2. DNA Structure 2 Flashcards
1
Q
explain the basic structure of a double helical DNA
A
- two strands of DNA wrapped around each other
- bases in the centre, sugars and phosphates on the outside
- ‘watson-crick’ hydrogen bonding between pairs of bases
2
Q
why are there major/minor groves in the double helix?
A
because of the asymmetric attachemnt of bases on C1 (N-glycosidic bond)
major groves - bases are far apart
minor grove - bases close together
3
Q
where are the hydrgoen bonds in DNA?
A
between the bases
4
Q
where are the hydrophobic interactions in DNA?
A
they are in the rings of the bases. it stabilises the structure
so hydrophobic interactions are between stacked base pairs. this impacts stability of the helix
5
Q
how do proteins recognise the sequence of base pairs in double stranded DNA?
A
by interacting with groups on the edges of the base pairs that are not involved in base pairing (eg a ketone group)
