Enzymes - Practice Questions & MCQ

Enzymes are naturally occurring simple or conjugated proteins which act as biological catalysts in living enzymes. Without enzymes, the living process will be too slow to sustain life. Chemically all enzymes are globular proteins. However, some enzymes are also associated with a non-protein component called prosthetic group or co-factor for their activity. 

Properties of Enzymes
Some common properties of enzymes are:

• Specificity: They are highly specific in their action. Each enzyme catalyses only one chemical reaction. For example, the enzyme urease hydrolyse urea to NH₃ and CO₂.
• Efficiency: Enzymes are very efficient catalysts. They can speed up the rate of a reaction by factors of up to 10²⁰.
• Optimum temperature and pH: They are active at moderate temperature and at moderate pH.
• Small quantity: Even a small amount of enzymes can be highly efficient.

Applications of Enzymes:
Enzymes are widely used for:

• In the manufacture of beer and wine by the fermentation of carbohydrates.
• In the production of cheese by coagulation of milk.
• In the manufacture of sweet syrup from corn starch.

Some Enzymes, the substrates on which they act on and the products are summarised below :

• Diastase acts on Starch and converts it into Maltose.
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• Maltase acts on Maltose and converts it into Glucose.
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• Zymase acts on Glucose and converts it into Ethyl alcohol and Carbon dioxide.
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• Invertase acts on Sucrose and converts it into Glucose and Sucrose.
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• Urease acts on Urea and converts it into Ammonia and Carbon Dioxide
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• Pepsin acts on Proteins and converts it into Amino Acids
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