suger or fat

[scifes]

one:
if protien is broken to give fat..fat is broken to give sugars..&
sugar is compressed to give fat..fat is compressed to give protien..

then why dowe need all three of them??

two:
what exact mechanisem makes the body switch from recently "eaten" sugars as an energy source to stored fat as an energy source?? and what does the mechanisem respond to?

 

[EmeraldAxe]

This is an incredibly complex question actually. There are various biochemical cycles employing dozens of different enzymes to explain this. But you can't just convert from one to another without use of energy (ATP, NADPH, etc).

How this happens is 4000 level biochemistry (metabolism). Wikipedia probably has explanations. Otherwise, just take 1st semester biochemistry, boring though.