Unit 2 - Proteins

Question 1

What are proteins?

Answer 1

Proteins are the major structural materials of animal tissue and are also involved in the maintenance and regulation of life processes.

Question 2

Could we survive without proteins?

Answer 2

No

Question 3

What are proteins made from?

Answer 3

Amino Acids

Question 4

What do we call amino acids that we cannot make naturally in the body?

Answer 4

Essential Amino Acids

Question 5

What are enzymes?

Answer 5

Enzymes are proteins which act as biological catalysts.

Question 6

What do proteins contribute to in our body?

Answer 6

Growth and repair

Question 7

What happens when we take a protein and heat it with soda lime and what does this show?

Answer 7

A pungent alkaline smell is given off. This shows the gases are all amines or ammonia. This suggests that the proteins contain nitrogen

Question 8

What 2 functional groups do amino acids contain?

Answer 8

A carboxyl (COOH) group and an amine (NH2) group

Question 9

What is the link called from the condensation reaction of amino acids?

Answer 9

An amide (O=C-NH) link

Question 10

What is another (more biological) name for an amide link?

Answer 10

A peptide

Question 11

In an amide link how many hydrogens are bonded to the N atom?

Answer 11

1

Question 12

Asparagus has flavour molecules which are soluble in water. Would you cook it in oil or water?

Answer 12

Oil - cooking in water removes flavour molecules from asparagus

Question 13

What is volatility a measure of?

Answer 13

How easily something will evaporate

Question 14

Are amide links polar?

Answer 14

Yes - N-H bond is polar and can also hydrogen bond

Question 15

What are the 2 types of proteins?

Answer 15

Fibrous and globular

Question 16

What are fibrous proteins?

Answer 16

The main structural material in animal tissue

Question 17

What are globular proteins?

Answer 17

Globular proteins are involved in the maintenance and regulation of life processes.

Question 18

What types of proteins do enzymes contain?

Answer 18

Globular

Question 19

Why can an enzyme only catalyse a specific reaction?

Answer 19

They are shape specific and will only work with specific protein shapes (The lock and key principal)

Question 20

What happens when proteins are heated and what is this called?

Answer 20

H-bonds will break and protein loses it’s 3D structure.
This is called denaturing

Question 21

What does the denaturing of proteins in food cause?

Answer 21

A change in texture

Question 22

When food is spoiled what is said to have happened?

Answer 22

It has oxidised

Question 23

Broccoli contains flavour molecules which are oil soluble. What should you cook it in?

Answer 23

Water. Oil would dissolve and remove flavour from the food