its because fat has (more than) twice as many calories as the same weight of carbs or protein. That is, 1 gram of fat provides 9 calories, whereas 1 gram of both carbohydrates and protein provide 4 grams each. ^_^
t’s because fatty acids contain a lot of acetyl groups that can be transfered to the krebs cycle, leading to many protons being pumped by the electron transport chain, and as a result a lot more ATP is formed…
Everything is right – fatty acids store more energy in their chemical bonds than carbs and protein, which leads to more energy production when they are broken down (by the cell this makes ATP). A calorie is just a measure of heat energy, and since the chemical bonds in fats contain more energy fat is more calories.
thanks soooo much for all your answers!!! They were all right! The question has been extra credit in Bio for about 2 months now, and when I finally get the answer, another person got it too 🙁 That sucks! He beat me by like 3 days. But thanks again!