Proteins, catalysts and enzymes

Question 1

What are proteins molecules made of?

Answer 1

Long chains of amino acids.

Question 2

Long chains of amino acids that make up proteins are folded to produce specific shapes, on what does the shape of a protein depend?

Answer 2

Its function.

Question 3

What four things can proteins be?

Answer 3

1) Structural components of tissues, such as muscle.
2) Hormones
3) Antibodies
4) Catalysts

Question 4

What controls chemical reactions in cells?

Answer 4

Proteins called enzymes.

Question 5

What are enzymes?

Answer 5

They are large proteins that speed up reactions in the body, biological catalysts.

Question 6

The shape of an enzyme has a special area for what and what is this called?

Answer 6

An enzyme has a special area where other molecules can fit called the active site.

Question 7

What happens to the substrate in a reaction?

Answer 7

The substrate can be held in the active site, and either be connected to another molecule or be broken down.

Question 8

What three things can enzymes do in the body? Give examples of each.

Answer 8

1) Build large molecules from many smaller ones, e.g. building starch from glucose molecules.
2) They can change one molecule into another, e.g. convert one type of sugar into another.
3) They can break down large molecules into smaller ones, e.g. all the digestive enzymes do this.

Question 9

What happens to an enzyme if the temperature get too hot?

Answer 9

The enzyme stops working because the active site changes shape, we say the enzyme has been denatured.

Question 10

What happens if the pH becomes to acidic or too alkaline for a particular enzyme and why?

Answer 10

If the pH becomes to acidic or too alkaline for a particular enzyme then the enzyme will be denatured because certain enzymes work best at different pH values.

Question 11

What is digestion?

Answer 11

Digestion involves breaking down large insoluble molecules down into smaller soluble molecules.

Question 12

Where is amylase produced, what does it catalyse the digestion of and where?

Answer 12

Amylase is produced in the salivary glands, small intestine and pancreas and catalyses the digestion of starch into sugars in the mouth and small intestine.

Question 13

Where is protease produced, what does it catalyse the digestion of and where?

Answer 13

Protease is produced by the stomach, the pancreas and the small intestine and catalyses the digestion of proteins into amino acids in the stomach and small intestine.

Question 14

Where is lipase produced, what does it catalyse the digestion of?

Answer 14

Lipase is produced by the pancreas and small intestine and catalyses the digestion of lipids into fatty acids and glycerol.

Question 15

Protease enzymes work best in what conditions? What creates these conditions in the stomach?

Answer 15

Proteases work best in acidic conditions, glands in the stomach wall produce hydrochloric acid to create very acidic conditions.

Question 16

Amylase and lipase work where and in what conditions do they work best?

Answer 16

Amylase and lipase work in the small intestine, they work best when the conditions are slightly alkaline.

Question 17

What does the liver produce and where is it stored?
What does this substance do?
How does this affect the conditions in the small intestine?

Answer 17

The liver produces bile which is stored in the gall bladder, the alkaline bile is squirted into the small intestine and neutralises stomach acid.
Bile makes the conditions in the small intestine slightly alkaline.

Question 18

What are biological detergents?

What are the two main advantages of biological detergents?

Answer 18

Biological detergents contain proteases and lipases that digest food stains.
They work at lower temperatures than ordinary washing powder which saves energy and money spent on electricity.

Question 19

What are proteases used for?

Answer 19

Proteases are used to pre-digest proteins in some baby foods.

Question 20

What is isomerase used for?

What are the benefits of this?

Answer 20

Isomerase are used to convert glucose syrup into fructose syrup.
Fructose is much sweeter so less is needed in foods, which makes foods less fattening.

Question 21

What are carbohydrases used for?

Answer 21

Carbohydrases are used to convert starch into sugar syrup for use in foods.

Question 22

What are enzymes used for in industry?

Why is this important?

Answer 22

In industry enzymes are used to bring about reactions at normal temperatures and pressures.
It saves a lot of money on expensive equipment and energy.

Question 23

Give four advantages and five disadvantages of using enzymes.

Answer 23

Advantages:

1) They are very effective at removing stains such as blood, grass and gravy in biological washing powders.
2) Biological washing powder can be used at lower temperatures, which saves energy and reduces cost.
3) Some enzymes are used in medicine to diagnose, control or even cure disease.
4) They can reduce costs of energy and equipment in industry.

Disadvantages:

1) If people misuse washing powders they may have allergic reactions on their skin.
2) Enzymes may enter waterways via the sewage system.
3) Industrial enzymes can be costly to produce.
4) Enzymes can denature at the high temperatures needed to kill pathogens in the washing.
5) Some fabrics such as wool will be digested by proteases.