Calorie Consumption

<p>I just had this random thought in my head. Is there an average calorie consumption versus total calories? </p>

<p>For example, if I eat something that is labeled to have 100 Calories, how much of that is actually converted from potential energy into ususable energy? Some of it is lost because food gets stuck on teeth, etc. When food is ultimately converted into waste, doesn't that waste still have some potential energy? When a bag of potato chips says it has 100 Calories per serving, how much of that on average do we actually utilize (assuming none is turned into fat and stored in the body)? Is this a negligible amount?</p>

<p>Sorry, this is really stupid, but I've been mulling over this and I'm just curious. If my question is vague, please feel free to tell me. Thanks</p>

<p>Never thought of that. But, sorry, I hated bio.</p>

<p>60-75% in humans. Calories is a measure of energy, and the other 40% is lost as heat.</p>

<p>Of the total potential energy, humans absorb 60-75% and the remainder is lost? Wouldn't heat loss still be 'processed' energy (since it's still being processed by the organism). I'm not talking about solely mechanical energy but all energy that is absorbed and processed (even if it is converted into heat).</p>

<p>I was tanning out in the sun the other day and I thought that I was gaining energy from the sun. And then i realised that I didn't have photosynthetic cells in my body, to convert the solar energy into chemical potential energy. woooo big words</p>

<p>anyway I heard the same as tufts and krabble</p>

<p>The combustion of a mole of glucose produces ~2800 kJ or ~670 Calories. A mole of glucose can also be used to produce 36 moles of ATP, and each mole of ATP can produce 12 Calories when it is turned into ADP. 36 moles of ATP produces 432 Calories. This is something like 64% efficiency.</p>

<p>Wow thanks for that overview. Is this something taught in AP Bio?</p>

<p>What happens to the remaining ~36% of energy?</p>

<p>Yes, it's from AP Bio. I actually don't really know what I'm talking about, and I'm probably wrong. If all the stuff is completely oxidized in aerobic respiration, I would assume that the rest of the energy gets turned into heat or something. Which isn't necessarily wasteful; you gotta use energy to maintain your body temperature.</p>

<p>i love you all.</p>