8 - DNA, genes and protein synthesis Flashcards
1
Q
DNA helicase
A
- breaks hydrogen bonds between bases
- unwinds and separates two strands of DNA
2
Q
DNA polymerase
A
- joins together adjacent nucleotides
- forms phosphodiester bonds (in backbone)
3
Q
structure of ATP
A
- one adenine
- one ribose
- three phosphate group
4
Q
how does ATP store and release energy
A
- bond between phosphate groups UNSTABLE
- so low activation energy (easily broken)
- when bonds break they release energy
5
Q
terminal phosphate
A
furthest last phosphate
6
Q
ATP energy release equation
A
ATP + H2O → ADP + Pi + free energy
7
Q
features of DNA in relation to replication
A
- weak H bonds between bases (allow two strands to sepetate/ unzip)
- two strands (so both act as templates)
- complementary base pairing (accurate replication)
8
Q
evidence for DNA as polymer (1 mark)
A
repeating units of nucleotides
9
Q
A
A
adenine
10
Q
G
A
guanine
11
Q
T
A
thymine
12
Q
U
A
uracil
13
Q
C
A
cytosine
14
Q
complementary base pairing rules
A
A – T/U (2 Hydrogen bonds)
C – G (3 Hydrogen bonds
15
Q
formation of nucleotide
A
- pentose sugar and base join together (condensation reaction) = NUCLEOSIDE + water
- phosphate group + nucleoside (condensation reaction) with ester bond = NUCLEOTIDE + water
16
Q
formation of polynucleotide
A
- nucleotides join together (condensation reaction)
- phosphodiester bond between PHOSPHATE of one nucleotide and PENTOSE SUGAR of another nucleotide
17
Q
antiparallel direction
A
two DNA chains runs in opposite directions