Cell respiration alternative fuels?

[emmalane]

so I'm having a terrible time trying to answer this question on a biology assignment. Please help me. Thank you.

Briefly explain how a cell can use the same machinery to utilize protein and fat for fuel as it does for glucose. What must happen to the protein and fat molecules before they can be oxidized?

[MrMistery]

that's a stupid question. the cell doesn't use the same machinery for all nutrients. It uses parts of the same machinery, but extra enzymes are needed to utilize non-sugar fuels.

[Jesse2504]

I agree with Mr Mistery,

Fats are broken down into their constituents - fatty acids and glycerol then sent to respective parts of the respiration process, although further processing by enzymes must occur before.

Proteins are broken down into their constituents - amino acids, which are further processed to feed into the respiration process

Basically
low entropy high free energy > high entropy low free energy + energy