Between glycolysis and the citric acid cycle (also known as theKrebs cycle), there are two molecules of ATP and two molecule

ofGTP generated directly. Most of the energy derived from

theoxidation of glucose comes from the oxidation of

FADH2generated from the citric acid cycle.

NADPH generatedfrom the citric acid cycle.

NADH generatedfrom the citric acid cycle.

NADH generatedfrom glycolysis.

The correct answer will be option-NADH generated from the citric acid cycle.

Explanation:

During cellular respiration, few ATP molecules are synthesized by substrate-level phosphorylation in glycolysis and citric acid cycle.

The process also produces high energy equivalents which are NADH and FADH₂ during the citric acid cycle. Two pyruvate molecules generate 6 NADH and FADH₂ molecules. These molecules release electron and hydrogen during the electron transport chain which is utilized to generate the ATP.

Each NADH produces 3 ATP molecule whereas FADH₂ molecule produces 2 ATP molecules. Since 6 NADH (6x3=18 ATP) produced and 2 FADH₂ (2x2).

Thus, NADH provides the highest amount of ATP molecules.