B2.3

Question 1

What are protein molecules made up of?

Answer 1

Long chains of small units called amino acids.

Question 2

3 functions of proteins:

Answer 2

• hormones such as insulin
• antibodies which destroy pathogens
• catalysts in the form of enzymes

Question 3

What can you use to speed up reactions?

Answer 3

Use special chemicals known as catalysts.

Question 4

What are chemical reactions controlled by?

Answer 4

Enzymes.

Question 5

What are enzymes?

Answer 5

Special biological catalysts that speed up reactions.

Large protein molecules.

Question 6

What is the active site?

Answer 6

Special shape that allows other molecules to fit into the enzyme protein.

Question 7

What are enzymes involved in?

Answer 7

• building larger molecules from lots of smaller ones
• changing one molecule into another
• breaking down large molecules into smaller ones

Question 8

How do enzymes work?

Answer 8

Substrate of the reaction fits into the active site of the enzyme.
Reaction then takes place rapidly and products are released from the surface of the enzyme.

Question 9

In what temperatures does reactions take place in cells?

Answer 9

Low temperatures.

Question 10

What holds the folded chains in place?

Answer 10

Forces.

Question 11

How does the change in pH affect the forces?

Answer 11

Different enzymes have different pH levels at which they work best in so it will stop them from working completely.

Question 12

What would happen if you didn’t have enzymes?

Answer 12

Reactions in the body wouldn’t happen fast enough to keep you alive.

Question 13

Why is it dangerous when your body temperature gets to 41degrees?

Answer 13

Enzymes start to be denatured and you will soon die.

Question 14

How do the digestive enzymes work differently to other enzymes?

Answer 14

Digestive enzymes work outside the cells.

Question 15

Where are digestive enzymes produced?

Answer 15

By specialised cells in gland and in the lining of your gut.

Question 16

What do digestive enzymes do?

Answer 16

Help break down food into small pieces.

Question 17

What is the name of the enzyme that breaks down starch in your gut?

Answer 17

Carbohydrases.

Question 18

What is the breakdown of protein food catalysed by?

Answer 18

Protease enzymes.

Question 19

Which enzymes break down fats in you gut?

Answer 19

Lipase enzymes.

Question 20

Why do your enzymes almost always have the right temperature to work at their best?

Answer 20

Body makes a variety of different chemical that help to keep conditions ideal for your enzymes all they way through your gut.

Question 21

How does the stomach avoid digesting itself?

Answer 21

Stomach products a thick layer of mucus which coats the stomach walls.

Question 22

Why does the food coming into your small intestine need neutralising?

Answer 22

Provides the ideal conditions for the enzymes in the small intestine.

Question 23

What does bile do?

Answer 23

Emulsified fat droplets to increase the surface area which in turn increases the rate of fat digestion by lipase.

Question 24

What is a biological washing powder? What do they do and contain?

Answer 24

Remove stains and contain proteases and lipases.

Enzymes break down the proteins and fats in the stains.

Question 25

Why does starch need to be converted to sugar before it’s used to make ethanol?

Answer 25

Provides a cheap source of sweetness for food manufactures.

Question 26

What is used to change glucose syrup into fructose syrup?

Answer 26

Isomerase enzyme.

Question 27

2 advantages and disadvantages of using enzymes:

Answer 27

A-can solve industrial problems
A-fairly cheap to run
D-needs expensive equipment
D-requires a lot of energy

Question 28

Pros and cons of biological detergents:

Answer 28

P-very effective
P-less electricity 
P-cheaper for consumer
P-good for environment 
C-trigger allergies
C-bad publicity 
C-low temperatures aren't as good at killing pathogens on clothes
C-worries about enzymes going into rivers etc