Chapter 8 Biochemistry

Question 1

What are the two constituents of nucleic acids?

Answer 1

DNA (Deoxyribonucleic Acid) and RNA (Ribonucleic Acid)

Question 2

What are the three basic components of nucleotides?

Answer 2

A nitrogenous base (pyrimidine or purine), a pentose, 1 or more phosphates.

Question 3

What is a Nucleoside?

Answer 3

A nucleic acid without a phosphate group.

Question 4

Why are the carbons on the sugar molecule in a nucleotide named with prime (‘) numbers?

Answer 4

It is the second cyclic structure in the nucleotide.

Question 5

LQ: What other name can be given to a nucleotide?
A) Glycosylated Nucleoside
B) Purinated Pentose
C) Deoxyribonucleotide
D) Nucleoside Phosphate

Answer 5

D) Nucleoside Phosphate

Question 6

Where is the N-β-Glycosyl Bond present in a nucleotide? What type of reaction forms this bond?

Answer 6

Covalently joins the 1’ carbon of the pentose to the base (at N-1 of pyrimidines and N-9 of purines). It is a condensation reaction (removal of one water molecule).

Question 7

What is connected by an ester bond in a nucleotide?

Answer 7

Phosphate group to the 5’ carbon of pentose.

Question 8

What are the two major purine bases?

Answer 8

Adenine and Guanine

Question 9

What are the three major pyrimidine bases?

Answer 9

Cytosine, Thymine, and Uracil

Question 10

What is the prefix on bases present in DNA vs. RNA?

Answer 10

Deoxy-

Question 11

What is the suffix of a base present on a nucleoside vs. nucleotide?

Answer 11

-osine vs. -ylate (Ex. Adenosine vs. Adenylate)

Question 12

What is the pentose present in DNA vs. RNA?

Answer 12

DNA: 2’-deoxy-D-ribose
RNA: D-ribose

Question 13

What is the structural difference between the pentoses present in DNA vs. RNA?

Answer 13

Ribose (RNA) contains a -OH group off 2’ vs. Deoxyribose (DNA) contains a -H off 2’

Question 14

What form are ribose and deoxyribose present in?

Answer 14

β-Furanose Form (Closed Five-Membered Ring)

Question 15

What is the name for the structural units of DNA and their three alternative names.

Answer 15

Deoxyribonucleotides.
Alternative Names: Deoxyyribonucleoside 5’-monophosphates, deoxynucleotides, and deoxynucleoside triphosphates.

Question 16

What is the key difference between the symbols/abbreviations of DNA vs. RNA nucleotides?

Answer 16

DNA contains a “d” in front (Ex. dAMP vs. AMP)

Question 17

LQ: What name is given to the nucleotide found in DNA and not in RNA?
A) Uridylate
B) Thymidine
C) Uracil
D) Deoxythymidylate

Answer 17

D) Deoxythymidylate

Question 18

What is the key structural difference between the minor vs. major bases for DNA?

Answer 18

Minor bases contain an additional methyl group.

Question 19

T/F: Nucleotides can have phosphate groups occurring at different positions other than 5’.

Answer 19

True