Food And Digestion

Question 1

What size molecules does food need to be in and why?

Answer 1

Small molecules, the food must be able to get through the wall of the gut and into the blood system

Question 2

How is food converted into a suitable size so it can be transported into the blood?

Answer 2

Digestion process

Question 3

What are the substances that need to be digested (3)

Answer 3

Proteins
Fats
Complex carbohydrates (starch)

Question 4

How do you test for starch?

Answer 4

Iodine solution

If present, blue black colour appears

Question 5

How do you test for glucose?

Answer 5

Benedict’s solution, boil at 60-80 degrees for 10-15 mins

If present, it will turn brick red

Question 6

How do you test for protein?

Answer 6

Add an equal amount of sodium hydroxide, then a few drops of copper sulphate solution

If present lilac colour appears

Question 7

What is often used as a model gut in experiments?

Answer 7

Visking tubing

Question 8

Name all the parts of the digestive system

Answer 8

Mouth, oesophagus, liver, stomach, gall bladder, bile duct, pancreas, small and large intestine,anus

Question 9

What do enzymes do in the digestive system?

Answer 9

Break down the different food groups

They speed the process of breaking down large insoluble molecules to small soluble molecules.

Question 10

Name the enzymes found in the gut

Answer 10

Carbohydrase-break down carbohydrates
Protease-break down proteins
Lipase-break down fats

Question 11

What is the function of the mouth!

Answer 11

Breaks down food by chewing. Carbohydrase in saliva breaks down starch

Question 12

Function of the stomach

Answer 12

Acid in the stomach kills bacteria. Stomach produces protease and lipase enzymes

Question 13

Function of the pancreas

Answer 13

Produces protease, lipase and carbohydrase enzymes. These enzymes act in the small intestine

Question 14

Function of the small intestine

Answer 14

Digestion is completed by carbohydrase enzymes in the small intestine. The food is absorbed in the second half of the small intestine

Question 15

Function of large intestine

Answer 15

Water from the digestive juices is re absorbed into the blood

Question 16

What is bile?

Answer 16

A liquid produced in the liver and stored in the gall bladder. It is secreted down the bile duct into the small intestine.

Question 17

What does bile do?

Answer 17

Helps in the digestion of fats. It emulsified fats and breaks them into small droplets, giving a bigger surface area for lipase enzyme to act on

Question 18

Explain peristalsis

Answer 18

Food is moved along the small intestine by peristalsis. This involves the contraction of circular gut muscles behind the food and the relaxation of the muscles in front of the food

Question 19

What are fats made up of?

Answer 19

Fatty acids and glycerol

Question 20

What are proteins made of?

Answer 20

Amino acids

Question 21

What is starch made up of?

Answer 21

A chain of glucose molecules

Question 22

What do fatty acids, glycerol and glucose provide!

Answer 22

Energy

Question 23

What does amino acids do for the body?

Answer 23

Build proteins in the body

Question 24

What form does the food need to be in and why?

Answer 24

Soluble in water so it can dissolve in the blood