in what chemical form is glucose when it enters the Krebs Cycle?

Glucose enters the Krebs Cycle, also known as the citric acid cycle or the tricarboxylic acid (TCA) cycle, through a series of conversions. Initially, glucose is converted into pyruvate in a process called glycolysis, which takes place in the cytoplasm of cells.

During glycolysis, glucose is broken down into two molecules of pyruvate, generating a small amount of ATP and NADH (nicotinamide adenine dinucleotide). Next, pyruvate undergoes a chemical transformation known as pyruvate decarboxylation, converting each pyruvate molecule into acetyl CoA. This decarboxylation step occurs in the mitochondria.

So, to answer your question, glucose is not directly involved in the Krebs Cycle. Instead, it is converted into acetyl CoA, which enters the Krebs Cycle to produce energy in the form of ATP.