Question

1. the nutrient that contains nitrogen is:

○ carbohydrates
○ fats
○ protein
○ water
○ minerals

1. how many amino acids are essential for adults?

○ 7
○ 9
○ 10
○ 22

Explanation:

Question 3

Carbohydrates (formula: $C_n(H_2O)_m$) and fats (lipids, mainly C, H, O) don't have nitrogen. Water is $H_2O$, minerals are inorganic (e.g., Ca, Fe salts) without N. Proteins are made of amino acids, which have the amino group ($-NH_2$) containing nitrogen.

Essential amino acids are those the body can't synthesize and must get from diet. For adults, there are 9 essential amino acids (e.g., histidine, isoleucine, leucine, etc.).

Answer:

Protein

Question 4