What are the 4 levels of protein strucutre
primary, secondary, tertiary, quaternary
what are primary proteins
amino acid sequences
what are secondary proteins
stable folding patterns within a polypeptide
what are tertiary protein structures
full 3D conformation
what are quaternary protein structures
complex formed between 2+ polypeptide chains
amino acids are joined together through ___ ___ to form peptide bonds
condensation reactions
how are secondary structures stabilized
hydrogen bonds that form between the amino and carbonyl groups of the polypeptide backbone
what is the alpha helix
carbonyl group of one peptide bond is hydrogen bonded to the amino group of a peptide bond FOUR amino acids away
alpha helixes make a complete turn everry ___ amino acids
3.6
what forms a coiled-coil
amphipathic alpha helices
what is a Beta sheet
polupeptide strands that are extended, giving the packbone a pleated shape
what is a modular structure
a polypeptide with alpha helix regions and beta sheet regions
what is protein domain
any segment of a polypeptide chain that can fold independently into a compact, stable structure
protein folding in a cell is often assisted by ___ ___ or ___
molecular chaperones, chaperonins
extracellular proteins are stabilized wia
crosslinking
this type of bond does not change protein conformation, but stabilizes its structure
disulfide
a defect in protein folding can lead to ___
aggregation
aggregation can be seen in these disorders (3)
alzheimer’s, huntington’s, Prion Diseases
