carbohydrates revision 11.03.25

What are carbohydrates?

Carbohydrates are organic molecules composed of carbon, hydrogen, and oxygen, primarily used as energy sources.

Monosaccharides

Simple sugars with the general formula (CH2O)n, such as glucose and fructose, which are the building blocks of carbohydrates.

Disaccharides

Carbohydrates formed by the union of two monosaccharides, such as sucrose (glucose + fructose) and lactose (glucose + galactose).

Examples of polysaccharides

Starch, glycogen, and cellulose, which serve as energy storage or structural components.

Starch

A polysaccharide made up of glucose units, serving as the primary energy storage in plants.

Glycogen

A highly branched polysaccharide that acts as the main energy storage form in animals.

Cellulose

A structural polysaccharide composed of beta-glucose units, providing rigidity in plant cell walls.

The role of carbohydrates in energy

Carbohydrates provide a readily available source of energy, especially in cellular respiration.

Hydrophilic nature of carbohydrates

Carbohydrates are typically soluble in water, which aids in their transport within biological systems.

Polysaccharides as structural units

Polysaccharides like cellulose and chitin serve crucial structural roles in plants and fungi, respectively.

What monosaccharides make up maltose?

Maltose is composed of two alpha glucose molecules.

What monosaccharides are in sucrose?

Sucrose is made up of alpha glucose and fructose.

What are the monosaccharides that form lactose?

Lactose consists of alpha glucose and beta galactose.

What monosaccharides make up cellobiose?

Cellobiose is formed by two beta glucose molecules.