Question

Number of carbon atoms present citric acid, oxaloacetic acid and pyruvic acid are
A) 6, 3 and 3 respectively
B) 6,4 and 3 respectively
C)5, 4 and 3 respectively
D) 6, 4 and 2 respectively

Answer 1

Hint:Since radioactive pollutant is taken up into bone, the bone itself and nearby soft tissues may be damaged by radiation released over time.

Complete answer:
Citric acid is a weak organic acid with the formula \[{{\text{C}}_{\text{6}}}{{\text{H}}_{\text{8}}}{{\text{O}}_{\text{7}}}\]. They occur naturally in citrus fruits like oranges, lemons etc. Citric acid is used as an intermediate in the biochemical cycle called the Krebs cycle or the citric acid cycle.
Citrate is an intermediate biochemical in the TCA cycle (Tricarboxylic acid cycle, or Krebs cycle), a central metabolic pathway for animals, plants, and bacteria under aerobic conditions. Citrate synthase is an enzyme that catalyzes the condensation of oxaloacetate with acetyl CoA to form citrate. Citrate then acts as the substrate for aconitase and is converted into aconitic acid. The cycle ends with regeneration of oxaloacetate.
Citric acid is hence a 6-C compound.
Pyruvic acid (\[\text{C}{{\text{H}}_{\text{3}}}\text{COCOOH}\]) is the simplest form of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate is the conjugate base \[\text{C}{{\text{H}}_{\text{3}}}\text{COCO}{{\text{O}}^{-}}\], which is a key intermediate in several metabolic pathways throughout the cell.
Oxaloacetic acid is a crystalline organic compound with the chemical formula \[\text{H}{{\text{O}}_{\text{2}}}\text{CC}\left( \text{O} \right)\text{C}{{\text{H}}_{\text{2}}}\text{C}{{\text{O}}_{\text{2}}}\text{H}\].
Oxaloacetic acid, in the form of its conjugate base oxaloacetate, is a metabolic intermediate in many processes that occur in animals. It takes part in gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, fatty acid synthesis and the citric acid cycle.
Oxaloacetate is an intermediate of the citric acid cycle, where it reacts with acetyl-CoA to form citrate, catalyzed by the enzyme citrate synthase. It is also involved in biogeochemical cycles like gluconeogenesis, the urea cycle, the glyoxylate cycle, amino acid synthesis, and fatty acid synthesis.
Oxaloacetic acid is a 4-C compound.
Pyruvic acid can be made from glucose through glycolysis where glucose a 6-C compound breaks down to form 2 molecules of 3-C pyruvic acid and again converted back to a carbohydrate through gluconeogenesis. It can also be converted to fatty acids in the acetyl CoA cycle. It is used to develop alanine, ethanol or lactic acid via fermentation.
Pyruvic acid supplies energy to cells through the citric acid cycle also known as the Krebs cycle under aerobic conditions of respiration and alternatively ferments to produce lactate during anaerobic respiration or lactic acid cycle.
Hence the correct answer is (B.)

Note:The release of carbon dioxide is coupled with the reduction of NAD+ to NADH in the citric acid cycle. Acetyl CoA transfers its acetyl group to oxaloacetate to form citrate and begin the citric acid cycle. TCA is the alternative name for the Krebs cycle or citric acid cycle.