MIDTERM 02 - Replication

Question 1

3 central dogmas of molecular biology (DTT)

Answer 1

DNA replication, Transcription, Translation

Question 2

The process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules (Central dogmas of molecular biology)

Answer 2

DNA replication

Question 3

The process of making an RNA copy of a gene’s DNA sequence (Central dogmas of molecular biology)

Answer 3

Transcription

Question 4

The process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids during protein synthesis (Central dogmas of molecular biology)

Answer 4

Translation

Question 5

Is a requirement of cell division; the process wherein DNA molecules are duplicated before cell division and passed on to each daughter cell

Answer 5

DNA replication

Question 6

DNA replication happens inside the nucleus during the __________ of the cell cycle

Answer 6

S-phase

Question 7

3 main steps involved in DNA replication (IET)

Answer 7

Initiation, Elongation, Termination

Question 8

Enzyme that unzips the double-helix (Initiation phase)

Answer 8

Helicase

Question 9

Proteins that bind temporarily to each DNA strand to keep them separated (Initiation phase)

Answer 9

Single-strand binding proteins (SSBP)

Question 10

Enzyme that adjusts how tight the strands are as the replication bubble grows bigger (Initiation phase)

Answer 10

Topoisomerase

Question 11

Enzymes that synthesizes the RNA primers using the parental DNA as a template to start elongation (Elongation phase)

Answer 11

Primase

Question 12

Enzyme that synthesizes new DNA nucleotides in a 5’ to 3’ direction (Elongation phase)

Answer 12

DNA polymerase III

Question 13

Is the complementary strand that is continuously synthesized in the 5’ to 3’ direction (Elongation phase)

Answer 13

Leading strand

Question 14

Is the complementary stand that is discontinuously synthesized via Okazaki fragments (Elongation phase)

Answer 14

Lagging strand

Question 15

Enzyme that proofreads the DNA molecule and removes the primers in a 3’ to 5’ direction (Termination phase)

Answer 15

DNA polymerase I

Question 16

Enzyme that seals the nicks or breaks left by the DNA polymerase I (Termination phase)

Answer 16

Ligase

Question 17

Phase of DNA replication that involves DNA unwinding

Answer 17

Initiation

Question 18

Phase of DNA replication that involves synthesis of complementary strand

Answer 18

Elongation

Question 19

Phase of DNA replication which stops the synthesis and involves ligation of the discontinuous strand

Answer 19

Termination

Question 20

Means that only one strand is synthesized from each daughter DNA distributed to cell offsprings

Answer 20

Semi-conservative

Question 21

Means that DNA is synthesized in both directions

Answer 21

Bidirectional

Question 22

Means that DNA polymerase can only add nucleotides at the 3’ end of the growing DNA making the direction of synthesis from 5’ to 3’

Answer 22

5’ to 3’ Direction

Question 23

Means that synthesis in the leading strand is continuous while in the lagging strand it is discontinuous

Answer 23

Semi-discontinuous

Question 24

The initiation phase of DNA replication happens in the __________

Answer 24

Origin of replication

Question 25

Enzymes that unwind the DNA helix (Initiation phase)

Answer 25

Helicase

Question 26

Enzymes that assist in the DNA unwinding (Initiation phase)

Answer 26

Topoisomerase

Question 27

Proteins that bind to the separated strand to stabilize the DNA (Initiation phase)

Answer 27

Single stranded binding proteins (SSBP)

Question 28

Enzyme that attaches the appropriate nucleotide from a 3’ to 5’ direction (Elongation phase)

Answer 28

DNA polymerase III

Question 29

Elongation of the leading strand is __________

Answer 29

Continuous

Question 30

Elongation in the lagging strand is __________

Answer 30

Discontinuous

Question 31

In the elongation phase of DNA replication, the lagging strand forms __________, which is from the discontinuous synthesis of the lagging strand

Answer 31

Okazaki fragments

Question 32

DNA replication is rapid, about __________ nucleotides per second

Answer 32

10^3 (10,000) nucleotides per second

Question 33

Errors in the DNA replication that occur spontaneously (only once in every 10^9 or 10 billion to 10^10 or 100 billion base pairs)

Answer 33

Mutation

Question 34

Mutations occur spontaneously, only once in every __________ to __________ base pairs

Answer 34

10^9 (10 billion)-10^10 (100 billion) base pairs

Question 35

Activity that removes mispaired nucleotides from the 3’ end of the growing DNA

Answer 35

3’ → 5’ Exonuclease activity

Question 36

Enzymes that removes and connects the nicks left by the discontinuous synthesis of DNA (Proofreading phase)

Answer 36

Ligase

Question 37

Are proteins that recognize a termination sequence of the DNA and block the progress of the replication form, hence terminating the replication (Termination phase)

Answer 37

Tus proteins