This is exciting! We talk about anaerobic respiration all the time at YES Mag. Really. We do.

Let's tackle respiration first. Respiration (more commonly called breathing when applied to mammals) is what an organism is doing when it exchanges gas with the environment. The oxygen is transported to the organism's cells. Now, if it's a single-celled organism, the gas exchange happens between the cell and the environment -- through the cell membrane. In plants the exchange happens in special organs called stomates, which are found on the leaves. Plants and animals are dependent on oxygen.

Let's visualize you: you take a breath, and the oxygen is transported via your lungs and blood-stream to your cells. Within your cells, the oxygen reacts with organic compounds such as glucose (provided by your food) to create energy. This chemical reaction also produces carbon dioxide (CO2) and water (H2O). The CO2 and H20 are returned to the environment. Living things that use respiration to create energy are aerobic (oxygen-dependent).

But, some living things -- yeast and some bacteria -- can live without oxygen, they're anaerobic. The yeast and bacteria found in oxygen-deprived environments use compounds such as sulfate, carbonate, or nitrate in place of oxygen. They ferment. The product of fermentation depends on the compounds used and the living organism, but common products are ethanol, lactic acid, and hydrogen. More unusual products would be butyric acid and acetone.

This should be a familiar example: yeast when fermented produces ethanol. Ethanol is an important part of wine-making, beer brewing, and bread making. And, a type of bacteria uses lactic acid fermentation in yogurt to give it that sour taste.

Let's talk about lactic acid a little more -- this is what gets some of us excited here in the office. Why? Because we're in training. Yup. We go out at lunchtime and run or cycle to prepare for our first adventure race. We've been reading a lot about avoiding muscle fatigue. Muscle fatigue happens when you've got too much lactic acid in your muscles.

While our bodies can store glucose (for example, that's what marathoners are doing when they eat lots of pasta the night before a race), we can't store oxygen. Sometimes we can't take in enough oxygen to keep up with our energy needs. When this happens, our muscle cells switch to anaerobic respiration -- instead of reacting with oxygen, the glucose breaks in half and forms lactic acid. Energy is produced, but the lactic acid builds up in our muscles. This build-up makes our muscles feel heavy and they might even cramp up.

The YES Mag Team needs no food-training -- we're already very good at eating big plates of pasta and storing the glucose.