Key learning points

1. Carbohydrates, proteins and fats in food are broken down by digestion into smaller molecules that can be absorbed.
2. Nutrients are absorbed into the blood, which transports them around the body to where they are needed by cells.
3. The molecules of some nutrients are small enough to be absorbed into the blood by diffusion.
4. Adaptations of the small intestine lining that increase the amount of absorption.

Keywords

• Blood - Blood is a liquid which transports nutrients and waste around the body.

• Absorption - Absorption is the process of moving nutrients from the digestive system into the blood.

• Surface area - Surface area is the area of a surface.

• Diffusion - Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.

• Circulatory system - The circulatory system includes the heart and blood vessels through which blood can move.

Common misconception