Digestion And Digestion System

Question 1

Why do we digest food?

Answer 1

Nutrients the body needs contains insoluble molecules. These need to be broken down (by digestion)

Question 2

What is digestion?

Answer 2

The breaking down of food into smaller parts

Question 3

Name the 5 stages of digestion

Answer 3

Ingestion, digestion, absorption, assimilation, egestion.

Question 4

What is ingestion?

Answer 4

Food is taken through mouth

Question 5

What is digestion?

Answer 5

Food is broken down into soluble molecules. Starts in mouth and continues to stomach +small intestine

Question 6

What is absorption?

Answer 6

Soluble products absorbed into bloodstream and transported around the body, (happens in ileum in small intestine)

Question 7

What is assimilation?

Answer 7

Soluble products are taken into cells where they are used.

Question 8

What is egestion?

Answer 8

Removal of waste food (defecation) via anus

Question 9

What are the body parts included in the process of digestion?

Answer 9

Mouth, oesophagus, stomach, small intestine, large intestine

Question 10

What happens in the mouth?

Answer 10

Food is chewed and cut up into small pieces.
Saliva is added

Question 11

What does saliva do and contain?

Answer 11

Lubricates food to make it easier to swallow
Contains amylase which digests starch

Question 12

What happens in the oesophagus and what is it?

Answer 12

Tube that carries food from mouth to stomach. Doesn’t carry out digestion, but has muscular walls to allow food to be pushed along.

Question 13

What happens in the stomach?

Answer 13

Mechanical and chemical digestion takes place.
Muscular walls of stomach churn food and food is then mixed with digestive juices in stomach. (MECHANICAL DIGESTION)
Protease enzymes break down insoluble proteins into small, soluble amino acids. (CHEMICAL DIGESTION)
walls of stomach produces hydrochloric acid
Results in fluid of stomach having pH 2/3
This ensures bacteria on our food are killed and won’t make us sick.
also pH stomach enzymes work best with

Question 14

What happens in the walls of the stomach?

Answer 14

Hydrochloric acid is produced
(Results in fluid of stomach having pH 2/3)
This ensures bacteria on our food are killed + won’t make us sick.
Also pH stomach enzymes work best with.

Question 15

What happens in small intestine?

Answer 15

In lower part (ileum), features are found that allow soluble products of digestion to be absorbed.
Number of features increase surface area for absorption.

Question 16

Give some properties of the small intestine

Answer 16

Very long
Walls are folded
Walls covered in villi
Walls are very thin + 1 cell thick
Very good blood supply to carry away products of digestion

Question 17

What happens in large instestine?

Answer 17

Water added to food during digestion is reabsorbed.
Results in formations of faeces (stored in rectum before passing out of body, via anus, during egestion.)