DNA REPLICATION AND STRUCTURE

Question 1

What is DNA made out of?

Answer 1

Nucleotides

Question 2

What is a nucleotide?

Answer 2

A nucleotide is repeating chemicals units in DNA

Question 3

What is a nucleotide made out of?

Answer 3

Deoxyribose sugar, phosphate and base

Question 4

What is the sugar-phosphate backbone?

Answer 4

The sugar phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule.

Question 5

What are the 4 bases in DNA

Answer 5

Adenine, Thymine, guanine, cytosine

Question 6

What 4 bases pair together?

Answer 6

Adenine, Thymine, Guanine,cytosine

Question 7

How are the bases held together?

Answer 7

By weak hydrogen bonds.

Question 8

What is the term to describe the structure of DNA?

Answer 8

Antiparallel.

Question 9

What do you need for DNA replication?

Answer 9

Primers
Original DNA template
Free DNA nucleotides
DNA polymerase
Ligase
ATP

Question 10

When is DNA REPLICATED

Answer 10

It is replicated prior to cell division.

Question 11

What is DNA replicated by?

Answer 11

DNA is replicated by DNA POLYMERASE.

Question 12

What does DNA polymerase need to start replication?

Answer 12

Primers

Question 13

What are primers?

Answer 13

Primers are short strands of nucleotides which bind to the 3’ end of the template allowing polymerase to add DNA nucleotides

Question 14

Explain the steps of DNA replication

Answer 14

DNA unwinds and unzips by breaking hydrogen bonds between the bases
Then primers attach to the 3’ end of the DNA strands
DNA polymerase synthesises the new DNA strands by adding complementary bases in a 5’ to 3’ direction.
Fragments are glued together with ligase and the 2 new DNA molecules wind back together

Question 15

How does the leading strand replicate?

Answer 15

Continuously.

Question 16

How does the lagging strand replicate?

Answer 16

In fragments

Question 17

What is PCR?

Answer 17

PCR is DNA replication in a lab

Question 18

What does PCR stand for?

Answer 18

It stands for polymerase chain reaction.

Question 19

What does PCR do?

Answer 19

It amplifies DNA using complementary primers for specific target sequences

Question 20

Explain the process of PCR

Answer 20

DNA is heated to 95 degrees Celsius to break the hydrogen bonds and separate the DNA strands
DNA is cooled to 55 degrees Celsius to allow primers to bing primers bind to the 3’ end of each strand.
DNA is heated to 75 degrees Celsius
Heat tolerant DNA polymerase is added and the DNA polymerase synthesises the new strands in a 5’ to 3’ direction
DNA molecules then recoil