In cellular respiration, where do the high-energy electrons that move through the electron transport chain originate?

The electrons are carried to the ECT by NADH and FADH+, which are reduced during glycolysis, pyruvate oxidation, and the Krebs cycle.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.