210 likes | 328 Views
Cell Respiration. Cell Respiration. Cell Respiration: catabolic process Consume Oxygen and Sugars Creates Carbon Dioxide, Water, and ATP Change in G(Free energy)= -686 kcal/ mol Combination of oxidation and reduction reactions Oxidations: Loss of electrons
E N D
Cell Respiration • Cell Respiration: catabolic process • Consume Oxygen and Sugars • Creates Carbon Dioxide, Water, and ATP • Change in G(Free energy)= -686 kcal/mol • Combination of oxidation and reduction reactions • Oxidations: Loss of electrons • Reduction: Addition of electrons (reduce or make more negative charge)
Cell Respiration • Sugars are good fuel because their electrons want to move • Oxidation and reduction happens easily • Little activation energy required • BUT Sugars need to be broken down part by part • This is more energy efficient • Hydrogens are moved to Oxygen after being passed to a coenzyme NAD+ (Oxidizing agent.) • H + NAD+ NADH (Neutral)
Cell Respiration • Electron Transport Chain: breaks the fall of electrons to oxygen into several steps. • Controls energy release • Reduces lost energy in the process • Occurs in INNER MEMBRANE of mitochondria • Movement of electrons in Cell Respiration • Food NADH Electron Transport Chain Oxygen
Cell Respiration • Stages of cell respiration • Glycolysis • Citric Acid • Oxidative Phosphorylation
Cell Respiration • Glycolysis • Occurs in Cytosol/Cytoplasm outside of Mitchondria • Breaks down glucose into pyruvate • Citric Acid Cycle • Occurs in mitochondrial matrix • Oxidizing broken down pyruvate to Carbon Dioxide • Both involve reduction with NAD+ • Oxidative Phosphorylation • Inner Membrane of Mitochondria • ATP Synthesis • Through reduction/oxidation reactions
Cell Respiration • Glycolysis: “Splitting of sugar” • Glucose 2 Pyruvate + 2H2O • + 4 ATP, - 2 ATP • 2 NAD+ + 4 e- + 4 H+ 2 NADH + 2 H+ • Breaks the ring glucose into 2 straight sugars • Each straight sugar is transformed by enzymes to be pyruvate • Release 25% of the energy in glucose
Cell Respiration • Citric Acid Cycle: • Pyruvate enters mitochondria through ACTIVE TRANSPORT • NAD+ NADH • Pyruvate converted to Acetyl CoA • Process supported by an enzyme at each step • Overall • 3NAD+ NADH • FAD+ FADH2 • 2C2O • 1 ATP (Through GTP)
Cell Respiration • Oxidative Phosphorylation • Combines the electron transport chain with chemiosmosis • Example of ENERGY COUPLING AND CO TRANSPORT • Electrons are added to electron transport chain from • NADH • FADH2 • Cytochromes • ELECTRON TRANSPORT CHAIN MAKES NO ATP DIRECTLY • BUT HELPS IT INDIRECTLY
Cell Respiration • Chemiosmosis: Creating a membrane potential by removing H+ out of the Mitochondria ACTIVELY and then using its return to drive the synthesis of ATP • Mitochondria pumps Hydrogen Ions out with Electron Transport Chain • Electron transport chain is a series of integral proteins in the INNER MEMBRANE of the mitochondria • Once hydrogen ions are pumped out, membrane potential is created so the hydrogen ions want to diffuse back inside the Mitochondria. • The Hydrogen moves through another integral protein ATP SYNTHASE • ATP Synthase makes ATP as Hydrogen moves through it.
Cell Respiration • Overall Cell Respiration: • Change in G = -686 kcal/mol • 36-38 ATP Created • 7.3 kcal/mole to make ATP • 7.3 x 38/686 =0.4 • 40% efficiency for transferring energy • The rest is lost in heat
Cell Respiration • Aerobic: Respiration with oxygen • Anaerobic: Respiration without oxygen • Fermentation: Glycolysis which transfers electrons to Pyruvate so that they can be used again for another cycle glycolysis • Two Types of Fermentation: • Alcohol: Pyruvate converted to ethanol • Bacteria/yeast both do this • Creates beer • Lactic Acid: pyruvate converted to lactate • No CO2 created