how common are proteins
Account for 50% of dry cell mass
7 things proteins function as
Enzymes
Storage
Transport molecules
Structural
Hormones
Defense
Contractile
what are proteins structures
- Built from 20 amino acids (protein monomers)
- Protein = 1 or more polypeptide chains
how to identify an amino acid structure
- alpha carbon in the middle (attached to the 4 different things)
- amino group - N2H / N3H
- carboxyl group (COOH / COO-)
- R group (Long chain of carbons that’s not the carbon alpha)
- H group (can be attatched to alpha carbon by bond or shown as CH)
how to know if the amino acid is charged, polar or nonpolar
- charged = R group has + or -
- nonpolar = R group is just made of C and H (hydrocarbon) OR the non C or H element has C either side of it
- polar = R group has element that is not just C and H + that element does not have C either side of it
polypeptide primary structure
Linear sequence of amino acids
polypeptide secondary structure
H bond interactions between elements of the generic peptide backbone
polypeptide tertiary structure
Relies on interactions (bonds) between R groups
polypeptide quaternary structure (not all proteins)
2 or more fully formed polypeptides come together
3 factors that affect protein structure
Salt conc
Temp
PH
what makes sure a polypeptides fold appropriately
Chaperonin
what allows scientists to see what structure protein is
Shooting x-ray beams through proteins to see its shape
where does protein synthesis occur
ribosome
nucleotide and nucleoside difference
nucleotide = phosphate
nucleoside = NO PHOSPHATE
how many hydrogen bonds do base pairs have
A -> T – 2 hydrogen bonds
C -> G – 3 hydrogen bonds
what are the PURINE base pairs
A, G
what are the PYRIMIDINE base pairs
C, T, U
whats the attached to the 1’ carbon in the sugar in a nucleotide
base
whats the attached to the 2’ carbon in the sugar in a nucleotide
OH (ribose) / H (dioxyribose - DNA)
whats the attached to the 3’ carbon in the sugar in a nucleotide
always Hydroxyl (OH)
whats the attached to the 4’ carbon in the sugar in a nucleotide
nothing
whats the attached to the 5’ carbon in the sugar in a nucleotide
Phosphate (if its a nucleoTIDE)
what do you call DNA strands that run in opposite direction
anti-parallel
how many hexagons does PURINE have
2 (5,6)
