cell respiration

Cellular Respiration: Harvesting Energy from Carbohydrates and Other Fuel Molecules Objectives Name and describe the four major stages of cellular respiration. Explain what an oxidation–reduction reaction is and why the breakdown of glucose in the presence of oxygen to produce carbon dioxide and water is an example of an oxidation–reduction reaction. Describe two different ways in which ATP is generated in cellular respiration. Write the overall chemical equation for glycolysis, noting the starting and ending products and highlighting the energy-storing molecules that are produced. Describe two different metabolic pathways that pyruvate can enter. Name the products of the citric acid cycle. Describe how the movement of electrons along the electron transport chain leads to the generation of a proton gradient. Describe how a proton gradient is used to generate ATP. Explain how muscle tissue generates ATP during short-term and long-term exercise. The BIG picture What is the function of Cellular respiration? breaks down carbohydrates, lipids, and proteins converts energy in fuel molecules into ATP allows the cell to do the work. Generating ATP Equation for Cell Respiration The process of making sugar (photosynthesis) and using sugar to make ATP (respiration) occur via a series of oxidation/reduction reactions. Why? Why must there be so many steps???? CONTROL! First, Redox reactions and Energy Carriers First, a look at oxidation and reduction LEO the Lion says GER: Lose Electrons Oxidation…..Gain Electrons Reduction Carbohydrate Catabolism Carbohydrate catabolism and Electron Carriers Energy Intermediates-NAD+/NADH http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20101/bio%20101%20lectures/energy/energy.htm Flavin Adenine Dinucleotide (FAD) Glycolysis Pyruvate oxidation Citric acid cycle Glucose NADH Pyruvate Acetyl-CoA FADH2 ATP NADH NADH NADH NADH ATP ATP ATP ATP Energy released is stored as ATP and electron carriers. Change in free energy, DG (kcal/mol) Electron Carriers Cellular Respiration Stages Glycolysis (cytoplasm) Pyruvate oxidation (mitochondria) Citric acid cycle (mitochondria) Oxidative phosphorylation (mitochondria) Carbohydrate Catabolism CO2 O2 H2O Substrate-level phosphorylation Oxidative phosphorylation Electron transport chain Electron carriers ATP 12% of the time 88% of the time Cellular Respiration Amino acids Fatty acids Glucose Pyruvate Acetyl-CoA Glycolysis Glycolysis Stage 1 ATP Stage 3 Stage 4 Pyruvate oxidation Citric acid cycle Citric acid cycle Oxidative phosphory-lation Electron transport chain ATP ATP CO2 CO2 H2O O2 Electron carriers Stages 1 & 2: Fuel molecules are partially broken down, producing ATP and electron carriers. Stage 2 Stage 3: Fuel molecules are fully broken down, producing ATP and electron carriers. Stage 4: Electron carriers donate electrons to the electron transport chain, leading to the synthesis of ATP. Cellular Respiration Stages Glycolysis (cytoplasm) Pyruvate oxidation (mitochondria) Citric acid cycle (mitochondria) Oxidative phosphorylation (mitochondria) C C C Pi ATP ATP NADH ATP ATP NADH ATP ATP C C C C C C C C C C C C C C C C C C C C C C O C O O– CH3 C O C O O– CH3 Cleavage phase Energy investment phase Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Energy liberation phase Step 2 Step 3 Step 1 Glucose Fructose-1,6- bisphosphate OH H H OH H OH O H H HO CH2OH H HO OH OH H H OCH2 P P O CH2O P CHOH C H O CH2O Pi Two molecules of pyruvate P CHOH H O C CH2O Two molecules of glyceraldehyde- 3-phosphate Feedback inhibition by ATP ATP binds to an allosteric site on enzyme which catalyzes a step in glycolysis glycolysis animation At the End of Glycolysis 4 ATP – 2 ATP used during energy investment = 2 ATP (net gain) 2 NADH Draw a simple box on a sheet of paper to represent the entire process of glycolysis. Add arrows to indicate the inputs and outputs of glycolysis, labeling each one (for example, glucose). Use open arrows to indicate energy management molecules (e.g., ATP, NAD+). Use closed arrows to indicate inputs and outputs other than ATP and electron carriers. Which labeled arrow represents glucose? Which labeled arrow represents CO2? Which labeled arrow could represent NAD+? Cellular Respiration Stages Glycolysis (cytoplasm) Pyruvate oxidation (mitochondria) Citric acid cycle (mitochondria) Oxidative phosphorylation (mitochondria) Outer membrane Intermembrane space Inner membrane Matrix The space inside the inner membrane is the mitochondrial matrix. The space between the inner and outer membranes is the intermembrane space. Mitochondria Cytosol Intermembrane space Matrix Pyruvate NAD+ NADH + H+ Acetyl-CoA Coenzyme A CO2 Amino acids Fatty acids Glucose Glycolysis Pyruvate Acetyl-CoA Citric acid cycle Electron carriers Electron transport chain ATP CO2 H2O O2 ATP ATP CO2 Pyruvate Oxidation Cytosol Intermembrane space Matrix Pyruvate NAD+ NADH + H+ Acetyl-CoA Coenzyme A CO2 Pyruvate Oxidation Draw a simple box on a sheet of paper to represent the process of pyruvate oxidation. Add arrows to indicate the inputs and outputs, labeling each one. Show ATP and electron carriers only in their high-energy state. Do not include coenzyme A. Use open arrows to indicate energy management molecules (e.g. ATP, NAD+). Use closed arrows to indicate inputs and outputs other than ATP and electron carriers. Which labeled arrow could represent NADH? Which labeled arrow could represent ATP? Which labeled arrow could represent CO2? Which labeled arrow could represent acetyl-CoA? b a d e (none) pyruvate oxidation Cellular Respiration Stages Glycolysis (cytoplasm) Pyruvate oxidation (mitochondria) Citric acid cycle (mitochondria) Oxidative phosphorylation (mitochondria) http://chemwiki.ucdavis.edu/Biological_Chemistry/Metabolism/Kreb's_Cycle Organic Molecules from the Citric Acid Cycle Sugars Alanine Lipids Acetate Pyruvate Acetyl-CoA Other amino acids, pyrimidines Aspartate Oxaloacetate Citrate Purines Other amino acids Glutamate a-Ketoglutarate Succinyl-CoA Citric acid cycle Heme, chlorophyll Draw a simple box on a sheet of paper to represent the citric acid cycle. Add arrows to indicate the inputs and outputs, labeling each one. Show ATP and electron carriers only in their high energy state. Do not include coenzyme A. Use open arrows to indicate energy management molecules. Use closed arrows to indicate inputs and outputs other than ATP and electron carriers. Which labeled arrow could represent acetyl-CoA? Which labeled arrow could represent CO2? Which labeled arrow could represent NADH? Cellular Respiration Stages Glycolysis (cytoplasm) Pyruvate oxidation (mitochondria) Citric acid cycle (mitochondria) Oxidative phosphorylation (mitochondria) Electron Transport Chain Intermembrane space Complex IV Complex III Complex I e- e- e- e- e- ATP synthase NADH NAD+ FADH2 FAD H+ 2H+ H+ 4 H+ H+ H+ H+ H+ H+ H+ Cytochrome c CoQ CoQ O2 2 H2O ADP ATP + Pi + + H+ H+ Complex II The electron transport chain in cellular respiration Mitochondrial matrix Inter membrane Electron Transport Chain Complex III Complex I Complex II ATP synthase H+ H+ H+ H+ H+ H+ H+ H+ H+ Cytochrome c CoQ CoQ ADP ATP + Pi ATP synthase uses the electrochemical proton gradient to drive the synthesis of ATP. The transport of electrons in complexes I, III, and IV is coupled with the transport of protons across the inner membrane, from the mitochondrial matrix to the intermembrane space. Proton transport and ATP synthesis Complex IV Electron Transport Chain Complex III Complex I Complex II ATP synthase H+ H+ H+ H+ H+ H+ H+ H+ H+ Cytochrome c CoQ CoQ ADP ATP + Pi ATP synthase uses the electrochemical proton gradient to drive the synthesis of ATP. The transport of electrons in complexes I, III, and IV is coupled with the transport of protons across the inner membrane, from the mitochondrial matrix to the intermembrane space. Proton transport and ATP synthesis Complex IV Matrix ADP ATP + Pi F1 F0 H+ Intermembrane space The F1 subunit then uses this rotational energy to catalyze the synthesis of ATP. The F0 subunit forms a channel that rotates as protons pass through it. ATP synthase is a molecular machine that is composed of two subunits, F0 and F1. 2 1 ATP Synthase https://www.youtube.com/watch?v=PjdPTY1wHdQ The Flow of Energy in Cellular Respiration Inner mitochondrial membrane Outer mitochondrial membrane Intermembrane space ATP generated Electron carriers produced NADH FADH2 Cell membrane Mitochondrial matrix NADH NADH ATP ATP ATP ATP 2 2 28 Total 32 2 2 6 2 Glucose Glycolysis Pyruvate Pyruvate oxidation Acetyl CoA Citric acid cycle Electron transport chain (ETC) and oxidative phosphorylation Draw four boxes on a sheet of paper, as shown below, and let these represent the stages of aerobic cellular respiration. Label the boxes, then add arrows to indicate the inputs and outputs, labeling each one. Show ATP and electron carriers only in their high-energy state. Use open arrows to indicate energy management molecules. Use closed arrows to indicate inputs and outputs other than ATP and electron carriers. Working with your neighbors, complete the diagram. Which arrow in the figure represents glucose? Which arrow in the figure represents water ? Which arrows in the figure represent CO2 ? 1 and 3 2, 4, and 5 2 and 4 1, 3, and 6 Which arrows in the figure represent ATP generated by substrate-level phosphorylation ? 1 and 3 2, 4, and 5 2 and 4 1, 3, and 6 Draw four boxes on a sheet of paper, as shown below, and let these represent the stages of aerobic cellular respiration. Label the boxes, then add arrows to indicate the inputs and outputs, labeling each one. Show ATP and electron carriers only in their high-energy state. Use open arrows to indicate ATP and electron carriers. Use closed arrows to indicate inputs and outputs other than ATP and electron carriers. Working with your neighbors, complete the diagram. In the diagram you already completed, the energy management molecules, ATP and electron carriers were in their high-energy state (NADH, ATP). Add dashed arrows to your diagram to indicate what happens to these energy management molecules in their low-energy state (NAD+, ADP, etc.). Which dashed arrow could represent FAD? Which dashed arrow could represent ADP? Which dashed arrow could represent NAD+?