Question

Catabolic and anabolic pathways are often coupled in cell because

• A. Both the paths have the same energy
• B. The free energy released from one pathway is used to drive other
• C. The intermediates of a catabolic pathway are used in the anabolic pathway
• D. Their enzymes are controlled by their activators and inhibitors.

Answer 1

The correct option is B The free energy released from one pathway is used to drive other

• Anabolic pathways are those that require energy to synthesize larger molecules. Catabolic pathways are those that generate energy by breaking down larger molecules. Both types of pathways are required for maintaining the cell's energy balance.
  
• Catabolic and anabolic pathway are coupled because catabolic reactions furnish the energy required for anabolism. Catabolic reactions transfer energy from complex molecules to ATP. Anabolic reactions transfer energy from ATP to complex molecules.
• Hence Catabolic and anabolic pathways are often coupled in the cell because the free energy released from one pathway is used to drive other.
• So, the correct answer is 'the free energy released from one pathway is used to drive other'.