2b

Question 1

What is a catalyst?

Answer 1

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

Question 2

Why do enzymes have special shapes?

Answer 2

So they can catalyse reactions

Question 3

What is needed for an enzyme to work?

Answer 3

The substance involved in the reaction has to fit its shape for the reaction to be catalysed

Question 4

At what temperature, in the human body, do enzymes work best?

Answer 4

37 degrees

Question 5

What happens if an enzyme gets too hot?

Answer 5

Bonds holding the enzyme together are broken, so the special shape is destroyed. The enzyme is denatured

Question 6

What pH do enzymes USUALLY work best at?

Answer 6

pH 7

Question 7

What pH do protease enzymes work best at?

Answer 7

pH 2

Question 8

Why does the stomach produce hydrochloric acid?

Answer 8

To kill bacteria and give the right pH for the protease enzyme to work

Question 9

What do digestive enzymes do?

Answer 9

Break down big molecules into small one so they can pass through the walls of the digestive system

Question 10

What enzyme converts starch into sugars?

Answer 10

Amylase

Question 11

Where is amylase made?

Answer 11

1. The salivary glands
2. The pancreas
3. The small intestine

Question 12

What converts proteins into amino acids?

Answer 12

Protease

Question 13

What is protease called in the stomach?

Answer 13

Pepsin

Question 14

Where is protease made?

Answer 14

1. The stomach
2. The pancreas
3. The small intestine

Question 15

What converts lipids into glycerol and fatty acids?

Answer 15

Lipase

Question 16

Where is lipase made?

Answer 16

1. The pancreas

2. The small intestine

Question 17

What does amylase convert?

Answer 17

Starch into sugars

Question 18

What does protease convert?

Answer 18

Proteins into amino acids

Question 19

What does lipase convert?

Answer 19

Lipids into glycerol and fatty acids?

Question 20

Where is bile produced?

Answer 20

The liver

Question 21

Where is bile stored?

Answer 21

The gall bladder

Question 22

Where is bile released?

Answer 22

The small intestine

Question 23

What does bile do?

Answer 23

Neutralises the stomach acid and emulsifies fat

Question 24

Why does bile neutralise the stomach acid?

Answer 24

The hydrochloric acid produced in the stomach makes the pH too acidic for enzymes in the small intestine to work

Question 25

How does bile neutralise stomach acid?

Answer 25

It's alkaline so makes conditions alkaline

Question 26

How does bile emulsify fat?

Answer 26

It breaks fat into tiny droplets

Question 27

Why does bile emulsify fat?

Answer 27

To give a bigger surface area of fat for lipase to work on to speed up digestion

Question 28

What is the function of the salivary glands?

Answer 28

They produce saliva which contains amylase

Question 29

What does the stomach do?

Answer 29

1. Pummels the food with the muscular walls 2. Produces pepsin 3. Produces hydrochloric acid

Question 30

What is the function of the liver?

Answer 30

It produces bile

Question 31

What is the function of the gall bladder?

Answer 31

It stores bile

Question 32

What does the pancreas do?

Answer 32

Produces protease, amylase and lipase. It RELEASES these into the small intestine

Question 33

What does the large intestine do?

Answer 33

It absorbs excess water from food to form faeces

Question 34

What does the small intestine do?

Answer 34

1. Produces protease, lipase and amylase to complete digestion 2. Absorbs digested food into the blood

Question 35

What are enzymes used for?

Answer 35

1. Biological detergents 2. Change foods 3. Industry

Question 36

How are enzymes useful in biological detergents and washing powders?

Answer 36

They work at low temperatures so are cost and energy efficient

Question 37

What enzymes are involved in biological detergents and washing powders?

Answer 37

Proteases and lipases, they digest proteins and fat so remove stains like food and blood

Question 38

How are enzymes used in baby food?

Answer 38

Proteins are pre-digested by proteases which makes it easier for babies to digest food

Question 39

How are enzymes used in foods?

Answer 39

Glucose syrup can be turned into fructose syrup using isomerase enzyme

Question 40

What is an advantage of fructose syrup?

Answer 40

It is sweeter so less is needed, which is good for slimming food as it is less calories

Question 41

How are enzymes useful in industry?

Answer 41

They speed up reactions without the need for high temperatures and pressures

Question 42

What are the advantages of using enzymes in industry?

Answer 42

1. They are specific so only catalyse the reaction if you want them to 2. Lower temperatures and pressures means a lower cost as it saves energy 3. Enzymes work for a long time so after the initial cost of buying them you can continually use them 4. They are biodegradable so cause less pollution

Question 43

What are the disadvantages of using enzymes in industry?

Answer 43

1. Some people can develop allergies to the enzymes 2. Enzymes can be denatured by a small increase in temperature or an increase/decrease in pH so conditions need to be controlled 3. Enzymes can be expensive to produce 4. Contamination of the enzyme with other substances can affect the reaction