biology-paper 1 orgnisation

Gcse aqa biology the digestive system

what is a tissue

A tissue is a group of cells with a similar structure and function.

What is an organ?

An organ is a group of tissues working together for a specific function.

What is an organ system?

An organ system is a group of organs working together to form an organism.

Give an example of an organ and the tissues it contains.

The stomach, which contains muscle tissue and glandular tissue that releases enzymes

What are the three main nutrients found in food?

Carbohydrates, proteins, and lipids .

Why do food molecules need to be digested?

They are too large to be absorbed into the bloodstream, so they must be broken down by enzymes.

What is the function of enzymes in digestion?

Enzymes break down large food molecules into smaller molecules that can be absorbed.

What happens to food in the mouth during digestion?

It is chewed, and enzymes in saliva begin breaking down starch into smaller sugar molecules.

What happens to food in the stomach?

Enzymes begin digesting proteins, and hydrochloric acid helps with protein digestion. The stomach muscles churn food into a fluid.

What does the pancreas do in digestion?

It releases enzymes that continue breaking down starch, proteins, and lipids

What is the role of bile in digestion

Bile, released by the liver, speeds up lipid digestion and neutralizes stomach acid.

Where does the absorption of digested food molecules occur?

In the small intestine, by diffusion or active transport.

What happens in the large intestine?

Water is absorbed into the bloodstream, and feces are formed and excreted

What happens to the products of digestion after absorption?

They are used to build new carbohydrates, lipids, and proteins. Some glucose is used in respiration.