L14-15: Protein Structure and Function Flashcards
how are amino acids categorised 4 groups
polar unpolar - acidic - basic - uncharged
what is involved in the peptide bond joining aa
not side chains
b/w N and C terminus
are polypeptides flexible
not flex about peptide bond
but flexi about inter
what restricts conformations of polypeptides
non covalent bonding
explain proteins hydrophobic interactions when determine protein confirmation
hydrphobic core = nonpolar stay on inside
polar side chains stay on outside forming h bonds with water
what acts as stabilising bonds in some protein confirmations
disulphide bonds
what are the two folding motifs of 2ndary structures
a helix
beta pleated sheets
explain a helix structure
Carbonyl oxygen of peptide bond = hydrogen bonded to amid hydrogen of amino acid 4 residues away
explain b sheets structure
laterally packed b strand (parallel or anti)
what secondary structure is in transmembrane proteins
a helix
what is a protein domain
region of polypeptide that can fold independly into stable structure
as an organisms increases in complexity, what happens to number of domains
increases
what ligands do antibodies bind and what is the result
antigens= destruction
what are keratin monomers
fibrous proteins= assemble into intermediate filaments
function of enzymes protease
hydrolyse peptide bonds b/w aa
function of enzymes polymerase
catalyse polymerisation such as synthesis of DNA.RNA
function of enzymes kinase
catalyse addition of phosphate groups to molecules
function of enzymes phophatase
catalyse hydrolytic removal of phosphate group from molecule
two ways enzymes are regulated
by binding other molecules
by phosphorylation
how does motor proteins generate movement
movement coupled with hydrolysis of ATP
what is the movement of kinesis and dynein
move cytoplasmic components (cargo) along microtubules
atp hydrolysis occurs at head regions
