unit 1.2 structure and replication of DNA

Question 1

what are the function of the DNA

Answer 1

found in nucleus
base sequence of DNA forms genetic code
DNA codes for proteins which provide the cell with certain characteristics and functions

Question 2

what’s the structure of DNA

Answer 2

DNA is 2 stranded = double stranded helix
each strand is made of nucleotides
which consist of
- deoxyribose sugar
- phosphate
- bases
runs antiparallel to each other
deoxyribose (3’ end)
phosphate (5’end)
sugar from deoxyribose sugar bond with phosphate form a sugar phosphate backbone (strong bond)
weak hydrogen bond are between the bases to hold the strands together

Question 3

primers are what

Answer 3

DNA primers are short stranded nucleotides which bind to the template in the 3’ end allowing DNA polymerase to add DNA nucleotides

Question 4

what’s the process of DNA replication

Answer 4

1. double stranded helix broken form 2 template strand
2. primer bind to 3’ end of template strand. allowing polymerase to add nucleotides using complementary base pairings in the direction to the deoxyribose of the 3’ end of new strand
3. replication continues on leading strand as its heading in the direction from 5’ to the 3’ end
4. lagging strand is replicated in fragments and so ligase an enzyme joins the fragments together

Question 5

polymerase chain reaction (PCR)

Answer 5

Amplifies section of DNA using complementary primers for specific target sequences

Question 6

process of PCR

Answer 6

1. DNA heated to 95º strands are separated
2. cooled to 55º primers bind to target sequence
3. heated to 75º polymerase is added to replicate section of DNA