Question

Why does the mitochondria produce more ATP than glycolysis for each molecule of glucose broken down?

What charges the electrons in the photosystems (the source and the conduit that moves it into the electrons)

Answer 1

During glycolysis, which occur in cytoplasm and does not require mitochondria, net 2 molecules of ATP are produced per glucose molecule where as mitochondria produces about 30 molecules of ATP. This is because, in mitochondria Krebs cycle occurs which completely oxisidises the pyruvate produced by glycolysis into CO2 . Krebs cycle also produces reducing equivalent NADH and FADH2, which finally donate their electrons to the Electron Transport Chain (ETC). This ETC then generates Proton Motive Force (PMF), which is used to synthesize ATP by ATP Synthase enzyme. All these processes don't occur in cytoplasm snd hence only two molecules of ATP are produced in glycolysis, whereas much more are in mitochondria per glucose molecule broken down.

The electrons in the Photosystems are charged by the light. When the Two Photosystems absorb light energy their electron is excited and this electron is fed into the ETC of the chloroplast. The movement of this electron through the various components of the ETC generates the PMF just as In mitochondria. This PMF is used by the ATP Synthase to synthesize ATP. In chloroplast also, NADP+ is reduced by these electrons to NADPH . The oxidised Photosystem II is reduced by the electron from WATER and the Photosystem I is reduced by the electron from Photosystem II after passing through ETC.