Which of the following events takes place in the Kreb entry phase (acetyl COA from pyruvate)?

A). Only CO2 output

B). NAD is reduced, CO2 is released

C). NADH is oxidized, CO2 is released

D). Only NADH is oxidized

E). Only NAD is reduceed

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals