Proteins are made up of the chemical composition of Hydorgen, Oxygen, Nitrogen and Carbon.

Nitrogen is used for growth.

Essential amino acids cannot be made in the body.
We can only get them from food. Examples- Valine, lyceine, luecine, methonine, tryptophan, isoleucine, Proline, Cysteine.

Protein structure

Primary-order and sequence- draw basic chain with shapes give examples

Secondary-further linking-disulphide link and hydrogen bond. Give examples for protein this happens in.

Tertiary-further cross-links; 3D shape- 2 types fibrous and globular. Examples.

Functions

Structural-growth and repair

Physiologically active-produce hormones, enzymes, antibodies

Nutrients-essential amino acids; excess energy