Why do nuts contain more energy than carbs or protein?

[Roxy]

We did this experiment where we had to burn nuts. And I did not get these questions, can someone help me with them?

1) What part of the nut is burned? (is it the fat part??)
2) What is nut oil composed of?? (is it fat??)
3) Why does "nut" contain more energy than carbs or protein?? (?)

 

[iansmith]

What is the energy/dietary content of your type of nuts? What is the maine ingredient for energy.

As for oil content, it is basically Carbon and hydrogen and the number of carbon will have an impact on the potential energy of the molecule.

 

[Roxy]

What is the energy/dietary content of your type of nuts?
695 kcal/100g??
What is the maine ingredient for energy.
fat, oil?

 

[iansmith]

What is the energy/dietary content of your type of nuts?

I was talking more in the line of the follwing

Walnuts
Protein 17.148 g
Total lipid (74.244 g
Carbohydrate 22.008 g
Fiber 5.760 g

http://www.moondragon.org/nutrition/foodguide/nutwalnut.html

That give you what part could be burned.

What is nut oil composed of

Satured fatty acid, unsaturated, cholesterol, etc.

 

[Roxy]

I think I got it now. Thank You :)

 

[endeavour]

We did this experiment where we had to burn nuts. And I did not get these questions, can someone help me with them?

1) What part of the nut is burned? (is it the fat part??)
2) What is nut oil composed of?? (is it fat??)
3) Why does "nut" contain more energy than carbs or protein?? (?)

Yep the oil is fat ( or triglycerides).


The nut "contains" more energy (releases more energy) because chemically, it has the most potential to create C=O bonds (carbon double bond to oxygen) in $$CO_2$$, which releases the most energy (exothermic).
This process in oxidation.
Carbohydrates are already partially oxidised, because they already contain many -OH bonds (have a look at the molecular structure of, say, glucose), so they don't release as much energy as fats.

 

[Roxy]

Yep the oil is fat ( or triglycerides).


The nut "contains" more energy (releases more energy) because chemically, it has the most potential to create C=O bonds (carbon double bond to oxygen) in $$CO_2$$, which releases the most energy (exothermic).
This process in oxidation.
Carbohydrates are already partially oxidised, because they already contain many -OH bonds (have a look at the molecular structure of, say, glucose), so they don't release as much energy as fats.

Do priteins also contain -OH bonds ??
Thanks

 

[endeavour]

Do priteins also contain -OH bonds ??
Thanks

I see where you're coming from.
But actually proteins don't really. Fats release more energy (39.4 kJ/g) than proteins (17.9 kJ/g) and carbohydrates (15.8kJ/g) - they have very long chains of -C-H bonds and have more potential to make CO2[/size] (and H2[/size]O. as oxidation produces water and carbon dioxide) as I mentioned above. In my posts I should've add a bit more detail and mentioned that the carbohydrates bonds are -C-O-H bonds (ie they have some CH bonds too, but they are partially oxidised). Proteins have a few -C-H bonds in comparison to fats.

*data was from my biology book, and as you can see carbohydrates and proteins are actually similar in releasing energy.