protein structure Flashcards
what is proteins primary structure?
simples order/sequence of amino acids
what are 3 ionic interactions that hold proteins together?
van der waals, electrostatuc attractions, hydrogen bonds.
what is proteins secondary structure?
the local folding of primary amino acid chain
what are 3 main secondary structures?
a-coil, b-sheet, random coil
what is structure of a-helix?
7 amino acids per 2 turns (heptad)
intrachain H bonds on each 4th residue
what are 2 types of B-sheet structure?
parallel
antiparallel
what is a proteins tertiary structure ?
way in which secondary structure elements pack together with a protein and between subdomains of a protein
where is tertiary structure of a protein?
relationship between proteins in a multimeric complex
name 4 post-translational modifications
disulphide bonds, lipid modification, proteolysis, glycosylation
in which proteins are disulphide bonds usually found?
in proteins exposed to extreme environments as S-S bonds provide stability.
what is proteolysis post translational modifications?
can cleave hormones and enzymes for a mature form. can cleave AUG/ initiation codon.
what do lipid modifications do?
attach lipophilic covalent attachments so proteins can attach to membranse
what is glycosylation?
carbohydrate modification - extracellular protein modification
