Question

Which of the following is not a function of amino acids (from protein digestion) in the body?

• A. Energy production
• B. Regulation of body processes
• C. Growth of body tissues
• D. Maintenance and repair of body tissues

Hint:

Think of proteins as the "building materials" of a house and carbs/fats as the "fuel" for the heaters. You only burn the wooden furniture (proteins) if you run out of coal/gas (carbs/fats).

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks to identify which of the listed biological functions is not a primary or "regular" role of amino acids derived from dietary proteins in a healthy, well-nourished body.

Step 2: Detailed Explanation:

• Primary Functions (B, C, D): The main purpose of amino acids is to serve as building blocks. They are used for the growth of new tissues, the maintenance and repair of existing tissues, and the synthesis of enzymes, hormones, and antibodies that regulate body processes.

• Energy Production (A): While the body can use amino acids for energy (providing approximately 4 kcal/g), it is not their "intended" or primary function. The body preferentially uses carbohydrates and fats for energy. Using protein for energy (via gluconeogenesis or direct oxidation of carbon skeletons) typically only occurs during starvation, prolonged intense exercise, or when protein intake greatly exceeds the body's structural needs. This process involves the removal of the nitrogen group (deamination), which puts stress on the kidneys.

• Context of "Not a function": In nutritional studies, protein is considered a structural and functional nutrient rather than a fuel nutrient. Thus, in the context of physiological priorities, energy production is considered the exception rather than the rule for amino acids.

Step 3: Final Answer:
The primary physiological role of amino acids is structural and regulatory. Using them for energy is a secondary, less efficient pathway. Option (A) is the correct choice here.