Metabolism and Enzymes

Free sample questions

Metabolism and Enzymes — sample Biology questions with answers

1. Question 1

   The metabolic process that involves the breakdown of complex molecules into simpler molecules is known as...

   • AAnabolism
   • BCatabolism
   • CPhosphorylation
   • DCondensation

   Answer: B. Catabolism

   Catabolism is the process of breaking down complex molecules into simple ones, releasing energy, e.g. cellular respiration.

2. Question 2

   The main compound that forms the structure of enzymes is...

   • ALipid
   • BProtein
   • CCarbohydrate
   • DNucleic acid

   Answer: B. Protein

   Enzymes are globular proteins that act as biological catalysts in cellular reactions.

3. Question 3

   The optimum temperature for most enzymes in the human body is...

   • A$27^{\circ }\text{C}$
   • B$37^{\circ }\text{C}$
   • C$45^{\circ }\text{C}$
   • D$60^{\circ }\text{C}$

   Answer: B. $37^{\circ}\text{C}$

   The optimum human body temperature for most enzymes is $37^{\circ }\text{C}$.

4. Question 4

   The enzyme pepsin in gastric juice functions most optimally at...

   • ApH $2$
   • BpH $7$
   • CpH $8$
   • DpH $10$

   Answer: A. pH $2$

   Pepsin acts in the acidic environment of the stomach with an optimum pH of around $2$.

5. Question 5

   The main function of enzymes in biochemical reactions is to...

   • AIncrease the activation energy
   • BLower the activation energy
   • CChange the equilibrium of the reaction
   • DIncrease the temperature of the reaction

   Answer: B. Lower the activation energy

   Enzymes lower the activation energy so that reactions occur faster at body temperature.