fats and energy

[mistique]

Hey everyone.
Does anyone know:
"What is the characteristic of fats that makes them energy dense?"

I would be so happy if u could help me with this as i don't know what the answer could possibly be...
thank-you

[sdekivit]

how are fats stored in cells ? remember cells are in a polar environment and fats are hydrofobic.

[Dr.Stein]

How?

[victor]

I'd say that because the C atom in fats are greatly reducted, so this makes them result more energy when oxidized.

@sdekivit
via ketone bodies? or endocytocys?

[Dr.Stein]

In digestion, fat will be hydrolized into fatty acid and then converted into triacylglycerols by some enzyme to be stored within cell.

[saternet]

Hey everyone.
Does anyone know:
"What is the characteristic of fats that makes them energy dense?"

Fats are basically long hydrocarbon chains. They are so energy dense because of the high potential energy that exists in the carbon-hydrogen and carbon-carbon bonds. Since more bonds are visible in a long hydrocarbon chain than in a glucose or amino acid molecule, fats contain more than double the amount of energy per unit mass. They could be energy dense in macromolecular terms because they exist as saturated in unsaturated.

[g0ld3n88]

Fats contain little water, or h20 which enables it to have more space to be filled with energy.

[JackBean]

Since more bonds are visible in a long hydrocarbon chain than in a glucose or amino acid molecule

You mean like - I can see them -> there is energy... ?
The point is, that in fatty acids you have usually only C-C or C-H bond, whereas in sugars/AA there are plenty other atoms in the molecule, what make them more oxidized and thus you will gain less energy per C atom and thus per dry weight.
The other thing, sugars are highly hydrophilic, so they bind about one their weigth of water, what makes the energy gain per fresh weigth even worse

more space to be filled with energy.

What the hell is that?

[jwalin]

everything is covered
only thing the c-h bond has a higher energy content

@jackbean

more space to be filled with energy.

i think he meant that lesser amounts of other atoms allows you to have more mass and hence number of c-c and c-h bonds per unit length