How many ATP molecules are needed to split glucose into two?

Answer 1

This is only half of the picture!

In glycolysis only two ATP's are produced because when glucose is converted to Glucose 6-phosphate, hexokinase requires ATP (first step). On the third step of glycolysis when fructose 6-phosphate gets converted by phosphofructokinase(PFK) into fructo 1,6-biphosphate it als requires ATP. As of now you have used 2 ATP molecules.

after the splitting into glyceraldehyde 3- phosphate you start producing ATP when you convert 1,3-biphosphoglycerate into 3- phosphoglycerate, for a total of 2 ATP ( because you have two molecules of 1,3 biphophoglycerate). You also gain 2 more ATP's on the final step converting phosphoenolpyruvate into pyruvate (because you have 2 molecules of Phosphenolpyruvate)

In summation, you use 2 molecule but you gain 4 molecules which means thay you ultimately have 2 ATP at the end of glycolysis.(2-4=2)

but if you keep looking glycolysis produces 2 NADH (for the electron transport chain) and 2 pyruvate molecules for Krebs cycle.

The transition step makes 2 NADH when converting pyruvate into Acetyl-Coenzyme A.

Also, it produces 2 NADH from the conversion of D-isocitrate into alpha- ketogluterate and again from alpha-ketogluterate into succinyl-Coenzyme A.

and finally when convertin Malate into Ox aloacetate. for a total of 6 NADH

Also 2 GTP's are produced by the conversion of succinyl-Coenzyme A into succinate.

finally, you also produce 2 FADH molecules.

Now all the FADH and NADH go to the ETC

This is where the brunt of the energy is made.

Each FADH molecule produces 2 ATP and each NADH produces 3 ATP... this added witht the glycolysis ATP equals 36 ATP produced by a single molecule of Glucose. (10NADH(3ATP) +2 FADH(2ATP)+ 2 ATP)

Answer 2

2 ATP molecules are used to split glucose. During the process, glucose is split into 2 G3P or glyceraldehyde-3-phosphate molecules.