Hi! I'm Emma, welcome to my biology vlog. Today I'm going to talk about cellular respiration. How do we get energy? Cellular respiration is the chemical process that releases energy from food and converting it into energy that is stored in ATP.
Cellular respiration has three main stages: glycolysis, the Krebs cycle, and the electron transport chain. 36 molecules of ATP are produced per molecule of glucose. This equation represents cellular respiration C6H12O6+6O->6CO2+6H20+ATP Glucose, Oxygen, Carbon Dioxide, Water, and Energy
The first stage is glycolysis and it takes place in the cytoplasm. In glycolysis 1 molecule of glucose (6 carbon compound)splits into 2 molecules of pyruvic acid (3 carbon compound). glycolysis means "splitting apart". 2 ATP molecules and NADH are gained in this process.
If there is oxygen (aerobic), it continues to the Krebs cycle which occurs in the matrix of the mitochondrion. During the Krebs cycle pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions. 2 ATP molecules are gained in addition to CO2, NADH, FADH2.
Then for the third stage is the electron transport chain. this occurs in the inner membrane of the mitochondrion. During this process, the high energy electrons (NADH, FADH2) from glycolysis and Krebs cycle convert ADP to ATP. 32 ATP molecules are produced in the electron transport chain.
If there is no oxygen (anaerobic), it goes from glycolysis to fermentation. Fermentation releases energy from food molecules by producing ATP. Yeasts uses alcoholic fermentation which produces ethyl alcohol and CO2 but most use lactic acid fermentation which converts pyruvic acid to lactic acid.