Structure of proteins II Flashcards
how are beta strands held together
interchain hydrogen bonding of the backbone C=O and N-H groups
antiparallel beta sheets
adjacent strands run in opposite directions
parallel beta sheets
adjacent strands run in same directions
what are reverse turns stabilized by
hydrogen bonding, salt bridges, metal ions, disulfide bonds
what is often found in reverse turns
proline and glycine
what is tertiary structure
3D folded structure
prosthetic groups
organic molecules that are permanently bound to the protein
apoproteins
lack prosthetic group whilst the final functional molecule is said to have the native strucutre
what is unqiue about myoglobin
has high affinity for oxygen
heme group contains an Fe2+ ion that is required for oxygen binding
secondary structural elements are all alpha helices
what are some ways that the native structure of proteins can be denatured
incrased temp
detergents
pH extreme
agents like urea and guanidinium hydrochloride
how does denaturing work
disrupt non-covalent bonds that maintain folded conformation of the protein
how does protein foldign occur
favored pathways in a cooperative manner
what is protein folding driven by in an aqueous environement
strong tendency of hydrophobic residues to be excluded from water
forces that contribute to stabilizing protein structure
cystine disulfide bridges
hydrogen bonding
ionic interactions
hydrophobic forces
where are salt bridges and hydrogen bonding usually taking place
internal portion of molecule or interfaces btwn polypeptide chains