semi-conservative replication

Question 1

stage 1

Answer 1

DNA helicase breaks the hydrogen bonds between the complimentary bases of two DNA polymers, which causes the double helix to unwind and the two strands separate

Question 2

stage 2

Answer 2

both strands act as a template for DNA replication

Question 3

stage 3

Answer 3

free-floating activated DNA nucleotides align opposite their complimentary base on the template strand of DNA. Hydrogen bonds form between the base pairs

Question 4

stage 4

Answer 4

DNA polymerase joins adjacent DNA nucleotides together, forming a phosphodiester bond between these nucleotides to create a new polymer chain of DNA

Question 5

define semi-conservative replication

Answer 5

Two new identical DNA molecules are formed each containing one original template strand and one newly synthesised strand of DNA.

Question 6

what is the role of DNA helicase?

Answer 6

travels along DNA backbone, catalysing reactions that break hydrogen bonds between complimentary base pairs, separating two strands of DNA

Question 7

what is the role of DNA polymerase?

Answer 7

catalyses the formation of phosphodiester bonds between free nucleotides and template strands

Question 8

when does DNA replication occur

Answer 8

this occurs during the interphase of mitosis and meiosis

Question 9

why is DNA replicated before cell division?

Answer 9

so that each daughter cell can inherit the full set of DNA

Question 10

what are the 4 adaptations of DNA?

Answer 10

• stable: 2 strands, specific base pairs, many H bonds, helix shape, reduces risk of molecular damage
• strands separate: can self replicate
• base pairings: prevents corruption from chemical or physical forces
• large molecule: carry lots of info