protein

Protein

An organic macromolecule composed of amino acids linked by peptide bonds.

Amino Acid

A molecule composed of an amino group and a carboxyl group, together with a variable side chain that functions as the monomer of protein.

Peptide Bond

A covalent bond between two amino acids that forms by dehydration synthesis.

Polypeptide

A protein strand containing fewer than about 100 amino acids.

Denaturation

A change in the structure of a molecule through physical or chemical means.

Substrate

A chemical reactant that binds to an enzyme at its active site.

Active Site

The region of an enzyme where the substrate binds.

Protein Characteristics

Proteins are critical components of all tissues and organs, composed of amino acids. They include keratin, collagen, enzymes, antibodies, neurotransmitters, and hormones.

Structure of Proteins

Proteins are polymers made from 20 different amino acids, each containing an amino group, carboxyl group, and a variable side chain (R-group).

Essential Amino Acids

Nine of the 20 amino acids cannot be synthesized by the body and must be obtained from the diet.

Protein Folding

Proteins have four structures: primary (sequence of amino acids), secondary (alpha helices and beta-pleated sheets), tertiary (3D shape), and quaternary (multiple polypeptides).

Denaturation in Proteins

Denaturation is the process where proteins lose their functional shape due to environmental factors like heat or acidity.

Function of Enzymes

Enzymes are proteins that catalyze chemical reactions by binding substrates at active sites, forming an enzyme-substrate complex.

Other Functions of Proteins

Proteins serve various functions, including acting as hormones, buffers, fluid regulators, transporters, and sources of energy.