Chapter 4 nucleic acids and an RNA world

Question 1

Chemical evolution

Answer 1

Lead to production of molecule that could sell replicate

Question 2

DNA

Answer 2

Stores genetic information and is replicated using proteins

Question 3

RNA world hypothesis

Answer 3

Proposes time in evolution where RNA both store genetic information and catalyzed its own replication

Question 4

Nucleic acid

Answer 4

Polymer of nucleotide monomers

Question 5

Three components of a nucleotide:

Answer 5

Phosphate group, five carbon sugar, nitrogenous base

Question 6

Phosphate group and nitrogenous base are:

Answer 6

Bonded to sugar molecule

Question 7

Ribonucleotides

Answer 7

Are monomers of RNA

Question 8

Deoxyribonucleotide’s are

Answer 8

Monomers of DNA

Question 9

Sugar is

Answer 9

Deoxyribose, deoxy equals lacking oxygen

Question 10

Two groups of nitrogenous bases:

Answer 10

Purines, pyrimidines

Question 11

Purines

Answer 11

Contain nine atoms in their two rings, adenine and guanine

Question 12

Pyrimidines

Answer 12

Contains six atoms in their one ring, Cytosine, Uracil (found only in RNA), and Thymine (found only in DNA)
( CUT of Py)

Question 13

How do you nucleotides polymerize to form nucleic acids?

Answer 13

Nucleic acids polymerize via condensation reactions

Question 14

Phosphodiester linkage bond occurs between:

Answer 14

Phosphate group on five prime carbon of one nucleotide and OH group on the three prime carbon of another

Question 15

Phosphodiester linkage

Answer 15

Join Ribo nucleotides together

Question 16

Nucleic acid polymerization

Answer 16

Can take place in cells by use of enzymes

Question 17

Potential energy is raised by:

Answer 17

Adding two additional phosphate groups

Question 18

Nucleic acid polymerization creates nucleoside triphosphates “_________”

Answer 18

Activated nucleotides

Question 19

Energy is released when activated nucleotides polymerize

Answer 19

Makes reaction spontaneous

Question 20

What is the nature of DNAs secondary structure?

Answer 20

 Early data provided clues to DNA secondary structure: DNA polymerase through formation of phosphate linkages
Molecule has sugar phosphate backbone
Number of purines equaled number of pyrimidines: Equal number of Ts and As; equal number of Cs and Gs

Question 21

X-ray crystallography

Answer 21

Used to measure distances between atoms in DNA, predicted helical structure

Question 22

James Watson and Francis Crick determined

Answer 22

Two strands are held together by hydrogen bonds between pyrimidines and purines

Question 23

Complementary base pairing (Watson-Crick pairing) occurs:

Answer 23

Between A and T, C and G

Question 24

DNA strands are anti-parallel

Answer 24

Antiparallel strands predicted to twist together to form double helix

Question 25

DNA has two different sized grooves:

Answer 25

Major groove and minor groove

Question 26

Two forms of DNA tertiary structure:

Answer 26

DNA is wound to tightly or loosely, twists to form super coils
DNA wraps around DNA binding proteins called histones

Question 27

 Watson and crick’s model revealed DNA as the

Answer 27

Biological Reservoir of information

Question 28

Biological reservoir of information

Answer 28

Stores information required for organisms growth and reproduction, information consists of sequences of nucleotides in nucleic acid

Question 29

DNA replication has three steps: