Question

Glycolysis consists of

• A. ten enzymatic reactions that convert a six-carbon molecule to four-carbon pyruvate and result in a net : gain of 4 ATP molecules
• B. eight enzymatic reactions that convert a six-carbon molecule to four-carbon pyruvate and result in a net gain of 4 ATP molecules
• C. ten enzymatic reactions that convert a six-carbon molecules to three-carbon pyruvate and result in a net gain of 2 ATP molecules
• D. eight enzymatic reactions that convert a six-carbon molecules to three-carbon pyruvate and result in a net gain of 2 ATP molecules

Answer 1

Answer: (C)

Glycolysis (Embeden Meyerhof Paranas pathway)is the sequence of ten enzyme catalysed reactions that converts glucose into two molecules of pyruvate, plus two molecules of NADH with concomitant formation of two ATP molecules. It occurs in the cell cytoplasm. The overall reaction of glycolysis can be summarised as follows -
$\underset{\text{Glucose }}{C _{6} H _{12} O _{6}}+2 NAD +2 ADP +\underset{\text{inorganic phosphate}}{2 pi} \longrightarrow \underset{\text{Pyruvic acid}}{ CH _{3} COCOOH +2 NADH _{2}}+2 ATP$
Thus, for each molecule of glucose metabolised by glycolysis there is a net yield of two ATP molecules.