Enzymes

Question 1

To which group of molecules do enzymes belong?

Answer 1

Protein

Question 2

What is an enzyme?

Answer 2

Biological catalyst

Question 3

Where in the cell are enzymes produced

Answer 3

Ribosome

Question 4

What is meant by enzymes enzymes optimum pH

Answer 4

Enzymes working at its best rate at certain pH level

Question 5

What is denatured enzyme

Answer 5

Enzyme has lost its shape can no longer carry out its function

Question 6

Name anabolic process carried out by plants

Answer 6

Photosynthesis

Question 7

Name the factors that influence the activity of an enzyme

Answer 7

1. pH
2. Temperature
3. Enzyme concentration
4. Substarte concentration

Question 8

Name a small molecules which are building blocks for these biomolecules

Answer 8

1. Protein- amino acids

Question 9

Name a difference between catabolic and anabolic

Answer 9

1. Catabolic- respiration (Large molecules break down to form small ones)
2. Anabolic- Photosynthesis (Small molecules form a larger molecule)

Question 10

What is meant by specify of an enzyme?

Answer 10

Only one particular substrate fits the shape of an active site

Question 11

Explain how enzymes work

Answer 11

1. Subsrate combines with active site of enzyme (Active site theory- the active site is complementary shape to substrate)
2. Active site changes shape slightly to better fit the substrate (Induced fit model)
3. Temporary enzyme-substrate complex is produced
4. Substrate changes into the product
5. Products leave active site
6. Active site returns to original shape and can now accept a new substrate

Question 12

State three advantages of using an immobilised enzyme in a bioreactor

Answer 12

1. Easy to recover
2. Easy to re-use
3. Product is pure

Question 13

What is a bioreactor?

Answer 13

vessel used to make a product

Question 14

What is meant by immobilisation?

Answer 14

Enzymes are attached to an inert material

Question 15

Name a substance used to immobilise enzymes

Answer 15

Sodium Alginate

Question 16

Give one application of a named immobilised enzyme. In your answer refer to substrate, enzyme and product

Answer 16

1. Convert Penicillin to different forms to produce new antibiotics

Question 17

Describe how you immobilised an enzyme in the course of practical work

Answer 17

1. Add sodium alginate to 10cm of distilled water (Traps enzyme)
2. In a different beaker add 2g of yeast to water (Yeast contains an enzyme called sucrase)
3. Add the yeast to alginate
4. In a large beaker dissolve 1.5g of calcium chloride into 100cm water (Calcium hardens the beads)
5. Draw 10ml of this yeast-sodium alginate mixture into a syringe and stand over the beaker of Calcium Chloride
6. Mixture will drop in water forming beads
7. Beads are calcium alginate and have yeast trapped/immobilised in them

Question 18

Describe how you examined the application of the immobilised enzyme

Answer 18

1. Add the beads to sucrose
2. Sucrose solution filters down through the beads and drops of glucose are made
3. The drops of glucose are tested using clinistix (Test strips for glucose)

Question 19

Name the enzyme and substrate you used when investigating heat denaturation

Answer 19

Enzyme- Catalase

Substrate- hydrogen peroxide

Question 20

Briefly explain how you carried out the experiment for heat denaturation

Answer 20

1. Add catalase, washing up liquid and pH buffer to a graduated cylinder
2. Add hydrogen peroxide to test tube
3. Stand both in water bath @25C
4. Add hydrogen peroxide to cylinder
5. Note if foam produced
6. Boil catalase for 10 minutes and repeat above steps
7. Result: No activity in boiled catalase as enzyme is denatured

Question 21

Name the enzyme you used when you carried out the experiment into the edict of pH on the rate of enzyme activity

Answer 21

Catalase

Question 22

State the source of enzyme Catalase

Answer 22

Celery

Question 23

State the substrate of this enzyme Catalase

Answer 23

Hydrogen peroxide

Question 24

Explain why the changing pH would have an effect on enzyme activity

Answer 24

Active site is denatured

Question 25

How did you measure the rate of enzyme activity when carrying out the effect of pH

Answer 25

Volume of foam produced per minute

Question 26

What is the chemical nature of enzymes?

Answer 26

Protein

Question 27

What is the molecular shape of an enzyme

Answer 27

Folded

Question 28

Why is it necessary to keep the pH constant in the course of this investigation

Answer 28

to only have one variable

Question 29

How did you keep the pH constant

Answer 29

pH buffer

Question 30

How did you vary temperature in the course of the investigation

Answer 30

Water-bath at different temperatures

Question 31

How did you know the enzyme was working

Answer 31

Foam was produced due to washing up liquid trapping the oxygen

Question 32

What is meant by the term specificity in relation to enzymes?

Answer 32

Only acts on one substrate

Question 33

In each of the following cases state whether the process is anabolic or catabolic

1. Protein synthesis
2. Conversion of ADP to ATP

Answer 33

1. Anabolic

2. Anabolic

Question 34

Apart from C, H, O there is another element always present in enzymes

Answer 34

Nitrogen

Question 35

“Enzymes are essential for metabolism”

Answer 35

Enzymes control metabolic reactions

Question 36

Give one example of the use of immobilised enzymes in bioreactor. In your answer name the enzyme, the substrate and the product

Answer 36

converts penicillin to new antibiotics

penicillin—-(penicillin acylase)—-> New antibiotics