Module 32

Question 1

What is NDA made up of

Answer 1

Nucleotides

Question 2

3 Key features of DNA

Answer 2

1. Store genetic info
2. Direct synthesis of other macros
3. Transmits genetic information from one DNA molecule to another

Question 3

DNA Replicatoion

Answer 3

a process where DNA is able to specify exact copies of itself

Question 4

Purine Bases

Answer 4

A and G

Question 5

Pyrimidine Bases

Answer 5

T and C

Question 6

Antiparallel

Answer 6

How the DNA strands run in relation of each other

5’->3’
3’<-5’

Question 7

Replication Fork

Answer 7

The site where parental DNA strands unwind and separate

Question 8

Semiconservative replication

Answer 8

Each DNA consists of one parental strand and one newly synthesized daughter strand

Question 9

Conservative Replication

Answer 9

Proposes that DNA molecules remain intact and daughter cells are completely new

Question 10

Who tested the way in which DNA replicates

Answer 10

Meselson and Stahl

Question 11

How does base pairing ensure that parental strand and daughter strand have exactly the same DNA

Answer 11

Complimentary base pairing of the DNA molecule and their antiparallel structure.

Question 12

Mechanisms by which DNA replicates

Answer 12

Opening of the double helix
Separation and unwinding of the DNA strands at the replication fork

Question 13

Where does DNA replication begin at

Answer 13

the Replication Fork

Question 14

Helicase

Answer 14

The enzyme that separates the parental strands
Breaks hydrogen bonds between nucleotides

Question 15

Single-stranded binding protiens

Answer 15

Bind to separate regions of the DNA molecule to prevent them from coming back together

Question 16

Topoisomerase

Answer 16

Release the stress of the unwinding DNA molecule before it gets to the replication fork
Works upstream from the replication fork

Question 17

What doe the family of topoisomerase enzymes do

Answer 17

Winds, unwinds, or helps relieve stress that occurs during replication and transcription

Question 18

DNA Polymerase

Answer 18

Highly conserved, since they carry out essential functions

Replicates DNA

Question 19

Properties of DNA polymerase

Answer 19

1. It can only attach one nucleotide to another at one time
   - It can only elongate one end of the DNA
2. It can only add nucleotides to the 3’ end of the strand

Question 20

Primer

Answer 20

A starter for DNA synthesis
A short stretch of RNA

Question 21

What must each new strand of DNA begin with

Answer 21

Primer
A short stretch of RNA

Question 22

RNA primase

Answer 22

The enzyme that makes DNA primer

Question 23

Where is the Hydroxyl group on RNA primers

Answer 23

On the 3’ carbon
OH-

Question 24

Where is the phosphate on RNA primers

Answer 24

On the 5’ carbon

Question 25

When does DNA synthesis occur

Answer 25

When the 3’ OH- group attacks the phosphate group of the incoming nucleotide (It’s trisphosphate)

5’–>3’ direction

Question 26

Polymerization

Answer 26

DNA synthesis
When the 3’ OH- group attacks the phosphate group of the incoming nucleotide (It’s trisphosphate)

Question 27

In what direction does polarization occur

Answer 27

5’–>3’ direction

Question 28

Where does the energy required for the polymerization reaction come from

Answer 28

When the OH- group of RNA attacks the phosphate group of the nucleotide, the two other phosphates are released in the process

The high-energy PHOSPHATE BOND IS BROKEN

Question 29

Leading Strand

Answer 29

The daughter strand that can be synthesized in one continuous polymer

Has its 3’ end pointing towards the replication site

Question 30

Lagging Strand

Answer 30

Has multiple pieces that reach each other

3’ end points way from the replication site

Question 31

Okazaki Fragments

Answer 31

Result of lagging strand / 3’ being away from the replication fork

Short, discontinuous. pieces of DNA

Question 32

DNA replication process

Answer 32

DNA is unwinded at the Replication Fork
RNA Primer is laid
Synthesis of new strand at 3’

Question 33

Reason for Okazaki Fragments

Answer 33

Without them, the DNA would have to unzip all the way before synthesis, posing the risk that the DNA parental strand folds in on itself

Question 34

What do leading and lagging strands share

Answer 34

They are complementary to each other and their parental strand

Question 35

What do all DNA strands have at their 5’ end

Answer 35

RNA primers

Question 36

When is the RNA primer removed

Answer 36

When a growing fragment comes into contact with the primer of the earlier fragment

Question 37

What removes a RNA primer

Answer 37

A different DNA polymerase
It also extends the growing fragment to fill in the space of the removal

Question 38

DNA ligase

Answer 38

Joins all the adjacent gradients of the new DNA

Question 39

What is the reason behind leading and lagging strands

Answer 39

DNA’s anti-parallel nature

Question 40

Why is it important DNA replication occurs accurately

Answer 40

Mutations can occur

Question 41

Proofreading

Answer 41

Most DNA polymerases are able to do this
DNA polymerase can immediately correct its own errors during DNA synthesis

Detects mispairing between the template and most recently added nucleotide; removes it; and corrects it

Question 42

What holds new nucleotides in place

Answer 42

Hydrogen bonds between new pairs

Question 43

Importance of mutations

Answer 43

They allow populations of organisms to change through time and adapt to their environment