Cellular Respiration
Prokaryotes
2 net ATP from Glycolysis. 36 ATP from Krebs Cycle and ETC =38 ATP Total
Eukaryotes
2 net ATP from glycolysis; 34 ATP from Krebs cycle and ETC; 36 ATP total.
lactic acid fermentation equation
C3H3O3+ NADH> C3H6O3+ NAD+
Fermentation chemical equation
C6H12O6 -> 2C2H5OH + 2CO2
Anaerobic Respiration
Called fermentation. Occurs when oxygen is not present. Oxygen is the final electron acceptor in aerobic cellular respiration. When not present, it cannot occur. Not nearly as efficient as aerobic respiration Only produces 2 ATP molecules. Animals use a different method than others.
Cellular Respiration
Cells release energy from the chemical bonds of food molecules. Every living organism uses cellular respiration.
Aerobic Respiration: ETC
Energy produced from Krebs cycle is passed down an electron transport chain. Oxygen is the final electron acceptor. Together, the Krebs cycle and the ETC produce 34 ATP per molecule of glucose in eukaryotes and 36 ATP per molecule of glucose in prokaryotes.
Lactic Acid Fermentation
Forms lactic acid and carbon dioxide occurs in bacteria (how we get yogurt) occurs in animals (Occurs in your muscles during rapid exercise when the body cannot supply enough oxygen to the tissues. Build up of lactic acid in muscles is what causes painful, burning sensation and eventually muscle fatigue.)
What is the problem?
In a few seconds, all the molecules are filled with electrons causing ATP production to stop.
Eukaryotes
Most steps occur in mitochondria
Alcoholic Fermentation
Mostly occurs in yeast and prokaryotes. Forms ethyl alcohol and carbon dioxide as wastes. Important process in making alcoholic beverages, ethanol based fuels, and even in rising of bread.
Prokaryotes
Occurs in Cytoplasm
Cellular Respiration is very effective if what is present?
Oxygen
Aerobic Respiration: Krebs cycle
The 2 molecules of Acetyl-CoA bind with the 4C molecule called Oxaloacetate and produce a 6C molecule of Citric Acid Therefore, the Krebs Cycle is also called the Citric Acid Cycle. The 6C citric acid molecule is modified and converted in a series of chemical reactions producing Results in production of ATP, NADPH, H2O, and CO2
aerobic respiration: Krebs cycle
The two molecules of pyruvate that were produced in glycolysis move to the mitochondria. Occurs inside mitochondria. Each molecule of pyruvate splits off one carbon. The lost carbon binds with Oxygen to produce CO2 The two remaining carbons are now called Acetyl-CoA (Acetyl Coenzyme A).
Glycolysis
first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid, C6H12O6 is split into two 3 carbon molecules called pyruvate Uses 2 ATP to occur but, produces 4 molecules of ATP= resulting in a net of 2 ATP Also produces 2 NADPH molecules
If oxygen is not present: Anaerobic pathway
glycolysis is followed by a type of fermentation
If oxygen is present: aerobic pathway
glycolysis is followed by the Krebs Cycle and ends with an Electron Transport Chain.
Step 1: Glycolysis
occurs no matter what in cytoplasm only, begins all cellular respiration, no mitochondria needed, releases only a small amount of energy but it is important because it begins the process.
Overview of Cellular Respiration
overview of cellular respiration: glycolysis- occurs in the cytoplasmic fluid + Citric acid cycle- occurs in the mitochondrial matrix= net total 4 ATP per 1 glucose molecule.
Krebs cycle
pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions. 3C Pyruvate>> 2C acetyl- CoA + CO2
After Glycolysis
subsequent steps depend on if oxygen is present or not
cellular respiration
the process by which cells use oxygen to produce energy from food
Although the energy yield from glycolysis is small, the process is so fast that cells can produce how many ATP in just a millisecond?
thousands
