Nucleic Acids

Question 1

Types of nucleic acids

Answer 1

1. deoxyribonucleic acid (DNA)
2. ribonucleic acid (RNA)

Question 2

Nearly all is found within the cell nucleus

Answer 2

deoxyribonucleic acid (DNA)

Question 3

Its primary function is the storage and transfer of genetic information.

Answer 3

DNA

Question 4

is passed from existing cells to new cells during cell division.

Answer 4

DNA

Question 5

occurs in all parts of a cell.

Answer 5

ribonucleic acid (RNA)

Question 6

It functions primarily in synthesis of proteins, the molecules that carry out
essential cellular functions.

Answer 6

RNA

Question 7

Components of nucleic acids

Answer 7

1. five-carbon (pentose) sugar
2. phosphate
3. four heterocyclic amines called nitrogenous bases.

Question 8

Chemical Composition of Phosphate Group

Answer 8

PO43-

Question 9

Chemical Composition of Sugars

Answer 9

2’-Deoxyribose (in DNA) - C5H10O4
Ribose (in RNA) - C5H10O5

Question 10

Chemical Compositions in Bases

Answer 10

Purines (double ring)
Adenine (A) - C5H5N5
Guanine (G) - C5H5N5O

Pyrimidines (single ring)
Thymine (T) (in DNA) - C5H6N2O2
Cytosine (C) - C4H5N3O
Uracil (U) (in RNA) - C4H4N2O2

Question 11

is an unbranched polymer containing monomer units called nucleotides.

Answer 11

nucleic acid

Question 12

is a three-subunit molecule in which a pentose sugar is bonded to both a phosphate group and a nitrogen-containing heterocyclic base.

Answer 12

nucleotide

Question 13

are produced by the combination of a sugar, either ribose (in RNA) or 2′-deoxyribose (in DNA), with a purine or a pyrimidine base.

Answer 13

Nucleosides

Question 14

difference between the two sugars occurs at

Answer 14

carbon 2′

Question 15

difference between the two sugars DNA and RNA

Answer 15

The —OH group present in ribose becomes an —H atom in 2′-deoxyribose.

Question 16

The prefix deoxy- means

Answer 16

“without oxygen”

Question 17

“pure silver” code

Answer 17

Purine A and G

Question 18

6-membered ring made up of carbon and nitrogen atoms

Answer 18

Pyrimidines

Question 19

Uracil chemical name

Answer 19

2,4-dioxypyrimidine

Question 20

Thymine chemical name (2)

Answer 20

• 2,4-dioxy-5-methylpyrimidine
• 5-methyluracil

Question 21

Cytosine chemical name

Answer 21

2-oxy-4-aminopyrimidine

Question 22

6 membered ring fused to a 5 membered ring

Answer 22

Purines

Question 23

Adenine chemical name

Answer 23

6-aminopurine

Question 24

Guanine chemical name

Answer 24

2-amino-6-oxypurine

Question 25

nitrogen-containing heterocyclic bases

Answer 25

1. Purines 2. Pyrimidines

Question 26

example of derivative of purine

Answer 26

caffeine

Question 27

example of derivative of pyrimidine

Answer 27

Thiamine (Vit B)

Question 28

derived from phosphoric acid (H3PO4

Answer 28

phosphate

Question 29

the phosphoric acid loses two of its hydrogen atoms to give a hydrogen phosphate ion (HPO4^2−) under what conditions?

Answer 29

Under cellular pH conditions

Question 30

Structural building block of ribonucleotide adenosine triphosphate, highest to lowest

Answer 30

1. Adenosine triphosphate 2. Adenosine diphosphate 3. Adenosine monophosphate 4. Adenosine

Question 31

suffix for purine bases

Answer 31

-osine ex. adenosine, guanosine

Question 32

suffix for pyrimidine bases

Answer 32

-idine ex. cytidine, thymidine, uridine

Question 33

Nucleoside formation

Answer 33

sugar + base

Question 34

Nucleotide formation

Answer 34

nucleoside + phosphate

Question 35

Important characteristics of the process of nucleoside formation. State the first characteristic.

Answer 35

The base is always attached to C1′ of the sugar, which is always in a β-configuration. For purine bases, attachment is through N9; for pyrimidine bases, N1 is involved. The bond connecting the sugar and base is a β-N-glycosidic linkage

Question 36

Important characteristics of the process of nucleoside formation. State the second characteristic.

Answer 36

A molecule of water is formed as the two molecules bond together; a condensation reaction occurs.

Question 37

The prefix ________ is used to indicate that the sugar present is deoxyribose

Answer 37

deoxy-

Question 38

are nucleosides that have a phosphate group bonded to the pentose sugar present.

Answer 38

Nucleotides

Question 39

Important characteristics of the nucleotide formation process: first process

Answer 39

1. The phosphate group is attached to the sugar at the C5′ position through a phosphoester linkage.

Question 40

Important characteristics of the nucleotide formation process: second characteristic

Answer 40

2. As with nucleoside formation, a molecule of water is produced in nucleotide formation. Thus, overall, two molecules of water are produced in combining a sugar, base, and phosphate into a nucleotide.

Question 41

Nucleotide Primary structure

Answer 41

Base l Phosphate------Sugar

Question 42

Nucleic Acid Backbone

Answer 42

Phosphate l Sugar

Question 43

DNA Backbone

Answer 43

Phosphate l Deoxyribose

Question 44

RNA Backbone

Answer 44

Phosphate l Ribose

Question 45

Because the sugar–phosphate backbone of a given nucleic acid does not vary, the primary structure of the nucleic acid depends only on the sequence of bases present.

Answer 45

5′ T–G–C–A 3′

Question 46

Important points about the nucleic acid primary structure: 1.

Answer 46

Each nonterminal phosphate group of the sugarphosphate backbone is bonded to two sugar molecules through a 3′,5′- phosphodiester linkage.

Question 47

Important points about the nucleic acid primary structure: 2.

Answer 47

A nucleotide chain has directionality. (5' end to the 3' end or vice versa)

Question 48

Important points about the nucleic acid primary structure: 3.

Answer 48

Each nonterminal phosphate group in the backbone of a nucleic acid carries a 1– charge. The remaining –OH group is free to exhibit acidic behavior—that is, to produce an H+ ion.

Question 49

Three parallels between protein and nucleic acid primary structure: 1.

Answer 49

1. DNAs, RNAs, and proteins all have backbones that do not vary in structure.

Question 50

Three parallels between protein and nucleic acid primary structure: 2.

Answer 50

The sequence of attachments to the backbones (nitrogen bases in nucleic acids and amino acid R groups in proteins) distinguishes one DNA from another, one RNA from another, and one protein from another.

Question 51

Three parallels between protein and nucleic acid primary structure: 3,

Answer 51

Both nucleic acid polymer chains and protein polymer chains have directionality; for nucleic acids, there is a 5′ end and a 3′ end, and for proteins, there is an N-terminal end and a Cterminal end.