A1 - DNA replication

Question 1

Explain semi-conservative process of DNA replication

Answer 1

-DNA helices breaks H bonds between base pairs, causing double helix structure to unwind
-free nucleotides bind to complementary bases on the exposed polynucleotide
-DNA polymerase builds up the polynucleotide by forming phosphodiester bonds (condensation reaction)
-2 new polynucleotide chains are formed. Each strand has half the original genetic material

Question 3

importance of DNA replication

Answer 3

-phosphodiester bonds in DNA are biologically important as they provide stability to molecule and protect the base sequence which is needed to code for a specific a.a sequence in protein synthesis
-H bonds can easily be broken down by DNA helicase > exposes bases in a template strand > complementary base pairings allows complementary bases to align with correct nucleotides and form h bonds > if h bonds were not present between bases then DNA could not replicate semi-conseveterarly as free nucleotides could not line up in correct sequence > could loead to inccorect sequence of bases which codes for incorrect 1 structure > can change shape of a.a