amino acids, peptides, proteins

Question 1

what is a proteins function

Answer 1

transport, structure, storage

Question 2

what is an amino acid structure

Answer 2

N terminal and C terminal - carbon is chiral except in glycine

Question 3

how do amino acids behave in water

Answer 3

if side chain is polar - hydrophilic - on protein surface

if side chain is non polar - hydrophobic - buried in core

Question 4

what are the effects of ph on amino acids

Answer 4

H is lost if in base

H is gained if in acid

Question 5

what is enkephalin

Answer 5

a pentapeptide endorphin
natural brain opiod
binds to opiod recptors - affects pain reception

Question 6

what are the levels of protein structure

Answer 6

primary - amino acid sequence
secondary - alpha helix, hydrogen bonding
tertiary - folding, 3d shape, function derived
quarternary - multiple peptides together

Question 7

what are fibrous and globular proteins

Answer 7

fibrous - hair, primary structure repetitive

globular - intricately folded so that sidechains are sheltered eg enzymes

Question 8

what happens to proteins at high temps and ph

Answer 8

denaturation

hydrogen bonds break - secondary and tertiary structure affected so function is affected

Question 9

what is the isoelectric point

Answer 9

the ph that makes the overall charge of a protein zero

if ph is lower, charge is positive
if ph is higher, charge is negative

when charge is zero proteins aggregate - least soluble form

Question 10

what are lipoproteins, glycoproteins, and nucleoproteins

Answer 10

lipoproteins - carry fat around blood

glycoproteins - proteins with oligosaccharides eg antibodies, receptors, hormones

nucleoproteins - ribosomes, virus particles