B2.5 Proteins - Their Functions and Uses

Question 1

What are proteins made up?

Answer 1

Long chains of small molecules called amino acids

Question 2

What can proteins act as? (5)

Answer 2

Structural components of tissue, hormones, antibodies and enzymes

Question 3

What is a catalyst?

Answer 3

A substance which increases the speed of a reaction, without being change or used up in the reaction

Question 4

What are enzymes an example of?

Answer 4

A biological catalyst

Question 5

What does an enzyme’s unique shape allow it to do?

Answer 5

Fit onto substances involved in a reaction - this allows the enzyme to work as it helps substances to join together or split apart

Question 6

What happens to enzymes when the temperature is too high?

Answer 6

The bonds holding the enzyme together break, which destroys it’s unique shape - they are now denatured

Question 7

What is the optimum temperature for enzymes to work in the human body?

Answer 7

37°C

Question 8

What happens to enzymes when the pH level they are working in is too high or too low?

Answer 8

The pH interferes with the bonds holding the enzyme together, this changes the shape of the enzyme causing it to denature

Question 9

What is the optimum pH for enzymes to work in?

Answer 9

The optimum pH is different for different enzyme e.g. for Pepsin in the stomach, it’s optimum pH is 2

Question 10

How is food broken down in the digestion system? (2)

Answer 10

By mechanical digestion and chemical digestion

Question 11

What is meant by mechanical digestion?

Answer 11

The breakdown of food through movements like our teeth grinding food down and our stomach churning food

Question 12

What is meant by chemical digestion?

Answer 12

The breakdown of food where enzymes are present to help

Question 13

Where do enzymes work?

Answer 13

Outside body cells

Question 14

Where are enzymes produced?

Answer 14

By specialised cells in glands and in the gut lining

Question 15

How do enzymes help in the digestion of food?

Answer 15

The help to break big molecules of nutrients into smaller molecules so they can easily be absorbed through the walls of the digestive system

Question 16

What is amylase?

Answer 16

A digestive enzyme that catalyses the conversion of starch into sugars

Question 17

Where is amylase made? (3)

Answer 17

In the salivary glands, the pancreas and the small intestine

Question 18

Where does amylase work? (2)

Answer 18

The mouth and the small intestine

Question 19

What are proteases?

Answer 19

Digestive enzymes that catalyse the conversion of proteins into amino acids

Question 20

Where are proteases made? (3)

Answer 20

The stomach, the pancreas, and the small intestine

Question 21

Where do proteases work? (2)

Answer 21

The stomach and small intestine

Question 22

What are lipases?

Answer 22

Digestive enzymes that catalyse the conversion of lipids into glycerol and fatty acids

Question 23

Where are lipases made? (2)

Answer 23

In the pancreas and small intestine

Question 24

Where do lipases work?

Answer 24

The small intestine

Question 25

What is the stomach?

Answer 25

An organ in the digestive system which pummels food with its muscular walls

Question 26

What enzyme does the stomach make?

Answer 26

The protease enzyme, pepsin

Question 27

What acid does the stomach produce?

Answer 27

Hydrochloric acid

Question 28

Why does the stomach produce hydrochloric acid? (2)

Answer 28

To kill bacteria and to give the optimum pH level (pH 2) for the enzymes working in the stomach

Question 29

Where is bile produced?

Answer 29

In the liver

Question 30

Where is bile stored?

Answer 30

The gall bladder

Question 31

Where is bile released?

Answer 31

The small intestine

Question 32

Why is bile released into the small intestine?

Answer 32

Because the enzymes in the small intestine work best in alkaline conditions, but the acid from the stomach makes the small intestine acidic - bile is alkaline and neutralises the HCl making conditions alkaline

Question 33

What affect does bile have on fat?

Answer 33

Bile emulsifies fat - this breaks the fat into tiny droplets which give a bigger surface area for lipase to work on, making digestion faster

Question 34

How can enzymes be harvested?

Answer 34

We can grow microorganisms which produce enzymes which pass out of their cells

Question 35

What’s the difference between biological and non-biological detergents?

Answer 35

Non-bio detergents contain chemicals that break up stains on your clothes, bio detergents contain the same chemical but along with a mixture of enzymes

Question 36

What enzymes do biological detergents contain? (2) Why?

Answer 36

Proteases and lipases, this makes bio detergents ideal for removing stains like food or blood

Question 37

How can bio detergents save you money?

Answer 37

Because they work at lower temperatures which saves money as less energy is used

Question 38

What drawbacks are there to using bio detergents? (3)

Answer 38

They don’t work well at higher temps. because the enzymes denature, they may not work well in very acidic or alkaline tap water, and some of the enzymes can remain on the clothes and can irritate sensitive skin

Question 39

How are enzymes used in the production of baby food?

Answer 39

The proteins are pre-digested by proteases which makes it easier for the baby to digest

Question 40

What happens when carbohydrases is added to starch syrup?

Answer 40

Sugar syrup is made which can be used in food products like sweets, jam and sports drinks

Question 41

How is glucose syrup turned into fructose syrup and why?

Answer 41

It is made by adding isomerase, fructose syrup is sweeter so less can be used, making it ideal for slimming foods

Question 42

What advantages are there to using enzymes in industry? (4)

Answer 42

They’re specific so catalyse the reaction you want them to, they work in lower temperatures and pressures so they save energy and money, they can be re-used and they are biodegradable so they cause less environmental pollution

Question 43

What disadvantages are there to using enzymes in industry? (3)

Answer 43

They can easily be denatured by a slight change in conditions so the conditions they work in must be tightly controlled, enzymes can be expensive to produce and contamination of the enzyme with other substances can affect the reaction