MHS module 1- proteins p3

what are proteins:

most abundant and important organic molecules

contain basic elements: carbon, hydrogen, oxygen and nitrogen

20 amino acids are the monomers combined to form proteins

function of proteins:

support: structural proteins

movement: contractile proteins

transport: carrier proteins

buffering: regulation of pH

metabolic regulation: enzymes

coordination and control: hormones

defense: antibodies

describe protein structure:

long chain of amino acids:

• central carbon atom

• hydrogen atom

• amino group (NH2)

• carboxyl group (COOH)

• side chain/R group

how is a protein formed

dehydration synthesis: amino group of one amino acid and the carboxyl group of another amino acid

forming a peptide bond resulting in a peptide (polypeptide)

describe the 4 structures of proteins

primary structure:

• sequence of amino acids along a polypeptide

secondary structure:

• hydrogen bonds form spirals or pleats

tertiary structure:

• coiling anf folding produce 3D shape

quaternary structure:

• final protein complex produced by interacting polypeptide chains

what are enzymes:

• catalysts

• lower activation energy of a chemical reaction

• no changed or used up in the reaction

• substrates bind to an active site on an enzyme

what do enzymes exhibit:

specificity: catalyse only one type of reaction

saturation limits: become saturated

regulation: by other cellular chemicals

function of cofactor:

• ion/molecule that binds to an enzyme before substrates can bind

function of coenzyme:

• non protein organic cofactors (vitamins)

affect of pH and temperature on function of enzyme

denaturation: change in shape/ loss of function due to heat/pH