2.3.2: How DNA Replicates

Question 1

what type of replication is used in DNA?

Answer 1

semi-conservative replication

Question 2

what is the first step of DNA replication?

Answer 2

the double helix is untwisted by DNA gyrase and unzipped by DNA helicase breaking hydrogen bonds

Question 3

what is the second step to DNA replication?

Answer 3

free nucleotides in the cytoplasm are bonded to exposed bases following complementary base pairing

Question 4

what is the third step to DNA replication?

Answer 4

the enzyme DNA polymerase catalases the addition of new bases in 5’ to 3’ direction, to the single strands of DNA

Question 5

what is a leading and lagging strand?

Answer 5

the leading strand is continuously synthesised, the lagging strand is in fragments which are later joined by ligase enzymes

Question 6

what is the purpose of of the hydrolysis of the activated nucleotides?

Answer 6

this releases the extra phosphate groups and supplies energy to make phosphodiester bonds