LIFE SCIENCE

Detailed explanation-1: -Nucleic acids contain the same elements as proteins: carbon, hydrogen, oxygen, nitrogen; plus phosphorous (C, H, O, N, and P). Nucleic acids are very large macromolecules composed of repetitive units of the same building blocks, nucleotides, similar to a pearl necklace made of many pearls.

Detailed explanation-2: -Carbohydrates and lipids are made of carbon, hydrogen, and oxygen (CHO). Proteins are made of carbon, hydrogen, oxygen, nitrogen, & sometimes sulfur (CHONS). Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, and phosphorus (CHONP).

Detailed explanation-3: -A: All biochemical compounds contain carbon, hydrogen, and oxygen; and proteins as well as nucleic acids contain nitrogen. Phosphorus is the only element that is identified with nucleic acids.

Detailed explanation-4: -Proteins contain the elements carbon, hydrogen, and oxygen just as carbohydrates and lipids do, but proteins are the only macronutrient that contains nitrogen.

Detailed explanation-5: -Therefore, nitrogen is the element that is only present in proteins but not in lipids or carbohydrates.