The Digestive System

Question 1

Stages of Nutrition: getting energy from our food

Answer 1

1. Ingestive/Eating: Food is taken in by the body.
2. Digestive: Food is broken down.
3. Absorption: Digested food passes into the bloodstream.
4. Assimilation: Using the food in the cells of the body.
5. Elimination: Getting rid of undigested food.

Question 2

Digestion

Answer 2

There are two types: physical digestion and chemical digestion.

Question 3

Physical digestion

Answer 3

1. Taking large pieces of food and breaking them down into smaller pieces

Question 4

Chemical digestion

Answer 4

1. Involves the use of chemical called enzymes to break down food.
2. Enzymes are chemicals that speed up reactions without being used up in the reaction.
3. How enzymes work: Enzymes act on a substrate and breaks it down into products e.g.: substrate = starch, enzymes = amylase (saliva),a product = maltose (sugar).
4. Amylase in mouth.
5. Enzymes in the stomach.
6. Most chemical digestion happens in small intestine.
7. Biles made in liver to break down fats.
   Pancreas makes digestive juices which contains enzymes.

Question 5

Teeth: Incisors

Answer 5

1. At the front of the mouth
2. 4 upper and 4 lower
3. Used for biting the cutting food.

Question 6

Teeth: Canine

Answer 6

1. One at either side of the incisors.
2. 2 upper and 2 lower.
3. Grasp and tear food.

Question 7

Teeth: Pre-molar

Answer 7

1. 3 at either side of the canine.
2. 6 upper and 6 lower.
3. Grind and crush food.

Question 8

Teeth: Molar

Answer 8

1. 2 either side of the pre-molars.
2. 4 upper and 4 lower.
3. Grind and crush food.

Question 9

Herbivore

Answer 9

1. Only eats plants.
2. Very large incisors.
3. Large molars and pre-molars to chew grass.

Question 10

Carnivore

Answer 10

1. Only eats meat.
2. Large canine teeth.
3. Use the teeth to catch and tear their prey.

Question 11

Omnivore

Answer 11

1. Eats plants and meat.
2. Need all the different teeth.