Question

multiple choice question

at the end of glycolysis, the carbons from glucose are now located in:

two g3p molecules.
two pyruvic acids.
atp.
\\(\text{co}_2\\).

Explanation:

Identify the starting reactant and end products of glycolysis

Glucose, a 6-carbon sugar, is broken down during glycolysis.

Track the carbon atoms through the pathway

One 6-carbon glucose molecule is cleaved into two 3-carbon glyceraldehyde 3-phosphate (G3P) molecules during the energy investment phase, which are then converted into two 3-carbon pyruvic acid (pyruvate) molecules by the end of the energy payoff phase.

Evaluate the given options

• "two G3P molecules": G3P is an intermediate, not the final product.
• "two pyruvic acids": Correct, as these are the final carbon-containing products of glycolysis.
• "ATP": ATP contains carbon in its adenosine group, but these carbons do not originate from the glucose substrate.
• "CO2": Carbon dioxide is not released during glycolysis; it is released in later stages (pyruvate oxidation and the Krebs cycle).

Answer:

• two G3P molecules.
• two pyruvic acids. (Correct answer)
• ATP.
• \(\text{CO}_2\).