My name is David, I am on Planet Earth.
In ethanol fermentation. One glucose molecule breaks down into two pyruvates (1). The energy from this exothermic reaction is used to bind inorganic phosphates to ADP and convert NAD+ to NADH. The two pyruvates are then broken down into two Acetaldehyde and give off two CO2 as a waste product (2). The two Acetaldehydes are then converted to two ethanol by using the H+ ions from NADH; converting NADH back into NAD+ (3).