1/28
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
chromosomes made up of:
protein
nucleic acid
2 types of nucleic acid:
deoxyribonucleic acid
ribonucleic acid
nucleotides composed of 3 parts:
phosphate group
5-carbon sugar
cyclic nitrogen-containing base
DNA 4 bases
adenine
guanine
thymine
cytosine
RNA 4 bases
adenine
guanine
uracil
cytosine
purines- double rings
adenine
guanine
pyrimidines- single rings
cytosine
thymine
uracil
chemical polarity
bonds between 5’ carbon of deoxyribose in one nucleotides to 3’ carbon of deoxyribose in adjacent nucleotide
nucleotides joined by:
covalent bonds
adenine base pair
thymine
cytosine base pair
guanine
uracil base pair
adenine
adenine and thymine- hydrogen bonds
2
cytosine and guanine- hydrogen bonds
3
amount of base pairs per helical turn
10
complementary strand
nucleotide chain is flipped 180 degrees
stability results from:
lots of hydrogen bonds between base pairs
stacking forces or hydrophobic forces between adjacent base pairs
in cells, most dna is in a:
negative supercoil
chromatin
composed of dna and chromosomal proteins
2 major classes of proteins in chromatin:
histones
non histone chromosomal proteins
histones
proteins that function in the coiling of dna in chromosomes and regulation of gene activity
nonhistone chromosomal proteins
proteins that do not play a central role in packaging dna into chromosomes
nucleosome
small ellipsoidal bead in chromatin
composition of histones
20-30% of arginine and lysine
arginine and lysine function
pos. charged
makes histone charged
allows interaction with dna
side chain charge
are neg. charged due to oxygen atoms in the phosphate groups having loose electrons
histones function
primary: dna packaging
secondary: increase of decrease gene expression
composition of nonhistone proteins
varies widely among cell types in an organism
big, mixed group of proteins
nonhistone proteins function
primary: regulating gene expression
secondary: dna packaging