Which of the following is an anabolic process

Step 1: Analyze the question We need to identify which process is anabolic.

Step 2: Explain the concept Metabolism has two parts:

• Anabolism is the building up of complex molecules from simpler ones. It requires energy. Example: photosynthesis, protein synthesis.
• Catabolism is the breakdown of complex molecules into simpler ones. It releases energy. Example: respiration, digestion, fermentation.

Step 3: Go through the options

• A. Excretion: This is the removal of metabolic waste from the body. It is not a building-up process.
• B. Fermentation: This is the incomplete breakdown of glucose (to alcohol or lactic acid) without oxygen. It is catabolic.
• C. Photolysis: This is the splitting of water using light energy in the light stage of photosynthesis. It is a breakdown step, so it is not anabolic by itself.
• D. Photosynthesis: Simple molecules (CO₂ and water) are built up into a complex molecule (glucose) using light energy.

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ (in light, with chlorophyll)

This is a clear case of anabolism.

• E. Transportation: This is the movement of substances in the organism. It is not a metabolic building process.

Step 4: Answer The correct option is **D.

Exam tip: Remember "Anabolism = Assemble". Anything that builds a bigger molecule from smaller ones, such as photosynthesis or protein synthesis, is anabolic. Anything that breaks molecules down, such as respiration, digestion, or fermentation, is catabolic.