

A

Methotrexate inhibits dihydrofolate reductase (DHF to THF) which prevents dUMP to dTMP

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

How are purine nucleotides degraded?

A

In the small intestine into uric acid

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

What is gout?

A

Excess uric acid in the blood

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

How are pyrimidine nucleotides degraded?

A

Opened and degraded to beta-alanine and beta-aminoisobutyrate which are precursors for acetyl-CoA and succinyl-CoA respectively

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

How is uric acid produced?

A

Amino is removed from AMP to IMP. IMP and GMP are converted to inosine and guanosine. Inosine and guanosine are converted to bases. Guanine is deamined to xanthine. Hypoxanthine is oxidized to xanthine.
Xanthine is oxidized to uric acid

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

What is guanine deaminated to?

A

Xanthine

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

What is inosine converted to?

A

Hypoxanthine

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

What does allopurinol do?

A

Prevents conversion of xanthine to uric acid

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

T or F: Adenine deaminase deficiency has been treated successfully by gene therapy

A

T

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

What enzyme does allopurinol inhibit?

A

Xanthine oxidase

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

What two enzymes are responsible for purine salvage?

A

Adenine Phosphoribosyltransferase (APRT) and hypo-xanthine-guanine phosphoribosyltransferase (HPRT)

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

What cofactors do APRT and HPRT need?

A

PRPP (taken to pyrophosphate)

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

T or F: Purine salvage is irreversible

A

T

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

HPRT takes hypoxanthine to?

A

IMP

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

HPRT takes guanine to?

A

GMP

73
Q

APRT takes adenine to?

A

AMP

74
Q

What is Lesch-Nyhan syndrome?

A

X-chromosome linked recessive disorder leading to complete deficency of HPRT leading to increased PRPP and decreased IMP and GMP. Uric acid is highly produced leading to severe gout and self-mutiliation

75
Q

What is another name for epinephrine?

A

Adrenalin

76
Q

Name three catecholamines

A

Dopamine, norephinephrine, epinephrine

77
Q

The catecholamines do?

A

Degredation of glycogen and increase blood pressure and heart output

78
Q

What is serotonin?

A

5-hydroxytryptamine and plays role in pain, affective disoreders, regulation of sleep, temperature, and blood pressure

79
Q

The catecholamines are derived from what ?

A

Tyrosine

80
Q

What AA can be made into tyrosine?

A

Phenylalanine

81
Q

Tyrosine is hydroxylated to?

A

DOPA

82
Q

DOPA is decarboxylated to?

A

Dopamine

83
Q

Dopamine can be hydroxylated to?

A

Norepinephrine

84
Q

What are MAOs?

A

Oxidatively demainate catecholamines (monoamine oxidases)

85
Q

What are MAO inhibitors?

A

Block MAO enzyme raising NT levels (used in anti-depression meds)

86
Q

What NT is given to Parkinson’s patients?

A

L-dopa

87
Q

What is methylphenidate?

A

Blocks reuptake by dopamine transporters leading to synapse stimulus

88
Q

What AA is the progenitor to serotonin?

A

Tryptophan

89
Q

How is Tryptophan made into serotonin?

A

Hydroxylated and then decarboxylated

90
Q

Low levels of serotonin is associated with?

A

depression

91
Q

How to paxil and prozac work?

A

Block serotonin transporters and increase synaptic serotonin levels

92
Q

T or F: Phenylalanine and Tryptophan are essential AA

A

TRUE (crazy)

93
Q

Nucleotides are composed of?

A

Nitrogenous base, pentose monosaccharide, and 1/2/3 phosphate groups

94
Q

How do T and U differ in structure?

A

T has a methyl group

95
Q

What is a nucleoside?

A

Pentose and base

96
Q

What are the five nucleoside names?

A

Adenosine, guanosine, cytidine, uridine, thymidine

97
Q

What inhibits PRPP synthetase?

A

AMP, GMP, and IMP

98
Q

What is the committed step in purine biosynthesis?

A

PRPP synthetase taking Ribose 5-phosphate to PRPP

99
Q

What is another name for PRPP synthetase?

A

Glutamine phosphoribosyl pryophosphate amidotransferase

100
Q

What controls the rate of reaction for production of PRPP?

A

PRPP levels (far below Km so small changes give proportional change in rate of reaction)

101
Q

How many ATP are required to take PRPP to IMP?

A

4

102
Q

What folic acid analog is required in two steps of purine synthesis?

A

N10-formyltetrahydrofolate

103
Q

What does trimethoprim do?

A

Folate analog that selective inhibits bacterial dihydrofolate reducatase

104
Q

T or F: AMP and GMP production are self-inhibiting (feedback)

A

T

105
Q

T or F: MPA is uncompetitive inhibitor

A

T

106
Q

T or F: Interconversions of phosphate lengths for nucleotides are all powered by ATP

A

T

107
Q

Which are more specific: Base-specific nucleoside monophosphate kinases or nucleoside diphosphate kinase

A

First one, however second one only works on DP nucleosides

108
Q

What is the source of ribose 5-phosphate in pyrimidine synthesis?

A

PRPP

109
Q

What two AA are needed for both purine and pyrimidine synthesis?

A

Glutamine and aspartic acid

110
Q

What is the regulated step of pyrimidine synthesis?

A

Synthesis of carbamoyl phosphate from glutamine and CO2 via carbamoyl phosphate synthetase (CPS) II.

111
Q

What regulates CPS II?

A

Negative: UTP
Positive: ATP and PRPP

112
Q

T of F: CPS requires biotin cofactors

A

F

113
Q

Carbamoyl phosphate is made into?

A

Carbamoylasparate by asparate transcarbamoylase

114
Q

Where is orate enzyme located?

A

Inner mitochondrial membrane

115
Q

What three enzymes are on the same multicatalytic polypeptide in pyrimidine synthesis?

A

CPS II, aspartate transcarbamoylase, dihydroorotase

116
Q

Orotate is made into?

A

OMP by orotate phosphoribosyl transferase converting PRPP to PP

117
Q

OMP is made into?

A

UMP by OMP decarboxylase losing CO2

118
Q

T or F: OMP decarboxylase and Orotate phosphoribosyl transferase are on the same protein

A

T

119
Q

UTP is made to CTP by?

A

CTP synthetase

120
Q

What provides the nitrogen in the UTP to CTP step?

A

Glutamine

121
Q

2’-deoxyribonucleotides are produced from what two things?

A

Ribonucleodtide diphosphates and ribonucleotide reductase (enzyme)

122
Q

What happens when dATP binds to allosteric sites on ribonucleotide reductase?

A

Stops overall catalytic activity (adenosine deaminase deficiency leads to toxicity)

123
Q

dUMP is converted to what by what enzyme?

A

dTMP by thymidylate synthetase

124
Q

What donates methyl group for dUMP to dTMP?

A

THF which is oxidized to DHF

125
Q

T or F: Methotrexate affects both purine and dUMP to dTMP synthesis

A

T

126
Q

T or F: Dietary DNA is used to a large extent in synthesis of cellular DNA

A

F

127
Q

Dietary purines are converted to…

A

Uric acid by intestinal mucosal cells

128
Q

Dietary pyrimidines are made into…?

A

Opened and degraded into soluble products releasing ammonia and CO2

129
Q

The rate limiting enzyme in DOPA production is?

A

tyrosine hydroxylase

130
Q

What inactivates catecholamines besides MAOs?

A

COMTs catechol-O-methyl-transferase

131
Q

Approximate size of genome of human? Percent coding proteins? Repetitive? Gene number?

A

3000 Mb, 1.5 percent, >50 percent, ~25,000

132
Q

Average exon, size, polypeptide for a gene?

A

9, 122 bp, 500 AA

133
Q

RNA and DNA are degraded to what and where?

A

Oligonucleotides in the small gut

134
Q

What happens to oglionucleotides in the gut?

A

Absorption into intestinal mucosal cells to be degraded into free bases

135
Q

Hyperuricemia is associated with what degredation pathway?

A

Purine degradation leading to uric acid

136
Q

What does idiopathic mean?

A

No known cause

137
Q

What is alternative splicing?

A

mRNA is spliced into different processed forms introns/exons

138
Q

T or F: Human exons are comparitively short

A

T

139
Q

T or F: Human introns are short comparitively

A

F; they are long

140
Q

T or F: Larger genes are more likely to be mutated

A

T (doesn’t mean deadly, in fact most small genes are deadly if mutated)

141
Q

T or F: Human genes have many copies

A

T

142
Q

What percentage of genes have known function?

A

Only 50 percent!

143
Q

Describe what is meant about genes within genes?

A

Sense and Anti-sense strands have different genes on them in the same gene (exons)

144
Q

Deletion/mutation in NF1 causes?

A

Neurofibromatosis

145
Q

50% of the genome is repetitive, what makes this up?

A

Tandem repeats at centromeres and telomeres as well as Interspersed repeats (Alu and L1)

146
Q

Tandem repeats are often found near what on the chromosome?

A

Centromere (very heterochromatic)

147
Q

What is the sequence of human telomere?

A

TTAGGG

148
Q

Telomerase solves what problem in regards to DNA replication?

A

End replication problem

149
Q

What happens to the telomere with age?

A

Shortens

150
Q

What is dyskeratosis congenita?

A

Mutation in RNA portion of telomerase

151
Q

What is the size and count of Alu?

A

300 bp, more than a million copies

152
Q

What is the size and count of L1?

A

7kb, more than 100,000 copies (many truncated)

153
Q

T or F: Alu and L1 are retroposons

A

T (move through reverse transcriptase mechanism)

154
Q

Describe the chain reaction of L1?

A

Brings its own promoter and codes for endonuclease and reverse transcriptase so they are coded in again and again

155
Q

T or F: L1 genes are used to fill DSB

A

T

156
Q

T or F: L1 Reverse Tx can be used to make copies of any gene

A

T (pseduogene)

157
Q

T or F: Movement of transposons is a major source of new mutation in humans

A

T

158
Q

What is VJ rejoining?

A

A major source of diversity in antibodies due to transposon recombinase

159
Q

What is genomic imprinting?

A

Maternal or Paternal allele is silenced by methylation

160
Q

T or F: Methylation is reset in the germline

A

T

161
Q

T or F: Due to X-silencing, female cells are mosaics

A

T

162
Q

The maternal equivalent of Prader-Willi syndrome is?

A

Angelman syndrome

163
Q

What is the out of africa hypothesis?

A

Modern humans evolved out of Africa 50kyrs ago and migrated throughout world

164
Q

What is the mutation rate and how is it used anthropologically?

A

3 x 10^-9 mutations/bp/generation, molecular clock

165
Q

SNPs tell us?

A

Each SNP tells us age of DNA

166
Q

Allele variation tells us?

A

Spelling of the gene are genetic markers

167
Q

A bottleneck leads to what?

A

Low genetic diversity

168
Q

Humans are not very genetically diverse because of a ?

A

Genetic bottleneck

169
Q

Humans in Africa are roughly how old? Europe? Asia? America?

A

100 kyrs, 40kyrs, 50-70 kyrs, 15-30 kyrs

170
Q

Roughly how many years per generation?

A

20 yrs

171
Q

Which population has the greatest genetic diversity?

A

African populations, then Asian and European, then Americans

172
Q

T or F: Human genome has remnants of other species like neanderthals ?

A

T (meaning they mated while migrating)

173
Q

T or F: SNPs have distinct geographic bias

A

T

174
Q

DRD4 7R is associated with what?

A

Blunted response to dopamine and is associated with ADHD (highly prevalent in the Americas, not common in Asia for example)

175
Q

Where is lactase gene most likely found?

A

Populations that ate milk (europe and Middle East)

176
Q

What is sickle cell disease?

A

Common in areas where malaria is common

177
Q

What is heterozygote advantage?

A

Individuals with one of each allele has an advantage (sickle cell)

178
Q

What is the disease gene? Do we have it?

A

We do not have genes for disease, we have altered genes that lead to disease

179
Q

What is the genome wide association study approach?

A

Use of genome level examination to tell us that a functional variation must exist without telling us function. Then we can study these to see what they are

Biochemistry-Exam 2 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions