Amino acid uptake and utilization in the body

Steps:

• Proteins are digested into amino acids in the stomach and small intestine.
• Amino acids are absorbed across the intestinal wall into the bloodstream (process P).
• Absorbed amino acids are transported to cells for use in protein synthesis or energy (process Q).
• Thus, P and Q represent absorption followed by assimilation.

Why A is correct:

• Absorption is the transport of amino acids from the gut lumen into blood; assimilation is their incorporation into body tissues, matching the sequence for nutrient processing.

Why the others are wrong:

• B: Digestion precedes absorption, so absorption cannot follow digestion here.
• C: Places absorption before digestion, reversing the biological order.
• D: Assimilation occurs after absorption, not digestion.

Final answer: A