Co2 from respiration-Sugars vs Fats

[key]

So more co2 is produced from glucose than from fat; correct?

Say you had two 2000cal diet one being 60%carb and the other 30%carb, how much more co2 would you produce on 60% carb?

Thank you

[JackBean]

That's because fats are more reduced thus you get more energy (calories) per molecule or weight.

[key]

okay so are fats more reduced because sugar has more oxygens?

[JackBean]

yes, that's kind of the point

[key]

so if I compared (3) c6h12o6 and (1) c18h36o2 would the sugars make 8 more co2 than the fat?

[JackBean]

1) the atoms are capitals
2) why do you think that sugar would make 8 more CO2?

[key]

C18H36O18 vs C18H36O2, sugar has 16 extra oxygen, so 16O pick up 8C and make 8CO2?

[JackBean]

and where will you get the carbons?

[key]

lol idk, is the extra co2 just from pyruvate dehydrogenase step? so C18H36O18 vs stearic acid would only give 6 extra co2 since that would be (6) C3H6O3

[JackBean]

No, it's C6H12O6, which will give only 6 CO2, stearic acid is C18HsomethingO2, which will give 18 CO2 with the oxygens coming somewhere from water

[key]

okay I'm obviously a noob

my understanding:
you get 3 CO2 during the process pyruvate-->energy

you get 2 CO2 during the process Aceytl-CoA-->energy

so C6H12O6 would make 6 CO2 and 36 ATP

stearic acid would make 18 CO2 and 120 ATP

so 120 ATP of sugar = 20 CO2?

[JackBean]

That seems about right.