O2 is the final e- acceptor in oxidative phosphorylation. where does these e- come from ?

gag reflex, poor dentition, gum retraction

have a good day

not always but somethings can be reproduced in a laboratory.

other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. the si derived unitsfor these derived quantities are obtained from these equations and the seven si base units.