Cellular Respiration How our body makes ATP, ENERGY!!

Cellular Respiration: An Overview The process by which cells break down food sources such as glucose, fats, and protein and release their stored energy.

Cellular Respiration-Overview Two main types –Anaerobic – no oxygen required –Aerobic – requiring oxygen Both forms produce energy storage molecules called ATP – adenosine triphosphate.

Go To Slides On ATP

ATP: Adenosine Triphosphate ATP is the cells energy currency. Cellular work such as metabolism, transport, and movement is powered by the breakdown of ATP. Energy is released or stored by breaking or making a phosphate bond.

Anaerobic Processes No oxygen is required for these processes. Includes glycolysis (the breakdown of glucose) and fermentation. Bacteria and yeast are examples of anaerobes.

Glycolysis Occurs in the cytoplasm. Breaks down glucose into 2 molecules of pyruvate 2 ATP molecules are formed. 2 NADH electron carriers are also formed.

Glucose To the electron transport chain Glycolysis 2 Pyruvic acid

Glucose To the electron transport chain Glycolysis 2 Pyruvic acid

Glucose To the electron transport chain Glycolysis 2 Pyruvic acid

Summary of Glycolysis Reactants Glucose- (C 6 H 12 O 6 ) 2 ATP Products 2 pyruvic acid 2NADH a net of 2 ATP

Fermentation Occurs after glycolysis if there is no oxygen present. Two types: –Alcoholic fermentation (AF) –Lactic acid fermentation (LAF) Does NOT make ATP Both types break down pyruvic acid & convert NADH back to NAD +

Alcohol Fermentation Bacteria and fungi (yeast) Produces ethyl alcohol and CO 2 Process used to form beer, wine, and other alcoholic beverages Also used to raise dough (bread yeast)

Alcohol Fermentation Diagram

Lactic Acid Fermentation Bacteria, plants and most animals Converts pyruvic acid into lactic acid. It can build up in muscles during strenuous exercise and cause burning and soreness.

Lactic Acid Fermentation Diagram

Aerobic Processes Requires oxygen. Most organisms are aerobes. Equation for Aerobic respiration: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + Energy

Cellular Respiration Flowchart (aerobic) Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) + ATP

The Mitochondria If O 2 is present following glycolysis, pyruvate is modified and enters the mitochondria. Here food is broken down completely.

Mitochondria continued.. Energy storage molecules like NADH and ATP are produced. This is why the mitochondria is called the “power house” of the cell.

Krebs Cycle Overview Occurs in the mitochondrial matrix Reactants: Pyruvic Acid Products: 2 ATP, 2 FADH 2, & 8 NADH –CO 2 as a waste product.

The Krebs Cycle

Citric Acid Production The Krebs Cycle Section 9-2 Mitochondrion

Electron Transport Chain (ETC) Occurs in the inner membrane of mitochondria. Reactants- NADH, FADH 2 Products  32 ATP and H 2 O When you exhale-- the CO 2 and H 2 O in your breath comes from cellular respiration.

Electron Transport Chain

The Role of Oxygen in the ETC O 2 accepts the electrons at the end of the transport chain. O 2 also picks up H+ to form water. ATP is produced as electrons move down the transport chain. ATP Energ y from e - O2O2 H2OH2O

Summary of Cellular Respiration Respiration Process Where Process Occurs Net Gain of ATP Per Glucose Anaerobic: Glycolysis & Fermentation Cytoplasm2 ATP Aerobic: Krebs Cycle and Electron Transport Mitochondrion36 ATP