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Quick Biochemistry - Nucleic Acids (Section 1)

1
What components combine to form a nucleoside?
Answer
(B)
A purine or pyrimidine base and a sugar
2
Which of the following best describes the composition of a nucleotide?
Answer
(B)
A purine and pyrimidine base, a sugar, and phosphorous
3
Which of the following is classified as a purine nucleotide?
Answer
(A)
AMP
4
Which option represents a pyrimidine nucleotide?
Answer
(C)
CMP
5
Adenine is also known as:
Answer
(A)
6-Amino purine
6
What is the other name for 2, 4-Dioxypyrimidine?
Answer
(C)
Uracil
7
What is the chemical designation for guanine?
Answer
(B)
2-Amino-6-oxypurine
8
In what units are the concentrations of nucleotides and nucleic acids frequently expressed?
Answer
(D)
OD at 260 nm
9
Which pyrimidine nucleotide is involved in high-energy intermediate reactions?
Answer
(C)
UDPG
10
In a nucleotide, what carbon position on the pentose molecule is involved in an ester bond with phosphate?
Answer
(D)
C₅
11
What molecule results from the combination of uracil and ribose?
Answer
(A)
Uridine
12
Which nucleotide is most prevalent in a free state within animal cells?
Answer
(A)
ATP
13
Approximately what is the average intracellular concentration of ATP in a mammalian cell?
Answer
(A)
1 mM
14
Which base is present in messenger RNA but absent in deoxyribonucleic acid?
Answer
(D)
Uracil
15
What is the function of 'Caps' in an RNA molecule?
Answer
(B)
Are unique to eukaryotic mRNA
16
How does prokaryotic mRNA differ from eukaryotic mRNA?
Answer
(A)
Can be polycistronic
17
What is the approximate size range of small stable RNA molecules?
Answer
(C)
90-300 nucleotides
18
What is the approximate range of small stable RNAs found within a single cell?
Answer
(C)
1,00,000-10,00,000
19
What is the approximate molecular weight of heterogenous nuclear RNA (hnRNA)?
Answer
(A)
More than 107
20
In RNA, why isn't the guanine content always equal to cytosine, and adenine always equal to uracil?
Answer
(A)
Single strand molecule
21
Which nitrogenous base is found in RNA?
Answer
(B)
Uracil
22
Which of the following is NOT a component of RNA?
Answer
(C)
Thymine
23
What type of sugar is found in RNA?
Answer
(C)
Ribose
24
Which statement accurately describes base pairing in an RNA molecule?
Answer
(D)
Guanine content does not necessarily equal its cytosine content.
25
In which type of RNA are methylated purines and pyrimidines typically found?
Answer
(C)
tRNA
26
Where is Thymine typically found?
Answer
(A)
tRNA
27
What is the approximate number of nucleotides in a tRNA molecule?
Answer
(C)
75
28
In a typical cell, what is the minimum number of different tRNA molecules present?
Answer
(B)
20
29
What shape does a tRNA molecule resemble?
Answer
(C)
Clover leaf
30
In tRNA molecules, the CCA sequence is always located at the:
Answer
(A)
3' Termini
31
What is the basis for classifying Transfer RNAs?
Answer
(D)
Extra arm
32
Which modified base is found in the D arm of a tRNA molecule, giving it its name?
Answer
(A)
Uridine
33
How many base pairs are typically found in the acceptor arm of a tRNA molecule?
Answer
(B)
7 Base pairs
34
How many base pairs does the anticodon arm of a tRNA molecule typically possess?
Answer
(A)
5 Base pairs
35
What sequence is typically found in the TΨC arm of a tRNA molecule?
Answer
(A)
T, pseudouridine and C
36
Who put forth the double helical structure model of DNA?
Answer
(C)
Watson and Crick
37
Which of the following is NOT found in DNA?
Answer
(C)
Uracil
38
What is the type of sugar molecule found in DNA?
Answer
(A)
Deoxyribose
39
DNA segments with a high concentration of A-T pairs are stabilized by how many hydrogen bonds?
Answer
(B)
2 Hydrogen bonds
40
Which statement accurately describes the base composition in a DNA molecule?
Answer
(D)
Guanine content equals cytosine content
41
DNA with a high proportion of G-C pairs tend to have what characteristic regarding hydrogen bonds?
Answer
(C)
3 Hydrogen bonds
42
Given that DNA carries an organism's genetic code, what can be logically inferred about its base composition across different tissues?
Answer
(C)
DNA from different tissues in the same organism should usually have the same base composition
43
What is the approximate width of the B-form DNA double helix in nanometers?
Answer
(B)
2
44
How many base pairs are typically found in a single complete turn of the B-form DNA molecule?
Answer
(C)
10
45
What is the distance, in nanometers, covered by one full turn of B-form DNA?
Answer
(D)
3.4 nm
46
If the thymine concentration in a DNA molecule is 30%, what is the predicted concentration of guanosine?
Answer
(B)
20%
47
If the guanosine content in a DNA molecule is 40%, what would be the percentage of adenine?
Answer
(A)
10%
48
What factor leads to a higher melting temperature in duplex DNA?
Answer
(C)
Cytosine + Guanine
49
What condition is often treated with the synthetic nucleotide analogue, 4-hydroxypyrazolopyrimidine?
Answer
(B)
Gout
50
Which synthetic nucleotide analogue is frequently used in cancer and viral infection treatment?
Answer
(A)
Arabinosyl cytosine