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[Biology Form 4] Enzyme

1. Structure: What chemical compound is an enzyme made up of? 
Proteins.                                           

2. Function: What is the role played by enzymes in living organisms?
Enzymes speed up the rate of chemical reactions in living organisms.

3. State the characteristics of enzymes:
a) Enzymes are made up of proteins.
b) They are catalysts that speed up the rate of a reaction.

c) They are not destroyed / altered by the reactions they catalyse.

d) Enzymes have specific active sites where they bind with substrates.

e) Enzymes show substrate specificity - they can only bind with specific substrates.

f) Enzymes are needed only in small amounts.

g) Enzyme-catalysed reactions are reversible - they catalyse reactions in either direction.

h) The activity of enzymes can be slowed down by inhibitors.

i) Enzymes work more effectively with the help of co-factors.

j) Enzymes are affected by factors such as temperaturepHsubstrate concentration and enzyme concentration.


4. Define enzyme
An enzyme is a biological catalyst that speeds up the rate of chemical reactions occurring in living organisms.

5. Where are enzymes synthesised in a cell?
In ribosomes.

6. Where are enzymes modified and packaged in a cell?
In the Golgy body.

7. Example: State an example of enzymes involved in the digestion or hydrolysis of each of the following substrates:
a) StarchAmylase
b) ProteinsPepsin
c) FatsLipase
d) MaltoseMaltase
e) LactoseLactase
f) SucroseSucrase
g) CelluloseCellulase


8. Effect: What would be the effect on digestion if enzymes were unavailable?
Digestion would be slowed down drastically.

9. State four factors that affect enzyme activity.
Temperature, pH, enzyme concentration and substrate concentration.

10. Sketch a graph for each of the factors on enzyme activity. Label the x-axis and y-axis correctly.