DNA replication

Question 1

How is DNA replicated in humans

Answer 1

Semi-conservatively

Question 2

4 requirements of semi conservative replication

Answer 2

1) four types of nucleotides (A,T,G,C)
2)both strands of DNA molecule acting as a template for the attachment of nucleotides.
3)the enzymes DNA polymerase and DNA helicase
4)source of chemical energy to drive the process

Question 3

Step 1 of DNA rep

Answer 3

DNA helicase breaks the hydrogen bonds between bases. This allows the double helix to unwind. The two strands act as template

Question 4

Step 2 of DNA rep

Answer 4

Free floating DNA nucletotides attracted to exposed bases via complementary base pairing. they then form hydrogen bonds

Question 5

Step 3 of DNA rep

Answer 5

DNA polymerase joins adjacent nucleotides on new strands by condensation recation,forming phosphodiester bonds

Question 6

Why is the replication called semi conservative

Answer 6

Each new strand formed contains one original and one new strand

Question 7

Importance of Complementary shape

Answer 7

DNA nucleotides join by specific complementary base pairing—–> allows for accurate replication of DNA so identical copies can be made. Knock on effect on mitosis (S-phase)

Also enzymes DNA polymerase and helicase need to be complementary—–> allows DNA to unwound and joins adjacent nucleotides together.