2C Biological enzymes

Question 1

Name the chemical elements found in carbohydrates

Answer 1

Carbon

Hydrogen

Oxygen

Question 2

Name the chemical elements found in proteins

Answer 2

Carbon
Hydrogen
Oxygen
Nitrogen
(sometimes Sulphur)

Question 3

Name the chemical elements found in lipids

Answer 3

Carbon
Hydrogen
Oxygen

Question 4

Proteins are large (macro) molecules made up of…

Answer 4

Amino acids

Question 5

Lipids are large (macro) molecules made up of…

Answer 5

1 Glycerol

3 Fatty acids

Question 6

Carbohydrates are large (macro) molecules made up of …

Answer 6

Simple sugars e.g. glucose

Question 7

Describe how to test for proteins in a sample

Answer 7

Add biuret solution

Sample turns from
blue → purple

Question 8

Describe how to test for starch in a sample

Answer 8

Add iodine solution

Sample turns from
orange → blue/black

Question 9

Describe how to test for glucose in a sample

Answer 9

Add benedict’s solution

Heat to 80-85°C in a water bath

Sample turns from
blue → brick red

Question 10

Describe how to test for lipids in a sample

Answer 10

Sudan III stain solution
If present the solution separates into two. The top layer would be a thin layer of red oil

Question 11

Define the term polymer

Answer 11

Many monomers joined together

Question 12

List all of the main monomers

Answer 12

Glucose

Amino acids

Glycerol

Fatty acids

Question 13

Describe the function of enzymes in our bodies

Answer 13

They act as biological catalysts to speed up reactions

Question 14

Name two factors that affect the rate of enzyme reactions

Answer 14

Temperature

pH

Question 15

What is the area on the enzyme that binds to the substrate called

Answer 15

Active site

Question 16

Define the term substrate

Answer 16

It binds to the active site and gets broken down

Question 17

Describe how temperature affects enzyme activity

Answer 17

Low temperature = substrate and enzymes have less kinetic energy, so less enzyme-substrate complexes form → slow reaction

Too high temperatures = enzyme denatures, substrate cannot bind to active site, no enzyme-substrate complexes form → no reaction

Question 18

Describe how pH affects enzyme activity

Answer 18

Too low or too high pH = enzyme denatures, substrate cannot bind to active site, no enzyme-substrate complexes form → no reaction

Question 19

Describe what denaturing means

Answer 19

The active site changes shape

No longer complementary to the active site

Question 20

Describe the lock and key hypothesis with enzymes

Answer 20

The substrate fits into the active site because it has a complementary shape

Question 21

What is the optimum temperature for enzymes in the human body

Answer 21

37°C