NEET PG Medical – 2020 – Question -33
Which amino acid is used to synthesize Nitric oxide?
a) Glycine
b) Arginine
c) Tyrosine
d) Threonine
Show Answer
Correct Answer – B
Ans: B. Arginine
Nitric oxide is formed from arginine by the enzyme nitric oxide synthase (NOS). It contains heme, FAD, FMN, NADPH, and tetrahydrobiopterin.
Nitric oxide has a very short half-life (3-4 seconds). NO combines with oxygen to form NO2. These nitrites are excreted through urine.
Reacting with hemoglobin, NO is converted to NO3; and nitrates are also excreted in the urine. The very low quantity of NO is expelled through the lung.
Arginine is a highly basic, semi-essential amino acid. It is glucogenic in nature.
