Glycine is named for its sweet taste (glykos means sweet in Greek), and tyrosine is named as it was first obtained from cheese (tyros means cheese in Greek). Trivial names often reflect the properties or sources of the compounds.

Amino acids are classified as α, β, γ, δ, etc., based on the relative position of the amino group with respect to the carboxyl group. Only α-amino acids are obtained on the hydrolysis of proteins.

Proteins, the most abundant biomolecules in living systems, are crucial for the structure and functions of life, required for growth and maintenance of the body. Chief sources of proteins in the diet include milk, cheese, pulses, peanuts, fish, and meat.

Carbohydrates function as storage molecules in the form of starch in plants and glycogen in animals. Industrially, carbohydrates contribute to textiles, paper, lacquers, and breweries, providing raw materials for these important industries.

Carbohydrates are essential for life in plants and animals, forming a major part of our food. Honey, known for its high carbohydrate content, has been used as an instant source of energy in the ayurvedic system of medicine.