The Molecular change in Krebs cycle is __________.
oxaloacetate to oxaloacetate(4C)
oxidation of NADH and FADH2 to build ATP and water molecules
Conversion of pyruvates(3C) to acetyl group (2C)
Conversion of glucose(6C) to 2 pyruvates (3C)
The correct answer is Option 1) oxaloacetate to oxaloacetate (4C).
In the Krebs cycle (also known as the citric acid cycle or TCA cycle), the initial and final molecule is oxaloacetate. Oxaloacetate, which is a 4-carbon molecule, is initially combined with acetyl-CoA (a 2-carbon molecule) to form citrate (a 6-carbon molecule). The subsequent reactions in the cycle involve a series of transformations that ultimately regenerate oxaloacetate.
During these reactions, molecules such as citrate, isocitrate, α-ketoglutarate, succinyl-CoA, succinate, fumarate, and malate are formed and interconverted. However, at the end of the cycle, oxaloacetate is regenerated, allowing the cycle to continue.
Therefore, Option 1) oxaloacetate to oxaloacetate (4C) is the correct answer, as it represents the molecular change that occurs in the Krebs cycle.