flow of gen info

Question 1

Catalyze changes in supercoiled state of DNA.

Answer 1

Topoisomerases

Question 2

3 distinct phases of DNA replication

Answer 2

Initiation, elongation, and termination

Question 3

Termination is different at?

Answer 3

Telomeres of eukaryotic chromosomes

Question 4

Corrects error using highly evolved correction systems

Answer 4

DNA repair

Question 5

Proceeds at a rate ranging from 500-5000 nucleotides per minute at each replication fork

Answer 5

Eukaryotic replication

Question 6

Replication indeed begins at _____, but double helix then unwinds in ______, replicating DNA both ways away from ___.

Answer 6

Origin of replication, opposite directions, replication forks

Question 7

A replication where each strand of the double helix parent DNA serve as a template to make 2 new daughter or complementary strands, and who demonstrated it?

Answer 7

Semiconservative replication. Meselson and Stahl

Question 8

DNA synthesis is initiated at special regions called

Answer 8

Replication origins

Question 9

Individual units of replications and region of DNA served by one replication origin are called

Answer 9

Replicons

Question 10

A common type of replication that takes place in circular DNA (E.coli)

Answer 10

Theta replication

Question 11

Takes place in some viruses and in the F factor of E.coli

Answer 11

Rolling-circle replication

Question 12

Replication takes place simultaneously from thousands of origins

Answer 12

Linear eukaryotic replication

Question 13

What proteins unwinds parental double helix at replication forks?

Answer 13

Helicase

Question 14

Bind to and stabilizes single-stranded DNA until it can be used as a template

Answer 14

Single-stranded binding protein

Question 15

Corrects overwinding ahead of replication forks by breaking, swiveling, and rejoining dna strands

Answer 15

Topoisomerase

Question 16

A single DNA strand that, during DNA replication, is replicated in the 3’ – 5’ direction (same direction as the replication fork).

Answer 16

Leading strand

Question 17

DNA replication is a sequence of repeated condensation _______ reactions linking nucleotide monomers into a DNA polymer.

Answer 17

Dehydration synthesis

Question 18

Sequences at replication of origins that bind to initiation proteins tend to be rich in ______ and ______.

Answer 18

Adenine and Thymine bases

Question 19

It control the initiation of DNA replication by directing assembly of the replication machinery to specific sites on the DNA chromosomes.

Answer 19

Origin-binding protein

Question 20

3 types of replication origins

Answer 20

E.coli, yeast autonomously replicating sequence, and simian virus 40 origin.

Question 20

In this phase, DNA nucleotides are then added to the 3’‐ends of primers by a DNA polymerase (DNA pol).

Answer 20

Elongation

Question 20

Only one primer is required for DNA pol III to synthesize the _____.

Answer 20

Leading strand

Question 21

Is synthesized discontinuously, as a series of segments or fragments.

Answer 21

Lagging strand

Question 22

The segments of the lagging strand are called

Answer 22

Okazaki fragments

Question 23

What initiates the DNA synthesis in the cell?

Answer 23

RNA polynucleotide primer

Question 24

It catalyzes the addition of a nucleoside triphosphate to the 3’ end of a growing DNA strand, with the release of two phosphates.

Answer 24

DNA polymerase

Question 25

The enzyme that is responsible for the polymerization of nucleotides to nucleic acid (DNA) during the elongation phase of DNA REPLICATION

Answer 25

DNA polymerase

Question 26

The 1st DNA polymerase discovered and is distributive.

Answer 26

DNA Pol I

Question 26

Known as main DNA repair enzymes

Answer 26

Pol I and II

Question 27

Known as the main DNA replication enzyme and is highly “processive”

Answer 27

Pol III

Question 28

Is continuous synthesis by polymerase without dissociation from the template. (It can be observed in the leading template strand)

Answer 28

Processivity

Question 29

It will dissociate from the template after each nucleotide addition. (It can be observed in the lagging template strand).

Answer 29

DNA polymerase that is Distributive

Question 30

Seals gaps or nicks.

Answer 30

DNA ligase

Question 31

Linear chromosomes (ie. DNA molecules) have a unique problem replicating their ends or _____.

Answer 31

Telomeres

Question 31

What enzyme prevents progressive shortening of Lagging Strands during eukaryotic DNA Replication? An RNA‐directed DNA polymerase, containing RNA template

Answer 31

Telomerase

Question 32

The protein component of telomerase is a _____, an enzyme that can make DNA copies from RNA templates.

Answer 32

Reverse transcriptase

Question 32

The ends of the linear chromosomes and contains a catalytic part and a built‐in RNA template.

Answer 32

Telomeres

Question 33

Telomerase is typically active in ____ and adult stem cells. It is not active in adult somatic cells.

Answer 33

Germ cells, somatic cells

Question 33

This essentially means that telomere shortening is associated with _____

Answer 33

Aging

Question 33

Fidelity of DNA replication can be traced to three distinct activities:

Answer 33

1. accurate selection of nucleotides 2. immediate proofreading 3. postreplicative mismatch repair

Question 33

A failure to repair DNA produces a

Answer 33

Mutations

Question 34

Not by external factors but within natural cell processes during replication

Answer 34

Spontaneous

Question 34

The mechanism of DNA repair can be divided into 2 major classes

Answer 34

Direct reversal and excision repair

Question 35

2 general types of DNA damage

Answer 35

Induced and spontaneous

Question 35

Caused by external factors or substances

Answer 35

Induced

Question 36

Chemical reaction responsible for DNA damage

Answer 36

Direct reversal

Question 36

Removal of the damaged bases followed by their replacement with newly synthesized DNA

Answer 36

Excision repair

Question 36

This is another mechanism by the cell for dealing with mistakes that slip by proofreading during replication.

Answer 36

Mismatch repair

Question 37

3 types of excision repair

Answer 37

Base excision repair (BER) Nucleotide excision repair (NER) Mismatch repair (MMR)

Question 37

This pathway starts with a DNA glycosylase. Here, the enzyme uracil DNA glycosylase removes an accidentally deaminated cytosine in DNA.

Answer 37

Base excision repair (BER)