Question

1. Per molecule of glucose, how much NADH is made in total (glycolysis and TCA)?  How many protons are moved across the membrane thanks to this amount of NADH?
2. Per molecule of glucose, how much FADH₂is made?  How many protons are moved across the membrane thanks to this amount of NADH?
3. Per molecule of pyruvate, how much ATP is made through lactic acid fermentation?

Answer 1

GLUCOSE GLYCOLYSIS - → 2 NA DH 2) PYRUNATE LINK REACTION 2 NADH ② ACETYL COA KREBS CYCLE → 6 NADH 2 FADH₂ + 2 ATP

Per molecule of glucose :-
NADH formed -
• 2 in glycolysis
• + 2 in link reaction/ Pyruvate decarboxylation (1 per reaction and 2 reactions by 2 molecules of pyruvate)
• + 6 in krebs cycle (3 per cycle- and 2 cycle occur because of 2 acetyl coA).
Total = 10 NADH

• A total of 10 protons moves across the membrane for one NADH into the electron transfer chain.
So, by 10 NADH - 10×10= 100 protons.

FADH2 formed -
• 2 FADH2 in Krebs cycle ( 1 per cycle)
Total 2 FADH2 formed by one molecule of glucose.

• A total of 6 protons moves across the membrane for one FADH2 into the electron transport chain.
So, by 2 FADH2 - 2×6= 12 protons.

Lactic acid fermentation :-

• There are no ATPs formed by a molecule of pyruvate in this process.
• In this process, one NADH per pyruvate is consumed.
• If glucose molecule goes through lactic acid fermentation, then net 2 ATPs are formed.

2 ADP +2 Pi ZATP GLYCOLYSIS GLUCOSE - PYRUVATE 2 NAD 2 NADH + 2H+ 1. 2 LACTATE E LACTIC ACID DEHYDROGENASE