Ahhh, that lovely process of fermentation! We all know it and appreciate it, or at least those of us that drink alcoholic beverages do ;) But have you ever really thought about the chemistry behind it?
Let’s look at yeast shall we?
Yeast are eukaryotic cells, just like ours. Yes, I know it’s hard to imagine you have anything in common with a lowly yeast but you’ll just have to get over it. They contain a nucleus, membrane-bound organelles, all the things that our cells have. We are just a combination of lots of them.
Just to clarify, I meant lots of cells not lots of yeast ;)
Our cells require a lot of energy, some cells more than others. Muscle and nerves really need a steady supply of energy so the cells can perform various metabolic functions. Our cells use one molecule in particular, ATP, as their batteries. The ATP molecule is charged with energy-rich phosphate bonds and when these bonds are broken, cells can use that energy for all sorts of things.
The process for charging the batteries is called cellular respiration. No, it’s a different kind of respiration than your lungs do. This process takes glucose (as well as other molecules) and can use that simple carbohydrate to charge lots of ATP molecules. The thing is, for this cellular respiration to occur, there has to be enough oxygen.
I can see you rolling your eyes and saying, “Well, der, we breathe oxygen all the time!” And while this is true, most of you have at some point have felt the after-effects of the process that occurs in cells that happens when there isn’t enough oxygen present.
And that, my friends, brings us to fermentation. The process is an alternate pathway where the sugars get turned into acids rather than ATP. It’s only temporary and the acid gets broken down as soon as oxygen levels return to normal. Most of you have felt this if you have ever overdone your work-out. That burn you get the next day when you can’t walk? That’s lactic acid that has built up in your muscle tissue. Fun, huh? Yeah, not so much. But the good news is, the pain doesn’t last forever as the lactic acid is eventually converted back to a molecule that can continue through cellular respiration and more ATP can be made.
But lactic acid isn’t the only thing that comes from fermentation. Ethanol is also a by-product of this process.
Can you imagine what it would be like if humans produced ethanol as a result of the process of fermentation instead of lactic acid??!!??
Human goes to the gym, lifts some weights and ends up sloshed off his butt! *crying laughing*
If we could do this, I bet gym memberships would skyrocket… ;)