Digestion

Question 1

Why do we need food (3)

Answer 1

To supply us with “fuel” for energy
To provide materials for growth and to repair tissues
To help fight disease and keep our bodies healthy

Question 2

What are the 7 types of nutrients in all food

Answer 2

Carbohydrates
Lipids
Proteins
Water
Fibre
Minerals
Vitamins

Question 3

What does too much sugar cause (2)

Answer 3

Sugar gets stored as fat which leads to obesity

Causes tooth decay as the bacteria in the mouth feeds on the sugar and breaks it down releasing acid which dissolves the enamel

Question 4

Why do we need carbohydrates

Answer 4

Used to release energy during respiration

Question 5

What are lipids used for

Answer 5

To make cell membranes, insulation, protection of organs, energy store

Question 6

What can too much fat lead to

Answer 6

Heart disease

Question 7

What do all cells contain

Answer 7

Protein

Question 8

Why do we need proteins (5)

Answer 8

For growth and repair of tissues
Hormones
Enzymes
Antibodies
Transport

Question 9

If we are deficient in proteins what do we develop

Answer 9

A disease called kwashiorkor

Question 10

What is the purpose of digestion

Answer 10

To break food into molecules that are small enough to be absorbed into the blood stream

Question 11

What is mechanical digestion and examples

Answer 11

Digestion by physically breaking down food into smaller pieces without enzymes

Mouth and teeth chewing food
Stomach churning food

Question 12

What is chemical digestion

Answer 12

Digestion using enzymes

Question 13

Which enzyme is excreted from the salivary glands and what is it used to break down into what

Answer 13

Amylase is used to break down starch into maltose

Question 14

Which enzyme is found in the stomach and what does it break down into what

Answer 14

Protease is used to break down proteins into amino acids

Question 15

Which enzyme is found in the small intestine that was made in the pancreas and what does it break down into what

Answer 15

Amylase breaks down starch into maltose
Protease breaks down proteins into amino acids
Lipase breaks down fat into glycerol and fatty acids

Question 16

What is digestion

Answer 16

The chemical and mechanical break down of food

Question 17

What does digestion do

Answer 17

Converts large insoluble molecules into small soluble molecules which can be absorbed into the blood

Question 18

What is ingestion

Answer 18

The consumption of a substance

Question 19

What is absorption

Answer 19

Taking molecules into the bloodstream

Question 20

What happens in the mouth (4)

Answer 20

Food is ingested

Mechanical digestion- teeth are chewing (increases surface area)

Chemical digestion- amylase in saliva breaks down starch into maltose

Food is rolled by the tongue into a bolus and swallowed

Question 21

What happens in the oesophagus and wth is it

Answer 21

It is the food pipe connecting the mouth and the stomach

Food is moved down here by muscular contractions know as peristalsis

Question 22

What is the stomach what types of digestion occur there

What else?

Answer 22

Large muscular bag

Mechanical digestion- churns food

Chemical digestion- gastric juice is excreted

Gastric juice contains pepsin which is activated by HCl as it provides optimum pH 2. Also contains HCl which kills bacteria

Goblet cells produce mucus as a lining to prevent damage from HCl

Question 23

What is the duodenum what type of digestion occurs there

Answer 23

First section of small intestine where digestion is completed

Chemical digestion - pancreatic juice contains maltase, pancreatic amylase, protease and lipase

And bile

Question 24

What is bile

Answer 24

Made in the liver, stored in the gall bladder

Function is to emulsify large lipids into small fat droplets, increasing the surface area for the enzymes to work

Question 25

What pH are bile and pancreatic juice and why

Answer 25

Alkali to neutralise the good covered in stomach acid

Question 26

What is the ileum and what occurs there

Answer 26

Part of the small intestine

Most of absorption takes place here

Question 27

How does absorption take place

Answer 27

Passively or by active transport

Question 28

How is the ileum adapted to it’s function

Answer 28

Highly folded finger like projections called villi

• increases surface area
• thin walls decrease diffusion pathway
• micro villi on the surface
• rich blood supply

Question 29

What is assimilation

Answer 29

A process which uses products of digestion to build new molecules

Question 30

What happens after food has been digested and absorbed

Answer 30

Assimilated into the body

Question 31

What type of stuff is left to go into the colon and what is the colon, what is the main role

Answer 31

Part of the large intestines

Undigested food, mucus, dead cells, bacteria

Reabsorbtion of water and mineral ions

Question 32

What is the rectum and what is its role

Answer 32

In the large intestines

Where faeces are stored until it is egested from the body via the anus

Question 33

What is egestion

Answer 33

The discharge of Undigested material from the digestive system