Simple answer:
Under the condition of strenuous exercise with inadequate oxygen supply. ;D
Complicated answer:
When your muscle cells are asked to perform work at an easy relaxed pace they take in glucose, fructose or sucrose plus oxygen from the blood, and using the "Aerobic Respiration" method, they generate cellular motion energy without releasing lactic acid.
Read more about that amazing process here:
http://en.wikipedia.org/wiki/Cellular_respiration#Aerobic_respiration
HOWEVER when your muscle cells are asked to perform strenuous work at an over-extended pace, (like your running away from a bear who wants to eat you). Then the oxygen becomes in short supply. There is not enough oxygen supplied by the lungs to increase output under the "Aerobic Respiration" method.
So, the muscle cells, knowing that they will die if they don't produce more energy, have a Plan - B. They can create massive amounts of energy without oxygen with the drawback of creating lactic acid. But that's fine, they will clean up that mess later. They start using an "Anaerobic Respiration" method.
Read more about that here.
http://en.wikipedia.org/wiki/Anaerobic_exercise
The muscle prefers to make energy using "aerobic methods", but in extreme situations, your muscle cells have a "turbo" option: "Anaerobic_respiration".
This Scientific American Article answers your question:
http://www.scientificamerican.com/article.cfm?id=why-does-lactic-acid-buil
And read this:
http://en.wikipedia.org/wiki/Lactic_acid_fermentation
Answer #2:
Your muscle cells will undergo lactic-acid fermentation (Creating cellular energy anaerobically) when there is not enough oxygen in the blood to create cellular energy in the preferred aerobic way.
The most efficient way to metabolize energy is aerobic respiration. However there is not always sufficient oxygen to produce the energy needed to perform certain tasks. During periods of intense activity or oxygen deprivation cells must resort to using anaerobic respiration in the form of lactic acid fermentation.
Lactic acid fermentation is caused when the body is unable to provide cells with adequate amounts of oxygen for aerobic cellular respiration in the mitochondria. This is usually due to exercise.
Lactic acid fermentation can make your muscles sore, so exercising for a long time may result in this.
sleeping
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Wild Guess #2:
Souring of milk.
lactic acid begins and ends in the cytoplasm
When your body has an inadequate supply of oxygen. So, if you were doing strenuous exercise or underwater where there is no oxygen, you'd be undergoing lactic acid fermentation!
1.) Alcoholic fermentation 2.) Lactic acid fermentation
Hot Dilly beans are an example of lactic acid fermentation.
Glucose---Lactic Acid+ Energy
Your muscle cells do when you preform lactic acid fermentation.
Lactic Acid Fermentation and Alcoholic Fermentation.
Human muscle cells undergo lactic acid fermentation in low oxygen conditions.
Yes? lactic acid fermentation produces only lactic acid alcoholic fermentation produces ethanol and co2
Lactic Acid fermentation :)
Lactic acid fermentation produces lactic acid, carbon dioxide, and ATP.
The two types of fermentation are alcoholic fermentation and lactic acid fermentation. Alcoholic fermentation is also referred to as ethanol fermentation.
1.) Alcoholic fermentation 2.) Lactic acid fermentation
Making saurkraut is a lactic acid fermentation.
Hot Dilly beans are an example of lactic acid fermentation.
Glucose---Lactic Acid+ Energy
The fermentation of milk occurs to form curd, of course lactic acid is released.
Your muscle cells do when you preform lactic acid fermentation.
Lactic acid produced by fermentation.