DNA polymerisation

Question 1

How do polymers of DNA form?

Answer 1

• two nucleotides link together when an -OH group of phosphate on one nucleotide reacts with an -OH group on another nucleotide
• eliminate a water molecule

Question 2

What does this arrangement form?

Answer 2

• sugar - phosphate back bone
• bases attached
• bases along this chain may be in any oirder
• this leads to the variety

Question 3

What code is produced? How is it interp[reted?

Answer 3

• 4 letter code
• cells can read it - holds instructions
• chemists can now read the sequence of bases
• this is DNA sequening

Question 4

What is the structure of a DNA molecule?

Answer 4

• 2 strands held together by hydrogen bonding
• forms a double helix

Question 5

How is the helix formed?

Answer 5

• only A and T can join together
• only G and C can join together
  
  • only these can form effective hydrogen bonds between each other
• it is complementary
  
  • so that the molecules wind
  • due to the size of the molecules

Question 6

What did Watson and Crick do?

Answer 6

• shown DNA was helical
• through X-ray diffraction