Question

The vitamin nicotinamide can be synthesised in our body from
A. Tyrosine
B. Tryptophan
C. Valine
D. Phenylalanine

Answer 1

Hint: Nicotinamide is also known as nicotinic acid amide or niacinamide. It is the active form of vitamin B3 and is soluble in water. Moreover, Nicotinamide also forms an important component of the coenzyme Nicotinamide adenine dinucleotide (NAD).

Complete answer:
Synthesis of nicotinamide can be carried out by the help of amino acid tryptophan. Tryptophan provides base material for the production of nicotinamide or niacinamide. This nicotinamide further forms two coenzymes namely, NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate) having metabolically important roles. This nicotinamide is actually a vitamin. It is also known as vitamin B3. The basic necessary components needed for the production of ATP (adenosine triphosphate) are synthesized with the help of vitamin B3 only. The nutrients and the ATP interconverts energy among themselves with the help of nicotinamide which acts as an electron carrier. Our body can synthesize vitamin B3 therefore it is a non-essential vitamin. In our body, it can be synthesized in the liver with the help of amino acid tryptophan. For production of 1mg of vitamin B3, 60 mg of tryptophan is needed.

So, the correct answer is option “B” , that is the vitamin nicotinamide can be synthesized in our body from tryptophan.

Note: Nicotinamide (also abbreviated as NAM) is another form of soluble vitamin B3. It can be produced by the human body or it can also be taken as a dietary supplement or through medication. It is often used to treat pellagra which is caused by deficiency of niacin. Nicotinic acid or niacin can also be used to treat pellagra but it causes flushing of skin therefore nicotinamide is preferred for its treatment.