DNA Replication_Exam 3

Question 1

This links nucleotide bases together. The hydroxyl group on one base bind with phosphate on adjacent base

Answer 1

Phosphodiester bond

Question 2

Components of a DNA’s Structure

Answer 2

Antiparallel and noncovalent interactions

Question 3

2 strands in double helix run in opposite directions, double helix held together by non-covalent interactions

Answer 3

Antiparallel

Question 4

DNA structure with hydrogen bonds and hydrophobic interactions

Answer 4

noncovalent interactions

Question 5

Each daughter cell contains 1 parent strand + 1 new strand

Answer 5

Semiconservative

Question 6

starts at several points (origins) and its replication ‘bubble’ is formed

Answer 6

bidirectional with multiple origins

Question 7

Characteristics of Eukaryotic DNA replication

Answer 7

Semiconservative and bidirectional with multiple origins

Question 8

Primed by RNA is a characteristic for what?

Answer 8

Eukaryotic DNA replication

Question 9

DNA polymerases cannot cannot synthesize new DNA without short stretches of ___

Answer 9

RNA (primer)

Question 10

DNA ____ makes small stretches of RNA

Answer 10

primase

Question 11

DNA polymerases elongate DNA chain by addition of base pairs to ____ end

Answer 11

3’

Question 12

Sequence of base pairs added is dictated by base pair of ___ ____

Answer 12

coding strand

Question 13

Semidiscontinuous process: New DNA always synthesized in

Answer 13

5’ –> 3’ direction

Question 14

Semidiscontinuous process: Parental strand read from

Answer 14

3’ –>5’

Question 15

Semidiscontinuous process: Continuously synthesized from 5’ –> 3’ on

Answer 15

leading strand

Question 16

Semidiscontinuous process: ___ ____ is synthesized from 5’ –> 3’, but discontinuous = ___ ____

Answer 16

Lagging strand, okazaki fragments

Question 17

Proteins involved in DNA replication?

Answer 17

DNA Polymerases, DNA Helicases, DNA primases, Single-stranded DNA binding proteins, DNA ligase, toposiomerases and telomerase

Question 18

This protein adds nucleotides to 3’ end during replication of new DNA, and some are able to proofread & remove wrong nucleotides in 3’-5’ direction

Answer 18

DNA Polymerases

Question 19

This protein unwinds parental DNA double helix and requires ATP to form the replication fork

Answer 19

DNA Helicases

Question 20

This protein synthesizes short RNA primers for DNA synthesis

Answer 20

DNA primases

Question 21

This protein prevents premature binding & winding of DNA (aka. annealing)

Answer 21

single-stranded DNA binding proteins

Question 22

This protein joins nucleotide fragments by forming phosphodiester bonds and requires ATP

Answer 22

DNA Ligase

Question 23

This protein facilitates unwinding of double helix during replication & transcription to release torsional stress and functions ahead of replication fork

Answer 23

topoisomerases

Question 24

This protein adds TTAGGG repeats to the ends of chromosomes in stem cells, progenitor cells & cancer, giving them immortality

Answer 24

Telomerase

Question 25

1. Steps in DNA replication: ___ unwinds DNA forming replication fork

Answer 25

Helicase

Question 26

2. Steps in DNA replication: ____ prevent DNA from rewinding

Answer 26

Single-stranded DNA binding proteins

Question 27

3. Steps in DNA replication: ___ ads RNA to origin of DNA synthesis

Answer 27

DNA primases

Question 28

4. Steps in DNA replication: ____ adds nucleotides in 5'-3' direction (to 3' end of strand)

Answer 28

DNA Polymerase

Question 29

5. Steps in DNA replication: ____ is continuous

Answer 29

leading strand

Question 30

6. Steps in DNA replication: ___ is discontinuous forming okazaki fragments

Answer 30

lagging strand

Question 31

7. Steps in DNA replication: ___ are removed

Answer 31

RNA Primers

Question 32

8. Steps in DNA replication: ___ joins fragments formed

Answer 32

DNA Ligase

Question 33

This type of damage is internal, spontaneous & is due to errors in DNA replication

Answer 33

Endogenous damage

Question 34

This type of DNA damage is environmental, and ionizing radiation, polyaromatic hydrocarbons, nitrosamines, free radicals, and chemotherapy

Answer 34

Exogenous mutagens

Question 35

This type of DNA repair fixes mismatch repair in normal base pairing (AT, GC) and identifed by protiens

Answer 35

Mismatch repair

Question 36

This DNA repair corrects spontaneous depurination (loss of purines) or deamination (cytosine loses amine to form uracil)

Answer 36

Base excision repair

Question 37

This type of DNA repair removes mutations formed by UV light and environmental chemicals

Answer 37

Nucleotide excision repair

Question 38

This type of DNA repair uses info from unaffected chromosome to fix

Answer 38

Double-stranded DNA repair