Proteins and Enzymes

Question 0

Give some examples of the functions of proteins (3 marks)

Answer 0

Structural ( like muscles) Hormones ( like insulin) Antibodies Enzymes ( biological catalysts)

Question 1

What is a protein? ( 3 marks)

Answer 1

A larger biological molecule made up from amino acids. These fold into unique shapes that other molecules can fit into allowing proteins to do their jobs

Question 2

What is a biological catalyst?

Answer 2

Speeds up a reaction inside a living thing

Question 3

Are all proteins enzymes?

Answer 3

No, but all enzymes are proteins

Question 4

What is the active site?

Answer 4

The part of the enzyme which is complimentary to the substrate( ie they fit together)

Question 5

At what temperature do most human enzymes work at?

Answer 5

37 oC

Question 6

When an enzyme gets too hot and changes shape, what do we say has happened?

Answer 6

The enzyme has denatured

Question 7

Is it only temperature which denatures enzymes?

Answer 7

No, extremes of pH can also denature enzymes

Question 8

True or false All enzymes work best at pH 7

Answer 8

False In the stomach, protease enzymes prefer pH 2 as their optimum condition

Question 9

Give 2 examples of mechanical digestion

Answer 9

Chewing and stomach churning

Question 10

Which enzyme breaks down starch?

Answer 10

Amylase (carbohydrase)

Question 11

Glycerol and fatty acids are the product, what is the catalyst?

Answer 11

Lipase enzymes

Question 12

What is the only type of food digested in the stomach?

Answer 12

Protein

Question 13

What is bile and where is it made and stored? What does it do? ( 4 marks)

Answer 13

Made in the liver Stored in the gall bladder Neutralises stomach contents Emulsifies fats

Question 14

What enzymes are in washing powders?

Answer 14

Proteases and lipases

Question 15

Why don’t washing powders work in very hot water?

Answer 15

The enzymes are denatured

Question 16

Which enzymes are found in baby foods?

Answer 16

Protease enzymes pre- digest hard to digest proteins

Question 17

Which enzyme is found in slimming foods and how does it work? (3 marks)

Answer 17

Isomerase Converts glucose to fructose Fructose is sweeter so you need less

Question 18

Which enzyme digests starch syrup?

Answer 18

Carbohydrase converts starch syrup into sugar syrup

Question 19

What are enzymes?

Answer 19

Biological catalysts

Speed up rate of reaction

Proteins Made of amino acids folded into a specific shape

An enzyme is specific to the substrate

Question 20

What has happened to this enzyme?

Answer 20

It has been denatured by high temperatures or extremes of pH

Question 21

Where would we find enzyme X working in the human body?

Answer 21

In the stomach ,as it is the only place which is pH 2