Total ATP molecules formed from 1 glucose molecule are :- [40ATP]

Let's divide in 2- parts.

1- In cytoplasm

Glycolysis takes place ( common for both aerobic and anaerobic)

       Glucose ----------------> 2 pyruvic acid

Steps where ATP used

• Glucose--------> Glucose-6-phosphate
• Fructose-6-phosphate -------> Fructose 1,6-biphosphate

Steps where ATP released

• 2 × [1,3 biphosphoglyceric acid -------------> 3 phosphoglyceric acid]
• 2× [2phosphoenolpyruvate ------->pyruvic acid]

Steps where NADH H^+ Formed

• 2× [Glyceraldehyde-3-phosphate-------> 1,3 biphosphoglyceric acid]

Conclusion

• 2ATP used ,4ATP released and 2NADH H^+ formed.

In aerobic respiration Pyruvic acid transported to Mitochondria.

2 - In Mitochondria( aerobic)

A- In Mitochondrial matrix
       

    

• 2 Pyruvic acid --------------> 2 Acetyl CoA releasing 2 molecule of NADH H^+

   

• Each Acetyl CoA molecule enter in Citric acid cycle , from each cycle 3-NADH H^+ , 1-FADH2  AND 1-GTP Molecules formed.

So from 2-cycle 6-NADH H^+ , 2-FADH2 nad 2-GTP molecule formed.

Steps where NADH H^+ formed

• Citric acid -------->  alpha ketoglutaric acid
• Alpha ketoglutaric acid ------> Succinyl CoA
• Malic acid --------> Oxaloacetic acid

Steps where FADH2 formed

• Succinic acid ----------> Fumaric acid

Steps where GTP formed

• Succinyl CoA -----------> Succinic acid

Conclusion

• 2 NADH H^+ , 6NADH H^+ , 2FADH2 ,2 GTP are formed in Mitochondrial matrix

B- Inner Mitochondrial membrane( ETS Present)

• From 1NADH H^+  3-ATP  formed.
• From 1 FADH2  2-ATP formed.
• 1 GTP equivalent to 1 ATP

CALCULATION :

• Total NADH H^+ = 2(CYTOPLASM)+ 8(MITOCHONDRIAL  MATRIX) = 10

• Total FADH2 =2 

•  Total GTP=2 i.e. 2ATP

Total ATP formed  = 4(cytoplasm) + (10NADH H^+) ×3 + (2FADH2)×2 + 2GTP
     = 4+30+4+2
     =40 ATP

NET GAIN = TOtal formed - Total consumed
                   =40 - 2 (cytoplasm)
                   =38ATP

Efficiency

• 1 mole of ATP convert into ADP releasing approx 7.3 Kcal (energy store in phosphoanhydride bond)
• 1 mole of glucose have approx 686 Kcal (energy store in C-C bond)

So , energy store in ATP = (38×7.3)/686

           =0.40

           =40% Of glucose

This ATP used in mechanical work like running , walking etc...( Loss of energy in form heat etc..) So efficiency of human body decrease and it is approximately     20-25%.

NOTE:- In anerobic respiration only glycolysis responsible for formation of ATP.
So, Total ATP formed in anaerobic respiration from 1 glucose molecule is 4 and net gain is 2ATP.

Efficiency =( 2×7.3)/686 =0.02 =2%