Miss Colabelli/Mrs. McDonough Cellular Respiration Chapter 9 Miss Colabelli/Mrs. McDonough

Cellular Respiration Complex process that our cells make ATP by breaking down organic compounds Organisms that use cellular respiration are known as heterotrophs

Cellular Respiration Cellular Respiration is the process that releases energy by breaking down food molecules in the presence of oxygen C6H12O6 + 6O2 6CO2 + 6H2O + ATP Same equation for photosynthesis JUST BACKWARDS!

Glycolysis Process where one molecule of glucose is broken in half, producing two 3-carbon molecules of pyruvic acid Creates a small amount of ATP and NADH Process is anaerobic Does not require oxygen

Aerobic Respiration If oxygen is present in cell environment Pyruvic acid is broken down to make a large amount of ATP If no oxygen is available for the pyruvic acid Fermentation

Fermentation Releases energy from pyruvic acid without oxygen Two types Lactic Acid Alcoholic

Lactic Acid Fermentation Lactic Acid is produced by muscles during rapid exercise when the body cannot supply enough oxygen http://www.youtube.com/watch?v=K_JFBxRBe9Q http://www.youtube.com/watch?v=rGaP9nE8d9k http://www.youtube.com/watch?v=X-ZZETT6F-s

Alcoholic Fermentation Alcoholic fermentation is done by yeasts and some microorganisms Produces an alcohol & Carbon dioxide

Glycolysis First part of cellular respiration Process where a glucose molecule is broken down into 2 molecules of pyruvic acid Glucose  2 pyruvic acid molecules

Fermentation Anaerobic process after glycolysis Pyruvic acid is used to become either lactic acid or ethyl alcohol

Lactic Acid Fermentation Pyruvic acid  lactic acid Important for making dairy products Produces certain cheeses and yogurts Occurs naturally in your muscles when you work out Muscle soreness

Lactic Acid Fermentation Muscles use up all available oxygen Switch to anaerobic respiration Increases acid levels in muscles causing the fatigue Eventually gets processed in liver back to pyruvic acid

Alcoholic Fermentation Pyruvic acid  ethyl alcohol Ethyl alcohol is a 2-carbon molecule Pyruvic acid loses a carbon by releasing CO2

Alcoholic Fermentation Yeast needs to get food to survive such as sugars from fruit Yeast breaks down to ferment the pyruvic acid into ethyl alcohol and CO2 If CO2 is released, you get regular alcohol Ex: wine If CO2 is not released, you get sparkling alcohol Ex: Champagne

The Krebs Cycle Cycle discovered by scientists Hans Krebs During the Krebs Cycle, pyruvic acid is broken down into carbon dioxide in a series of reactions Net ATP Production is 2 ATP

Electron Transport Chain The electron transport chain uses the high- energy electrons from the Krebs Cycle to convert ADP to ATP Total ATP produced: 32

Aerobic Respiration Only occur in the presence of oxygen Two stages Krebs Cycle Electron Transport Chain with chemiosmosis Prokaryotes Occur in cytoplasm Eukaryotes Occur in mitochondria

The Krebs Cycle Five steps in the Krebs Cycle Occurs in mitochondrial matrix Citric Acid is made in Step 1 therefore this is also called the Citric Acid cycle Net ATP produced is 2 ATP

Electron Transport Chain Uses the high-energy electrons from the Krebs Cycle to convert ADP to ATP Total net ATP produced is 34!! Prokaryotes Occurs on cell membrane of organism Eukaryotes Occurs in the mitochondria membrane called cristae

Importance of Oxygen The only way to produce ATP is by the movement of electrons in the ETC Oxygen is the final acceptor Without oxygen, the ETC would halt

Efficiency of Cellular Respiration Glycolysis 2 ATP Krebs Cycle 2 ATP Electron Transport Chain 32 ATP Total = 36 ATP

Summary Aerobic respiration Anaerobic respiration Glycolysis Krebs cycle and ETC Anaerobic respiration Fermentation Alcoholic Lactic acid

Comparing Photosynthesis & Respiration Cellular Respiration Function Energy Storage Energy Release Location Chloroplasts Mitochondria Reactants CO2 and H2O C6H12O6 and O2 Products Equation 6CO2 + 6H2OC6H12O6 + 6O2 C6H12O6 + 6O26CO2 + 6H2O