Based on the diagram below, which of the following statements is correct?

• A. Once amino acids are absorbed, they are first built up into proteins, then relocated throughout the body.
• B. Amino acids are absorbed by the small intestine, then deaminated before entering the amino acid pool.
• C. All protein that is deaminated will be excreted in urine.
• D. While most of the amino acids absorbed by the body are used to make protein some are used to make non-protein products such as glucose, fat, & some nitrogen-containing molecules.

Answer: (D)

Verified step by step guidance

1. Examine the diagram provided. It illustrates the process of protein metabolism, starting with dietary protein being broken down into amino acids, which enter the amino acid pool.
2. Understand the role of the amino acid pool. Amino acids in this pool can be used for protein turnover, where they are either built into proteins (e.g., enzymes) or broken down again.
3. Note that some amino acids are used to create non-protein, nitrogen-containing products, such as hormones, as indicated in the diagram.
4. Observe the deamination process. Amino acids that are not used for protein synthesis or non-protein products undergo deamination, where the amine group is removed.
5. Follow the pathway after deamination. The amine groups are converted into urea, which is then excreted via urine, as shown in the diagram.