Question

Which of the following contains nitrogen?
(A) Fats
(B) Proteins
(C) Carbohydrates
(D) All of the above

Answer 1

Hint: Nitrogen occurs in all organisms, primarily in amino acids, in nucleic acids and in the energy transfer molecule adenosine triphosphate. The human body contains about $3\%$ nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen.

Complete step by step solution:
In addition to carbon, hydrogen and oxygen atoms, all proteins contain nitrogen.
Proteins are large biological molecules or macromolecules consisting of one or more long chains of amino acids and carboxylic acid.
Therefore, proteins are macromolecules formed by amino acids. There are a total of 20 different amino acids in proteins and hundreds and thousands of these amino acids are attached to each other in long chains to form proteins.
Our body uses proteins to build and repair tissues. It also uses proteins to make enzymes, hormones, and other body chemicals. Protein is an important building lock of bones, muscles, skin and blood.
There are two main categories of proteins- animal and plant based protein.
Animal proteins include:
- Egg
- Chicken
- Whey(dairy)
- Casein(dairy)
- Beef
Plant based protein include:
- Pea
- Brown rice
- Soya bean
- Chickpea
The main difference between animal and plant based protein is their amino acid profile. Most animal proteins are complete protein, which means that they contain all essential amino acids.
Whereas, most plant proteins are considered incomplete proteins, which means that they are missing at least one essential amino acid.
However, eating multiple plant proteins together can create the effect of complete proteins.

Hence, option B is correct.

Note: Beginning around the age of 40, a person begins to lose up to $3 - 5\% $ of muscle mass per decade, a condition known as Sarcopenia. This is the reason why falls and fractures are so common among the elderly. Hence, increasing the protein intake can help in preserving the muscles and fight off Sarcopenia.