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Question 1

What do enzymes do?

Answer 1

Control the speed of almost all chemical reactions in our bodies, mostly in the cytoplasm of our cells
It acts as a biological catalyst

Question 2

What do digestive enzymes do?

Answer 2

Break down large, insoluble molecules into smaller, soluble ones that can be absorbed

Question 3

How ads molecules absorbed during the digestive system?

Answer 3

They’re absorbed into the blood through the walls of the small intestine

Question 4

Explain how enzymes work?

Answer 4

• a type of protein, protein is formed of a,ink acids which fold and coil into shapes
• enzymes fold into a shape which has an indentation called active site
• which allows a substrate to fit into it as they’re complementary

Question 5

When an active site fits with a substrate what’s it called?and what have they formed?

Answer 5

Complementary

And form enzyme-substrate complex

Question 6

How do enzymes work?

Answer 6

-By lowering the activation energy, which is needed for a reaction to begin

Question 7

What do carbohydrate do?

Answer 7

Break down large carbohydrates into smaller sugars

Question 8

What do protease do?

Answer 8

Break down protein into amino acids

Question 9

What sort of enzyme is amylase?

Answer 9

A carbohydrase

Question 10

Why does enzyme activity increase as the temperature rises?

Answer 10

• the substrate molecules have more kinetic energy

- the frequency of enzyme-substrate collisions increases

Question 11

Where is protease produced?

Answer 11

Stomach, pancreas and small intestine

Question 12

Where does amylase break down starch into glucose?

Answer 12

Mouth abs small intestine

Question 13

Where is protein made?

Answer 13

In cell ribosomes

Question 14

What does lipase do?

Answer 14

It breaks down lipids into (fats and oils) into fatty acids and glycerol

Question 15

Where is lipase produced?

Answer 15

In the pancreas and small intestine

Question 16

Why is the shape of an enzyme so important?

Answer 16

• the shape of the active site is important because it fits with 1 particular substrate, meaning each enzyme can only catalyse 1 reaction
• it also means that any condition that changes the shape of the active site can prevent the enzyme from working

Question 17

What 2 things affect the shape of the active site?

Answer 17

Temperature and pH

Question 18

Explain why increasing the temperature affects the shape of the active site?

Answer 18

• increasing the temperature gives molecules more kinetic energy, which increases the rate of collisions & allows the reaction to happen faster
• but if the temperature is too high, it damages the shape of the active site this is called denaturing, which stops the reaction
• a denatured enzyme is permanent?

Question 19

Explain why changing the pH affects the shape of the active site?

Answer 19

• each enzyme has an optimum pH at which it operates
• if the solution becomes too acidic or alkaline the H+ or OH- ions change the forces that hold the active site in its specific shape
• which prevents the substrate from binding, slowing the reaction until the enzyme is denatured

Question 20

Why can’t we digest fibres?

Answer 20

Because we don’t have the right enzymes

Question 21

Why does bile emulsify fat?

Answer 21

To increase the surface area so enzymes work faster

Question 22

What are enzymes made of?

Answer 22

Proteins and amino acids

Question 23

What’s lost when an enzyme is denatured?

Answer 23

The shape of the active site

Question 24

Name 2 processes catalysed by enzymes?

Answer 24

Photosynthesis and digestion

Question 25

Give 2 reasons why starch isn’t digested in the stomach

Answer 25

• the stomach does make amylase

- the pH of the stomach is too low and could denature the amylase

Question 26

Define fermentation

Answer 26

The conversion of sugar into acids occurs in yeast

Question 27

What’s the use if bile in the digestive system?

Answer 27

• made in the liver stored in the gall bladder
• it’s alkaline to neutralise the hydrochloric acid from the stomach
• emulsifies fat into small pieces to increase its surface area
• the alkaline And large surface area increases the rate of fat breakdown by lipase