2b.1 - Enzymes

Question 1

What are enzymes?

Answer 1

Catalysts produced by living things

Question 2

What is a catalyst?

Answer 2

It is a substance which increases the speed of a reaction, without being changed or used up in the reaction

Question 3

What is an enzyme made of?

Answer 3

Protein

Question 4

What are proteins made up of?

Answer 4

Chains of amino acids

Question 5

Other than catalysts, whet else does protein make up? (3)

Answer 5

• Structural componants of tissues, hormones and antibodies

Question 6

What do chemical reactions usually involve?

Answer 6

Thing being joined together or split up

Question 7

What conditions need to be right for enzymes to work? (2)

Answer 7

• The right temperature

- The right PH

Question 8

Why do enzymes need to be the right temperature? (2)

Answer 8

• Increasing the temperature increases the rate of reaction at first
• But if it gets too hot it becomes denatured

Question 9

What temperature do enzymes in the body work best at?

Answer 9

37C

Question 10

Why do enzymes need to be kept at the right PH?

Answer 10

If the PH is too high or too low it will denature enzymes

Question 11

What PH do enzymes work best at? (2)

Answer 11

• Usually 7 but not always

- Enzymes, like pepsin in the stomach, work best in acidic conditions

Question 12

What does amylase do?

Answer 12

Converts starch into sugars

Question 13

What does protease do?

Answer 13

Converts proteins into amino acids

Question 14

What does lipase do?

Answer 14

Converts lipids into glycerol and fatty acids

Question 15

Where is amylase made? (3)

Answer 15

• Salivary glands
• Pancreas
• Small intestine

Question 16

Where is protease made? (3)

Answer 16

• The stomach (it’s called pepsin there)
• The pancreas
• The small intestine

Question 17

Where is lipase made? (2)

Answer 17

• The pancreas

- The small intestine

Question 18

What are lipids?

Answer 18

Fats and oils

Question 19

What does bile do?

Answer 19

Neutralises the stomach acid and emulsifies fats

Question 20

Where is bile produced?

Answer 20

The liver

Question 21

Where is bile stored?

Answer 21

The gall bladder

Question 22

Why is bile needed? (2)

Answer 22

• The hydrochloric acid in the stomach makes the stomach too acidic for the enzymes. Bile is an alkali so neutralises the acid
• It breaks fat into tiny droplets which give it a smaller surface area. This makes digestion faster

Question 23

Why are the salivary glands a significant part of the digestive system?

Answer 23

Produce amylase

Question 24

Why is the stomach a significant part of the digestive system? (3)

Answer 24

• Pummels the food with its muscular wals
• Produces pepsin
• Produces hydrochloric acid to kill bacteria and get the right PH (2)

Question 25

Why is the pancreas a significant part of the digestive system?

Answer 25

- Produces protease, amylase and lipase to be released into the small intestine

Question 26

Why is the small intestine a significant part of the digestive system? (2)

Answer 26

- Produces protease, amylase and lipase to complete digestion - Where digested food is absorbed into the blood

Question 27

Why is the liver a significant part of the digestive system?

Answer 27

Where bile is produced

Question 28

Why is the gall bladder a significant part of the digestive system?

Answer 28

Where bile is stored before it is released into the small intestine

Question 29

Why is the large intestine a significant part of the digestive system?

Answer 29

Where excess water is absorbed

Question 30

Why is the rectum a significant part of the digestive system?

Answer 30

Where faeces is stored before it leaves the body

Question 31

What are the steps food takes from when you eat it to the anus? (9)

Answer 31

- Salivary glands - Oesophagus - Stomach - Liver - Gall bladder - Pancreas - Small intestine - Large intestine - Rectum