Question

1. what is a common function of carbohydrates, proteins, and fats in the body?

prevent constipation
insulate nerve cells
provide energy
control chemical reactions

Explanation:

• "Prevent constipation" is mainly a function of dietary fiber (a type of carbohydrate but not all carbs, and not proteins/fats), so this is incorrect.
• "Insulate nerve cells" is a function of fats (like myelin), but not a primary common function of all three (carbs, proteins, fats).
• "Provide energy" is a key common function: Carbohydrates are the body's main energy source, fats are a stored energy source, and proteins can be used for energy when needed (though their primary role is structural/enzymatic, etc., energy provision is still a common function among the three).
• "Control chemical reactions" is mainly done by enzymes (proteins) and some other molecules, but carbs and fats don't primarily control chemical reactions. So the correct option is "provide energy".

Answer:

C. provide energy (assuming the options are labeled A, B, C, D with A: prevent constipation, B: insulate nerve cells, C: provide energy, D: control chemical reactions)