structure of DNA Flashcards
1
Q
the two strands of DNA
A
- are anti parallel to each other and run in opposite directions
- are twisted around each other to form a double helix
2
Q
what does DNA consist of
A
- 2 long chains of nucleotides:
(deoxyribose sugar, phosphate, base) - sugar phosphate backbone
base pairing - hydrogen bonds
- deoxyribose and phosphate at 3’ to 5’
3
Q
what forms genetic code
A
the base sequence of DNA
4
Q
how are nucleotides joined
A
by strong covelant bonds between deoxyribose and phosphate forming sugar-phosphate backbone
5
Q
how are 2 strands of DNA held together
A
by weak hydrogen bonds between complementary base pairs
6
Q
histones
A
DNA tightly coiled and packaged around bundles of other proteins
7
Q
prokaryotes
A
in bacteria
- single circular chromosome, smaller circular plasmids
8
Q
eukaryotes
A
in yeast cells, plants, animals, fungi
- linear chromosomes, tightly coiled and packaged with other proteins (histones), contains plasmid
