Answer:
two turns
Explanation: At the end of glycolytic pathway, One glucose molecule produces two Acetyl-CoA molecules, the energy output of the Kreb's cycle is usually expressed as the product of the two cycles needed to break down both Acetyl-CoA's.
Steps in the Krebs Cycle
The Krebs Cycle releases energy from acetyl–CoA, but the cellular task is to release energy in a steady and useful way. Thus, the pathway (1) links the acetyl group(2-carbon) of Acetyl-CoA to the substrate(4-carbon) to create a 6-carbon molecule;
(2) rearranges the 6-carbon molecule to a more reactive form;
(3) removes one of the carbon molecules of the substrate to form a 5-carbon molecule and releases energy;
(4) removes another of the carbon atoms of the substrate to form a 4-carbon molecule and releases energy; and
(5) rearranges energy; The main point is that the substratum is first extracted and its carbon atoms emitted in the form of CO2, and only then are the atoms rearranged to reconstruct the substratum in the acetate (from the Acetyl–CoA).