DNA and Protein Synthesis

Question 1

What are the 4 complementary bases?

Answer 1

Guanine - Cytosine

Thymine - Adenine

Question 2

What holds complementary base pairs together?

Answer 2

Weak hydrogen bonds

Question 3

How many hydrogen bonds hold Guanine and Cytosine together?

Answer 3

3

Question 4

How many hydrogen bonds hold Thymine and Adenine together?

Answer 4

2

Question 5

What holds nucleotides together?

Answer 5

Strong chemical bonds

Question 6

Describe the structure of DNA

Answer 6

DNA is a double stranded helix with a sugar-phosphate backbone. The strands run anti-parallel to each other and is arranged so that it tightly coils into a chromosome

Question 7

Explain stage 1 of DNA replication

Answer 7

Double helix unwinds using the enzyme helicase

Question 8

Explain stage 2 of DNA replication

Answer 8

Weak hydrogen bonds between complementary base pairs break and cause the two DNA strands to unzip

Question 9

Explain stage 3 of DNA replication

Answer 9

Free DNA nucleotides from the nucleoplasm enter join their complimentary base pair on the open strand using DNA polymerase

Question 10

Explain stage 4 of DNA replication

Answer 10

Weak hydrogen bonds begin to reform between base pairs

Question 11

Explain stage 5 of DNA replication

Answer 11

Strong chemical bonds form between nucleotides controlled by the enzyme polymerase

Question 12

Explain stage 6 of DNA replication

Answer 12

The 2 strands begin to form back into a double helix. 2 newly formed daughter strands are created that are identical to the parent/original strand.

Question 13

What is DNA Polymerase?

Answer 13

DNA Polymerase controls the sugar-phosphate bonding between nucleotides on the new DNA strand.

Question 14

What type of replication is DNA replication known as?

Answer 14

Semi-conservative replication as one strand from the original DNA molecule is used in the twodaughter molecules

Question 15

What is a DNA primer?

Answer 15

A DNA primer initiates DNA replication and is always on the third carbon of the original strand

Question 16

What is the leading strand?

Answer 16

The leading strand is the strand of DNA that during DNA replication builds continuously in the correct direction towards the unzipping point.

Question 17

What is the lagging strand?

Answer 17

The lagging strand is the strand that during DNA replication builds discontinuously in the wrong direction away from the unzipping point.

Question 18

What is the lagging strand split up into?

Answer 18

Okazaki fragments

Question 19

What enzyme is used to join the okazaki fragments?

Answer 19

Ligase

Question 20

What is transcription?

Answer 20

The synthesis of mRNA from a section of DNA

Question 21

What is stage 1 of transcription?

Answer 21

The DNA double helix unwinds

Question 22

What is stage 2 of transcription?

Answer 22

Weak hydrogen bonds break between the bases causing the DNA molecule to split into two different strands

Question 23

What is stage 3 of transcription?

Answer 23

Free mRNA nucleotides find their complimentary pair in the DNA strand

Question 24

What is stage 4 of transcription?

Answer 24

Weak hydrogen bonds are reformed between the new bases

Question 25

What is stage 5 of transcription?

Answer 25

Strong chemical bonds are formed between the new mRNA nucleotides opposite to DNA. This allows a new strand to be formed

Question 26

What is stage 6 of transcription?

Answer 26

Bonds between the DNA and mRNA bases break allowing the mRNA to leave the DNA template

Question 27

What is stage 7 of transcription?

Answer 27

The mRNA is now ready to exit the nucleus through a pore and enter the cytoplasm

Question 28

What is stage 8 of transcription?

Answer 28

The weak hydrogen bonds between the DNA bases reform and twist into a double helix