Organisation

Question 1

Define enzyme:

Answer 1

Biological catalysts that speed up chemical (metabolic) reactions in the body.

Question 2

What enzyme breaks down proteins?

Answer 2

Protease.

Question 3

Where is protease found/produced?

Answer 3

• The stomach
• The pancreas (in pancreatic fluid)
• The small intestine

Question 4

True or false, enzymes break down large food molecules into smaller food molecules, in order to be absorbed into the bloodstream from the small intestine?

Answer 4

True.

Question 5

What is ‘‘The Lock and Key theory’’?

Answer 5

• Enzymes are specific.
• They have groove on their surface called the active site.
• At the active site, the substrate attaches to it the enzyme and is broken down into a smaller molecule.
• '’The Lock and Key theory’’ theorises that the substrate fits perfectly into it’s specific enzyme in order for it to be broken down.

Question 6

What is a substrate?

Answer 6

The molecule broken down by an enzyme.

Question 7

Proteins are long chains of … ?

Answer 7

Amino acids.

Question 8

What happens when proteins are digested by protease?

Answer 8

• Proteins are long chains of amino acids.
• When we digest protein, protease converts it back into individual amino acids.
• The amino acids are absorbed by body cells and recombine in a different order to make human proteins.

Question 9

How are carbohydrates broken down?

Answer 9

By the enzyme carbohydrase.

Question 10

What are carbohydrates digested to produce?

Answer 10

• Simple sugarse e.g glucose

Question 11

What are proteins digested to produce?

Answer 11

• Amino acids.

Question 12

What are lipids digested to produce?

Answer 12

• glycerol and fatty acids.

Question 13

Starch is a carbohydrate, it consists of a chain of _____ molecules.

Fill in the gap.

Answer 13

Starch is made up of a chain of glucose molecules.

Question 14

Starch is digested by the enzyme … ?

Answer 14

Amylase.

Question 15

Where is carbohydrase/amylase found/produced?

Answer 15

• The saliva
• The pancreas (in pancreatic fluid)

Question 16

1 molecule of lipid is made up of how many molecules of glycerol and fatty acids?

Answer 16

3 molecules of fatty acids and 1 molecule of glycerol.

Question 17

Lipids are digested by what enzyme?

Answer 17

Lipase.

Question 18

Where is lipase found/produced?

Answer 18

• The pancreas (pancreatic fluid)
• The small intestine

Question 19

As well as lipase, the digestion of lipids also involves what?

Answer 19

Bile.

Question 20

Are enzymes proteins?

Answer 20

Yes

Question 21

Is bile a catalyst?

Answer 21

No

Question 22

How does bile aid the digestion of lipids?

Answer 22

• Bile speeds up the digestion of lipids as it emulsifies lipid molecules, to form small droplets.
• This increases the surface area for each molecule to be further broken down by lipase.
• Thus increasing the rate of digestion of lipids.
• Bile is also alkaline.
• Therefore it neutralises the Hydrochloric acid released from the stomach.
• This creates alkaline conditions in the small intestine.
• Thus increasing the rate of digestion of lipids.

Question 23

Where is bile made and stored?

Answer 23

• Made in the liver and stored in the gall bladder.

Question 24

What are the two factors affecting enzyme activity?

Answer 24

• pH and Temperature.

Question 25

Describe what happens to enzyme activity as temperature gradually increases.

Answer 25

• Initially, as temp increases enzyme activity increases.
• This is because the enzyme and substrates start moving faster, so there are more collisions per second between them.
• Then, once enzyme reaches a certain temperature, it starts working at its faster rate and there is a maximum frequency of successful collisions between the substrate and the active site. This temperature is call the optimum temperature.
• Once temp increases past optimum temp, enzyme starts to vibrate and the active site denatures, so the enzyme activity falls rapidly to zero.
• Now it is no longer specific to the substrate, so the enzyme can no longer catalyse it.

Question 26

What is the optimum temperature for enzymes in humans?

Answer 26

37 degrees Celsius.

Question 27

True or false, each enzyme has their own optimum pH?

Answer 27

True.

Question 28

At the optimum pH, what is the activity of the enzyme like?

Answer 28

Enzyme activity is at its maximum.

Question 29

The products of digestion can be used to do what?

Answer 29

• To build new carbohydrates, human proteins and lipids.

Question 30

Carbohydrates are digested to produce?

Answer 30

Simple sugars such as glucose, which can be used for respiration.

Question 31

RP5; Investigation the effect of pH on enzymes, e.g amylase.

Set up an experiment to investigate the effect of pH on enzymes, in this case the enzyme amylase.

You must include the variable, precautions and sources of error and how them.

Question 32

What is a dependent variable?

Question 33

What is an independent variable?

Question 34

What is a control variable?

Question 35

What is the blood up of?

Answer 35

• Plasma
• Red blood cells
• White blood cells
• Platelets

Question 36

What is the plasma and its role?

Question 37

What does the plasma transport?

Question 38

What are red blood cells and their function?

Question 39

State the adaptations of red blood cells:

Question 40

What does haemoglobin in RBCs do?

Question 41

What is a white blood cell and it’s function?

Question 42

True or false, white blood cells are part fo the immune system?

Question 43

What do we used to test for Lipids and what is the positive result?

Question 44

What is used to test for starch and what is the positive result?

Question 45

What is used to test for carbohydrate and what is the positive result?

Question 46

What is used to test for proteins and what is the positive result?

Question 47

what is starch made from?

Answer 47

maltose.