Deck 24: Biomolecules: Nucleic Acids and Their Metabolism

Question 1

Which of the following is uridine?

A)1
B)2
C)3
D)4

Answer 1

2

Question 2

The bond between the nitrogenous base and the sugar in a nucleoside is a glycosidic bond.Which type of reagent should cleave this bond?

A)acid
B)base
C)acid or base
D)neither acid nor base
E)It depends on which nitrogenous base and which sugar are present.

Answer 2

acid

Question 3

Rank DNA,mRNA,and tRNA from largest to smallest.

A)DNA > mRNA > tRNA
B)DNA > tRNA > mRNA
C)mRNA > tRNA > DNA
D)mRNA > DNA > tRNA
E)tRNA > mRNA > DNA

Answer 3

DNA > mRNA > tRNA

Question 4

How many hydrogen bonds are present in a G-C base pair and an A-T base pair,respectively?

A)1,2
B)2,2
C)2,3
D)3,2
E)3,3

Question 5

In some instances,base pairs other than the familiar G-C and A-T matches can form.For these alternate pairs to form,one of the two bases must tautomerize.Based on this information,draw a C-A pair and determine the number of hydrogen bonds that would stabilize the pair.

Question 6

Answer the following questions.
a) If the following segment of mRNA
(5') CUU-AGC-UGG-CCC (3')
was changed to
(5') CUU-AGC-UGG-CCU (3')
how would the synthesized protein change?
b) If the following segment of mRNA
(5') CUU-AGC-UGG-CCC (3')
was changed to
(5') CUU-AGC-UGA-CCU (3')
how would the synthesized protein change?

Question 7

The phosphodiester linkages in DNA and in RNA are,respectively:

A)2' to 3',3' to 2'
B)2' to 5',5' to 2'
C)3' to 5',5' to 3'
D)3' to 5',3' to 5'
E)5' to 5',3' to 3'

Question 8

Which of the following characterizes the polymerase chain reaction (PCR)?

A)produces multiple copies of DNA segments
B)requires small amount of the source DNA
C)the key to the process is a thermally stable enzyme
D)involves temperature cycling
E)all of these

Question 9

Which reagent is used to accelerate coupling reactions in both laboratory peptide synthesis and laboratory DNA synthesis?

A)catalytic H⁺
B)dicyclohexylcarbodiimide (DCC)
C)ethyl chloroformate
D)NaOH
E)PhS^- NH₄⁺

Question 10

Which is true?

A)Both DNA and RNA are completely double-stranded.
B)Both DNA and RNA are completely single-stranded.
C)Both DNA and RNA contain ribose.
D)Both DNA and RNA contain uracil.
E)Both DNA and RNA contain phosphate.

Question 11

Describe,in general terms,the steps involved in the automated synthesis of the DNA sequence GCT.

Question 12

Which of the following is 2-deoxy-D-ribose?

A)1
B)2
C)3
D)4

Question 13

A double-stranded DNA molecule that contains 22%,on a mole basis,T must also contain

A)11% G
B)22% G
C)28% G
D)56% G
E)78% G

Question 14

What amino acid sequence is coded by the following segment of DNA?
(5')TTA-GCC-GTA-CTA-AAA (3')

Question 15

DNA can best be described as

A)two backbones of alternating deoxyribose and nitrogenous base on the exterior,with phosphates on the interior
B)two backbones of alternating deoxyribose and nitrogenous base on the interior,with phosphates on the exterior
C)two backbones of alternating deoxyribose and phosphate on the exterior,with nitrogenous bases on the interior
D)two backbones of alternating deoxyribose and phosphate on the interior,with nitrogenous bases on the exterior
E)two backbones of alternating nitrogenous base and phosphate on the exterior,with deoxyriboses on the interior

Question 16

Which of the following is deoxyadenosine?

A)1
B)2
C)3
D)4

Question 17

What is the anticodon sequence in tRNA that corresponds the following segment of mRNA?
(5')CUU-AGC-UGG-CCC(3')

Question 18

What sequence of bases on the second strand of DNA is complementary to the following?
(5')GCATTA (3')

Question 19

Base pairs in DNA are

A)parallel to each other and parallel to the long axis of the DNA molecule
B)parallel to each other and perpendicular to the long axis of the DNA molecule
C)parallel to each other,with random orientations to the long axis of the DNA molecule
D)perpendicular to each other,with every other base pair parallel to the long axis of the DNA molecule
E)perpendicular to each other,with random orientations to the long axis of the DNA molecule

Question 20

What mRNA sequence is complementary to the following DNA base sequence?
(5')TAAGGCGATA (3')

Question 21

Which of the following is a definition of messenger RNA (mRNA)?

A)RNA found in the ribosome,the site in cells where synthesis of proteins takes place
B)RNA which carries a specific amino acid to the site of protein synthesis
C)RNA which has coded genetic information
D)RNA which signals cell death

Question 22

Which of the following represents the general sequence of events in the catabolism of nucleic acids?

A)hydrolysis,dephosphorylation,cleavage of the sugar
B)cleavage of the sugar,dephosphorylation,hydrolysis
C)dephosphorylation,hydrolysis,cleavage of the sugar
D)hydrolysis,cleavage of the sugar,dephosphorylation
E)dephosphorylation,cleavage of the sugar,hydrolysis

Question 23

What sequence is fully complementary to the following sequence?
(5')ATCTAGTCA (3')

A)(5')TAGATCAGT (3')
B)(5')TGACTAGAT (3')
C)(5')ATCTAGTCA (3')
D)(5')ACTGATCTA (3')