How Does Cellular Respiration Generate Heat?

[AI_Dave]

Hello,

As you can tell I'm new here. I'm not into science generally but I have come across some discussions online that have gained my interest. So I would like to get a basic understanding of a few things that I don't understand.

So my question is, do cells generate heat? And I what I mean is does a human's cell actually heat to burn food and turn it into energy? From what I've read so far is that a cell will change the food molecules through a chemical reaction into a energy that the body can use. Does this process involve or produce heat in anyway?

And I'll apologize in advance if I'm coming off as a idiot. I am a science and biology newbie but I'm curious to learn more. Thanks!

 

[SteamKing]

Hello,

As you can tell I'm new here. I'm not into science generally but I have come across some discussions online that have gained my interest. So I would like to get a basic understanding of a few things that I don't understand.

So my question is, do cells generate heat? And I what I mean is does a human's cell actually heat to burn food and turn it into energy? From what I've read so far is that a cell will change the food molecules through a chemical reaction into a energy that the body can use. Does this process involve or produce heat in anyway?

And I'll apologize in advance if I'm coming off as a idiot. I am a science and biology newbie but I'm curious to learn more. Thanks!

Yes, cells do generate heat, under certain circumstances.

Each cell contains one or more special parts or organelles called mitochondria (singular, mitochondrion). The mitochondria are the parts of the cell which take nutrients and produce energy, sometimes in the form of heat, through various biochemical processes:

https://en.wikipedia.org/wiki/Mitochondrion

 

[Bystander]

Does this process involve or produce heat in anyway?

Certainly. Google "metabolism, metabolic processes."

 

[AI_Dave]

Thanks for the speedy replies!

 

[mfb]

Yes, cells do generate heat, under certain circumstances.

Certain circumstances as "being alive". Nearly all chemical reactions release a bit of heat, and a cell needs chemical reactions to live (by definition).

 

[SteamKing]

Certain circumstances as "being alive". Nearly all chemical reactions release a bit of heat, and a cell needs chemical reactions to live (by definition).

Yes, that's true. But the mitochondria do much more to promote cellular metabolisms than just "generate heat". One of the many functions performed by the mitochondria is to produce adenosine triphosphate (ATP), a key chemical which is used by cells to generate energy in order to remain "alive".

https://en.wikipedia.org/wiki/Adenosine_triphosphate

 

[mfb]

Sure, heat is a side-product (in most cases). It is unavoidable.

 

[Andy Resnick]

<snip>So my question is, do cells generate heat? A<snip>

As others have mentioned, waste heat is a (required) side-effect of metabolic reactions. That said, there are cells whose primary function is to generate heat (brown fat, or brown adipose tissue).

Your question is well-timed; there's an ongoing back-and-forth argument about the ability to thermally image cells:

http://www.nature.com/nmeth/journal/v11/n9/full/nmeth.3073.html?message-global=remove

 

[256bits]

Combustion of glucose with oxygen can be done in the air and will release around 2880 kJ/mole of heat.
The products formed will be water and carbon dioxide.

The cell, through a slower process and multiple steps, does a similar sort of thing -ie combustion of glucose within its cell wall, but is a much slower process occurring by means of complex chemical reactions known as cellular respiration or metabolism.

The overall equation is
C6H12O6 + O2 = CO2 + H2O + heat( energy released )

and one can use the enthalpy of formation of reactants and products to determine the amount of heat released at the chosen temperature and state of reactant and products.

Of course, in a cell, not all the energy released immediately as heat. Some is used for locomotion, be it by walking around or pumping blood around your body, stored as fat, or bulking up your body in size by cell division, or muscle growth. the cell can use 2 types of respiration, aerobic or anerobic ( with or without oxygen)

In the end though, it all ends up as heat.