Science Year 8 Digestion Key Words

Key Words

Definition

Digestion

Breaking down of our food.

Digestive system

All of the organs that help us digest our food. Mouth, oesophagus (gullet), stomach, small intestine, large intestine, rectum, anus.

Diet

Someone’s diet is a description of all the different foods they eat.

Balanced diet

A diet that has the right amount of all the different food groups.

Food groups

These are the 7 different chemicals that combine together in our food. They include:

Proteins, carbohydrates, fats (lipids), vitamins, minerals, fibre, water.

Obesity

This is where someone puts on so much weight their health is affected.

Mouth

Food broken down into smaller particles, saliva added.

Saliva

Contains amylase that digests starch into glucose.

Lubricates food so moves down gullet smoothly.

Oesophagus (gullet)

Muscular tube that pushes food down to the stomach.

Stomach

Muscular bag that contains hydrochloric acid (HCl, pH2) and protease.

The protease digests proteins into amino acids.

Small intestine

Long tube where small digested food molecules are absorbed through the wall of the small intestine into the bloodstream.

Pancreas

This organ releases all three enzymes (amylase, protease, lipase) into the small intestine.

Enzyme

A chemical produced by the digestive system that digests your food.

Protein          →                 amino acids

Lipase (fats)            →              fatty acids and glycerol

Starch              →               glucose

Large intestine

Water in absorbed through its wall into the blood stream.