Question

multiple choice question

which of the following metabolic pathways begins with glucose and yields two pyruvates?

ets
glycolysis
transition reaction
krebs cycle
beta oxidation

Explanation:

Identify the starting reactant and final products

The question asks for a metabolic pathway that starts with one molecule of glucose (a 6-carbon sugar) and ends with two molecules of pyruvate (a 3-carbon compound).

Evaluate the given options

• ETS (Electron Transport System): Uses high-energy electrons from NADH and \(FADH_2\) to generate a proton gradient for ATP synthesis; it does not break down glucose to pyruvate.
• Glycolysis: The enzymatic pathway that converts glucose (\(C_6H_{12}O_6\)) into two molecules of pyruvate (\(C_3H_4O_3\)).
• Transition reaction: Converts pyruvate into acetyl-CoA; it begins with pyruvate, not glucose.
• Krebs cycle: Oxidizes acetyl-CoA to \(CO_2\); it does not begin with glucose.
• Beta oxidation: Breaks down fatty acids into acetyl-CoA; it does not involve glucose.

Answer:

• ETS
• Glycolysis (Correct answer)
• Transition reaction
• Krebs cycle
• Beta oxidation