B1.2 Proteins

draw an amino acid

draw a dipeptide

what is an essential amino acid

must be obtained through dietary sources and is essential for bodily function

what is a conditionally essential amino acid

They are essential at certain times e.g during illnesses or stress.

7 functions of polypeptides

structure, movement, transport, immunity, hormones, sensation, enzymes

what variables will result in denaturation

pH is not at optimum or temperature is too high

what is a primary structure of a protein

polypeptide chain of amino acids formed by condensation reactions

what is the secondary structure of a protein

alpha helix or beta pleated sheets formed by hydrogen bonding between N-H and C=O

what is the tertiary structure of a protein

hydrophobic/hydrophilic interactions, ionic interactions, polar interactions and disulphide bridges (cysteine) happen between R groups, forming 3D structures

what is the quaternary structure of a protein

when two or more separate proteins join to form one functional unit

examples of non conjugated proteins

insulin and collagen

example of conjugated protein

haemoglobin

is insulin a globular or fibrous protein

globular

is collagen a globular or fibrous protein

fibrous

what technology allows us to view protein structure

cryogenic electron microscopy