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Chemical energy and food Where do organisms get energy? Organisms get the energy they need from food Cells don’t just eat and burn the energy they store some, get the protein they need, and capture the little bit of chemical energy.

Overview of cellular respiration What is cellular respiration? Cellular respiration is the process that releases energy from food in the presence of oxygen. 602 + c6h1206 6co2 + 6h2o +energy

Stages of cellular respiration Cellular respiration captures energy from food in three main stages- glycolysis, the Krebs cycle, and the electron transport chain.

Oxygen and energy Pathways of cellular respiration that require oxygen are said to be aerobic (“in air”) Glycolysis is said to be anaerobic (“without air”).

Comparing photosynthesis to cellular respiration What is the relation ship between photosynthesis and cellular respiration? Photosynthesis removes carbon dioxide from the atmosphere, and cellular respiration puts it back. Photosynthesis releases oxygen into the atmosphere, and cellular respiration uses that oxygen to release food.

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Glycolysis What happens during the process of Glycolysis? During glycolysis, 1 molecule of glucose, a 6-carbon compound, is transformed into 2 molecules of pyruvic acid, a 3-carbon compound. The first set of reaction in cellular respiration I glycolysis

ATP production Even though glycolysis is an energy-releasing process, the cell needs to put in a little energy to get things energy.

NADH production One of the reactions of glycolysis removes 4 electrions, now in a high-energy state, and passes them tom an electron carrier called NAD+, or nicotinamide adenine dinucleotide.

The advantages of glycolysis The speed of glycolysis can be a big advantage when the energy demands of a cell suddenly increase. Besides speed, another advantage of glycolysis is that the process itself does not require oxygen.

The Krebs cycle What happens during the Krebs cycle? During the Krebs cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions The cycle is named after a British biochemist Hans Krebs

Citric acid production The matrix is the innermost compartment of the mitochondrion and the site of the Krebs cycle reactions.

Energy extractions Energy is released by the breaking and rearranging of carbon bonds, is captured in the forms of ATP.

The process of cellular respiration SC.912.L.18.8 Electron Transport and ATP Synthesis How does the electron transport chain use high-energy electrons from glycolysis and the Krebs cycle? The electron transport chain uses the high-energy electrons from glycolysis and the Krebs cycle to convert ADP into ATP The electron transport chain is the last step of cellular respiration

The process of cellular respiration SC.912.L.18.8 Electron Transport NADH and FADH2 pass their high-energy electrons to the electron transport chain Oxygen is the final electron acceptor in the electron transport chain The end of a transport chain is an enzyme that combines the electrons with hydrogen ions and oxygen to form water

The process of cellular respiration SC.912.L.18.8 ATP Production The cell uses a process called chemiosmosis to produce ATP. In this ATP synthases grabs an ADP molecule and attaches a phosphate group producing ATP The full length of the electron transport chain provides enough energy to produce 3 ATP molecules

The process of cellular respiration SC.912.L.18.8 The Totals How much ATP does cellular respiration generate? All together glycolysis, Krebs cycle, and the electron transport chain releases about 36 molecules of ATP per glucose molecule The 36 ATP molecules generated represents about 36 percent of the total energy of glucose. The other 64 percent is released as heat.

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Alcoholic Fermentation Fermentation SC.912.L.18.10 Alcoholic Fermentation An example of one type of fermentation is alcoholic fermentation This type of fermentation produces ethyl alcohol and carbon dioxide. Yeast and the production of alcoholic beverages use this type of fermentation Pyruvic acid + NADH = Alcohol + CO2 + NAD+

Fermentation SC.912.L.18.10 Fermentation Fermentation is the process by which cells release energy in the absence of oxygen How do organisms generate energy when oxygen is not available? In the absence of oxygen, fermentation releases energy from food molecules by producing ATP.

Lactic Acid fermentation Fermentation SC.912.L.18.10 Lactic Acid fermentation An other example of fermentation is lactic acid fermentation This is the most common fermentation carried out by organisms Lacctic acid fermentation unlike alcoholic fermentation does not give off carbon dioxide Pyruvic acid + NADH = lactic acid + NAD+

Fermentation SC.912.L.18.10 Energy and exercise How does the body produce ATP during different stages of exercise? The body produces ATP during different stages of exercise through cellular respiration and lactic acid fermentation

Fermentation SC.912.L.18.10 Quick Energy When your body needs quick bursts of energy it uses ATP produced by fermentation The fermentation used to produce the ATP is lactic acid fermentation The ATP the body uses when in need of those quick bursts of energy are already in your muscles

Fermentation SC.912.L.18.10 Long-term Energy Some times your body needs long bursts of energy, and for that it uses cellular respiration. Cellular respiration is the only way to continue generating a supply of ATP when exercising for longer then 90 seconds Cellular respiration releases energy slower than fermentation does which is why everyone evidentially gets tired.