2To the electron transport chain Respiration without oxygen is called: Anaerobic Respiration.The first part of Anaerobic respiration is the same as Aerobic : GlycolysisTo the electron transport chainPyruvic Acid
3To the electron transport chain Glycolysis used 2 ATPTo the electron transport chainPyruvic AcidBroke into two 3-Carbon molecules called Pyruvic acid
4Glycolysis produced:2 net ATP’s (4-2 = 2)2 NADHNow if Oxygen is not present, there are two pathways the pyruvic acid can take:Alcoholic Fermentation (does not occur in humans!)Lactic Acid Fermentation
51. Alcoholic fermentation After Glycolysis, you are left with 2 pyruvic acids, 2 NADH and 2 ATP.GlycolysisCPyruvic AcidAn enzyme “pyruvate decarboxylase” also attaches to the pyruvic acid causing it to release a CO2 molecule and leaving a 2 carbon molecule.pdCCCAcetaldehydeO
6NADH gives back 2 high energy electrons to the pyruvic acid and turns back into NAD+ Then another enzyme (alcohol dehydrogenase) turns the 2-Carbon molecule into Ethyl alcohol.CahEthyl alcohol
7Alcoholic fermentation by yeast is the most familiar form you might know. Yeast eat the glucose and convert it into ethanol which is a form of alcohol, and carbon dioxide…Beer… is made with yeast who eat the glucose, make the liquid alcoholic, and the CO2 is the little bubbles you see in beer.
8Yeast is also used in baking not to make alcoholic bread, but for Carbon dioxide. The released gas puts small gas pockets through out the dough causing your bread to have that holed texture.
9So in a chemical equation: Pyruvic acid + enzymes + NADH → alcohol + CO2 + NAD+Now let’s look at Lactic acid fermentation which does occur in your body.Again we begin just after Glycolysis with the forming of pyruvic acid. So we start with 2 ATPCGlycolysis
10NADH plus an enzyme (lactate dehydrogenase) both act on the 3-Carbon pyruvic acid. ldCNADNADHThis causes the 3-Carbon molecule to chemically change into a 3-carbon molecule called “Lactic Acid”CCC
11So chemically: Pyruvic acid + enzyme + NADH → Lactic Acid + NAD When running hard, you normally do not breathe enough oxygen to keep up with the demand that your muscles are asking for.Since there is limited oxygen, your muscles start to produce ATP through lactic acid fermentation.This acid starts to cause a burning sensation over your muscles.
12When using your muscles during some form of exercise…you ever get a cramp? What has happened is that the pyruvate in the muscle has to feed the muscle without oxygenYou are pushing yourself as hard as you can….So because the muscles themselves are using up most of the oxygen, your body converts pyruvate into lactate to get you ATP to continue..After a short period of time you muscles start to hurt. This is because the lactic acid has built up so much on your muscles…you cramp in pain.
13So how do you get rid of the lactic acid on your muscles then? Oxygen! You need to breathe to break down the lactic acid, so many athletes inhale pure oxygen afterwards…You , just rest and breathe real hard…
14So what method is best?Cellular respiration for energy ORlactic acid fermentation.For quick burst of energy “fight or flight” reflex you normally use lactic acid fermentation.For most others, you use cellular respiration, but it releases energy more slowly, so you tend to pace yourself over longer times so you won’t cramp up or become too exhausted.
15Comparing Photosynthesis & Cellular Respiration FunctionLocationReactantsProductsEquationEnergy CaptureEnergy ReleasedChloroplastsMitochondriaCO2 and H2OC6H12O6 (glucose) and O2C6H12O6 (glucose) and O2CO2 and H2O6 CO2 + 6 H2O → C6H12O O2C6H12O O2 → 6 CO2 + 6 H2OEnergyEnergyCreaturePlants, algae, some bacteriaAnimals, some bacteria