2/10 Daily Catalyst Pg. 81 ETC 1. Compare and contrast glycolysis and citric acid cycle. 2. Describe substrate-level phosphorylation. 3. What are the reduced forms of the electron shuttles?

2/10 Daily Catalyst Pg. 81 ETC 1. Compare and contrast glycolysis and citric acid cycle. Both are a part of cellular respiration, produce 2 ATP, and 2 NADH’s. Glycolysis produces pyruvate. CAC produces 2 CO2 and 1 FADH2. 2. Describe substrate-level phosphorylation. Transfer of a phosphate group from a substrate to an ADP molecule. 3. What are the reduced forms of the electron shuttles? NADH and FADH2

2/10 Class Business Pg. 81 ETC Quiz #20 (mini-test) on Friday Energy, glycolysis, CAC, and the ETC Review packet over Mardi Gras Break Tutoring available Study sheets Due February 2/27

2/10 Agenda Pg. 81 ETC Daily Catalyst Class Business CAC Review ETC notes Quiz #19 Glycolysis and CAC

CAC Review Location? Reactants? Products? Electron Shuttles? ATP Production?

2/10 Reading Quiz Name: _______________ Date: 2/10 Score: _____/4 1. What two components link glycolysis and the CAC to the ETC? 2. Where does the ETC occur? 3. Who is the final electron acceptor? 4. Who has more energy NADH or FADH2?

Concept 9.4: During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis Key Point #1: The electron transport chain (ETC) occurs in the inner membrane of the mitochondria. The folding of the membrane =cristae increase surface area Remember the drying towel?? Multiple chains in 1 mitochondria

The electron shuttles Their time to shine! Key Point #2: NADH and FADH2 Electron shuttles! Shuttle electrons to the inner membrane of the mitochondria NADH: 2 from G and 8 CAC FADH2: 2 from CAC Electrons will power ATP synthase (an enzyme) oxidative phosphorylation

Key Point #3: ETC- Proteins 1. NADH delivers electrons to complex 1 2. Electrons will be passed from complex 1 to complex IV (oxidation and reduction!) 3. FADH2 delivers electrons to complex 2 4. Complex IV passes ALL electrons to Oxygen 5. Oxygen forms H2O

Key Point #4: Oxygen is the final electron acceptor Electrons are passed to oxygen, forming water H2O O2 NADH FADH2 FMN Fe•S O FAD Cyt b Cyt c1 Cyt c Cyt a Cyt a3 2 H + + 12 I II III IV Multiprotein complexes 10 20 30 40 50 Free energy (G) relative to O2 (kcl/mol) Figure 9.13

Electrons from FADH2 are added Key Point #5: Electrons from FADH2 are less energetic . They will produce 1/3 LESS energy!

Chemiosmosis: The Energy-Coupling Mechanism INTERMEMBRANE SPACE H+ P i + ADP ATP A rotor within the membrane spins clockwise when H+ flows past it down the H+ gradient. A stator anchored in the membrane holds the knob stationary. A rod (for “stalk”) extending into the knob also spins, activating catalytic sites in the knob. Three catalytic sites in the stationary knob join inorganic Phosphate to ADP to make ATP. MITOCHONDRIAL MATRIX Figure 9.14 Key Point #6: ATP synthase Is the enzyme that actually makes ATP

Chemiosmosis Key Point #7: Chemiosmosis Is an energy-coupling mechanism that uses energy in the form of a H+ gradient across a membrane to drive cellular work Hydrogen's are released with the electrons NADH NAD+ Release a electron and hydrogen

Key Point #8: Electron transfer from NADH and FADH2 causes protein complexes to pump H+ from the mitochondrial matrix to the inter membrane space

The resulting H+ gradient Stores potential energy! energy Drives chemiosmosis in ATP synthase Is referred to as a proton-motive force

Electron transport chain Oxidative phosphorylation Chemiosmosis and the electron transport chain Oxidative phosphorylation. electron transport and chemiosmosis Glycolysis ATP Inner Mitochondrial membrane H+ P i Protein complex of electron carners Cyt c I II III IV (Carrying electrons from, food) NADH+ FADH2 NAD+ FAD+ 2 H+ + 1/2 O2 H2O ADP + Electron transport chain Electron transport and pumping of protons (H+), which create an H+ gradient across the membrane Chemiosmosis ATP synthesis powered by the flow Of H+ back across the membrane synthase Q Oxidative phosphorylation Intermembrane space mitochondrial matrix Figure 9.15

An Accounting of ATP Production by Cellular Respiration During respiration, most energy flows in this sequence Glucose to NADH to electron transport chain to proton-motive force to ATP

There are three main processes in this metabolic enterprise Electron shuttles span membrane CYTOSOL 2 NADH 2 FADH2 6 NADH Glycolysis Glucose 2 Pyruvate Acetyl CoA Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis MITOCHONDRION by substrate-level phosphorylation by oxidative phosphorylation, depending on which shuttle transports electrons from NADH in cytosol Maximum per glucose: About 36 or 38 ATP + 2 ATP + about 32 or 34 ATP or Figure 9.16

About 40% of the energy in a glucose molecule Is transferred to ATP during cellular respiration, making approximately 34 ATP Key Point #9: ~34 ATP molecules are made

Name: ______________________ Date: 2/10 Quiz #19 Score: ________/20 1. Where does glycolysis occur? 2. What is the reactant of glycolysis? 3. How much ATP is produced in glycolysis TOTAL? Yield? 4. Where does the NADH go after glycolysis? 5. Where does the citric acid cycle occur? 6. Why must pyruvate be converted in acetyl CoA? 7. What molecule is essential for the CAC to occur? 8. Where do NADH and FADH2 go after the CAC? 9. How much CO2 is produced in the CAC? 10. How does glycolysis and the CAC produce ATP? 11. Is NADH and FADH2 the reduced or oxidized form? 12.