Protein
A large biomolecule made of one or more chains of amino acids folded into a specific three-dimensional shape.
Unit
g/mol
In depth
Proteins perform almost every task in the cell — catalysis, transport, structure, signalling and defence — and their function follows directly from their folded shape. That shape is determined entirely by the amino acid sequence, itself specified by a gene.
Examples in the real world
Haemoglobin transporting oxygen, collagen giving tendons strength, and antibodies recognising pathogens.