In the lab, glucose can be oxidized in a stingle step to CO2 and H2O. Why is it done in so many little steps..

Question

in cells?

Answer 1

The main purpose is because reduction of NADH and FADH2 occur at many steps along the way, which are later used in the electron transport chain, to generate lots of ATP. If it did not pass through all the intermediate steps, and instead went straight to CO2 and water, this yield of ATP would not occur -- and because ATP-generation is the ultimate purpose of metabolism in general, it would be inefficient.

Secondly, many intermediate substrates can be used in other metabolic pathways as well, such as pyruvate, alpha-ketoglutarate, etc, and thus glycolysis and Krebs cycle can serve multiple purposes other than just generating ATP, and so those intermediate steps allow generation and use of those substrates

Answer 2

If you do it in one step then most of the energy will be released as heat. If you do it in many steps, the body has mechanisms to convert the energy into something more useful like ATP (which is used in many of the functions of the cell).

Answer 3

Think how you are going to do it in the lab. Then think if the same thing can be done inside the body.