DNA and chromosomes Flashcards
1
Q
gene
A
segment of DNA that encodes for a protein
2
Q
chromsome
A
continuous piece of DNA
3
Q
Watson and Crick
A
DNA double helix
4
Q
Chargaff’s Rule
A
A=T & G=C
A+G=T+C
5
Q
phosphodiester bonds
A
5’ joined to 3’
6
Q
DNA/RNA composition
A
- one base
- sugar (deoxyribose or ribose)
- a phosphate
7
Q
nucleoside
A
base + pentose
8
Q
nucleotide
A
base + pentose +phosphate
9
Q
B-DNA
A
normal form of DNA
-right handed
10
Q
Z-DNA
A
Zigzag, left-handed
-longer and thinner than B-DNA
11
Q
A-DNA
A
right-handed
- shorter and thicker than B-DNA
- made artificially by dehydrating B-DNA
12
Q
topoisomerases
A
enzymes that regulate the over-winding or under-winding of DNA
13
Q
positive supercoiling
A
tight winding of the double helix
-reduces chances of interaction
14
Q
negative supercoiling
A
unwinding of the double helix
-increases access to proteins involved in replication or transcription
15
Q
genome
A
one complete copy of all the genetic information of an organism
