nucleic acids Flashcards
1
Q
what are ribosomes formed from
A
from RNA and proteins
2
Q
components of DNA
A
deoxyribose sugar
phosphate
base c, g t, a
3
Q
components of RNA
A
ribose sugar
phosphate
bas c, g , a. u
4
Q
what bond is formed when two nucleotides form together
A
phosphodiester
5
Q
describe the structure of the DNA
A
it is long
it is double stranded
6
Q
describe the structure of RNA
A
it it short and straight chained
strands are anti parallel
strands held by hydrogen bonds
7
Q
describe semi-conservative replication
A
- DNA Helicase breaks hydrogen bonds between bases, unwinds double helix
- = two strands which both act as templates
- Free floating DNA nucleotides attracted to exposed bases via specific complementary base pairing, hydrogen bonds form (adenine-guanine; guanine-cytosine)
- DNA polymerase joins adjacent nucleotides on new strand by condensation, forming phosphodiester bonds (= sugar phosphate backbone)
- Replication is semi-conservative – each new strand formed contains one original / template strand and one new strand
- Ensures genetic continuity between generations of cells
8
Q
DNA structure in relation to its function
A
- helical(coiled)—-> compact
- has weak hydrogen bond between strands—–> so the helicase can break it up
