Assimilation uses absorbed nutrients to build or store body components

Steps:

• Define assimilation: process after absorption where simple food molecules are used to synthesize complex body molecules or energy stores.
• Examine option A: amino acids (absorbed) build antibodies (body proteins)—fits assimilation.
• Examine options B and C: fatty acids form lipids and glucose forms glycogen—both use absorbed molecules for synthesis/storage, fitting assimilation.
• Examine option D: proteins to amino acids describes breakdown (digestion), not using absorbed molecules for building.

Why D is correct:

• Assimilation requires prior absorption of simple molecules (like amino acids); converting proteins to amino acids is hydrolysis in digestion, preceding absorption.

Why the others are wrong:

• A: Antibodies are synthesized from absorbed amino acids, exemplifying assimilation.
• B: Lipids are built from absorbed fatty acids, a clear assimilation process.
• C: Glycogen storage from absorbed glucose is energy assimilation.

Final answer: D