1. Miss Tee Monday, March 22nd

2. Glycolysis Glycolysis in every living cell in every living cell break down of one glucose molecule (6- Carbon sugar) into (2) 3-Carbon sugar (pyruvate) break down of one glucose molecule (6- Carbon sugar) into (2) 3-Carbon sugar (pyruvate) Yield of ATP low Yield of ATP low Takes place in cytosol Takes place in cytosol Pyruvate Oxidation Pyruvate Oxidation Pyruvate transported to matrix Pyruvate transported to matrix Modified into acetyl CoA Modified into acetyl CoA Prepares molecule for further oxidation in Kreb’s cycle (S-bond unstable) Prepares molecule for further oxidation in Kreb’s cycle (S-bond unstable)

3. Sir Hans Krebs Sir Hans Krebs 1937, awarded Nobel Prize for discovery of cyclic series of enzymatic reactions in mitochondria 1937, awarded Nobel Prize for discovery of cyclic series of enzymatic reactions in mitochondria Def: cyclic series of enzymatic rxns that transfers energy from organic molecules to ATP, NADH, and FADH 2 and removes carbon atoms as CO 2 Def: cyclic series of enzymatic rxns that transfers energy from organic molecules to ATP, NADH, and FADH 2 and removes carbon atoms as CO 2 8 steps 8 steps

5. By the end: By the end: Original glucose molecule completely consumed Original glucose molecule completely consumed 6 carbon atoms leave as 6 CO2  waste 6 carbon atoms leave as 6 CO2  waste CCCCCC  CCC + CCC  CC + CC + CO2 + CO2  4 CO2 (glucose) (2 pyruvate) (2 acetyl CoA + 2 CO2) (4CO2) Energy stored in 2 ATP (1 ATP/acetyl CoA molecule) Energy stored in 2 ATP (1 ATP/acetyl CoA molecule) Where do you see substrate-level phosphorylation? Where do you see substrate-level phosphorylation? Step 5 Step 5

8. Electron transport chain Electron transport chain Consists of series of enzymes on IMM Consists of series of enzymes on IMM Electrons are released from NADH, FADH2 Electrons are released from NADH, FADH2 Enzymes arranged in increasing electronegativity Enzymes arranged in increasing electronegativity Alternating redox, gaining and losing 2 e- Alternating redox, gaining and losing 2 e- Electrons shuttle through ETC, occupying more stable positions Electrons shuttle through ETC, occupying more stable positions Oxygen: final electron acceptor Oxygen: final electron acceptor Strips 2 e- from enzyme complex + 2 H+ from matrix = H20 Strips 2 e- from enzyme complex + 2 H+ from matrix = H20

9. Free energy released used to actively transport protons (H+) through proton pumps Free energy released used to actively transport protons (H+) through proton pumps By creating a simple chemical gradient, specialized enzyme ATP Synthase is powered to phosphorylate ADP = ATP By creating a simple chemical gradient, specialized enzyme ATP Synthase is powered to phosphorylate ADP = ATP

11. NADH and FADH2 slightly different: NADH and FADH2 slightly different: FADH2 skips 1 st enzyme  transfers 2 e- directly to Q FADH2 skips 1 st enzyme  transfers 2 e- directly to Q FADH2 contributes 2e-  2 ATP FADH2 contributes 2e-  2 ATP NADH contributes 3e-  3 ATP NADH contributes 3e-  3 ATP What about cytosolic NADH from glycolysis? What about cytosolic NADH from glycolysis? Why are there many folds of the inner membrane? Why are there many folds of the inner membrane? Limiting factor NAD+ and FAD molecules Limiting factor NAD+ and FAD molecules

12. Converts chemical potential energy into electrochemical potential energy Converts chemical potential energy into electrochemical potential energy Like a charged battery: accumulation of charge on one side of an insulator Like a charged battery: accumulation of charge on one side of an insulator Creates electrochemical potential (voltage) Creates electrochemical potential (voltage) H+ unable to diffuse through phospholipid bilayer H+ unable to diffuse through phospholipid bilayer Forced through specialized proton channels coupled to ATP synthase Forced through specialized proton channels coupled to ATP synthase Reduces free energy of electrochemical gradient Reduces free energy of electrochemical gradient Drives ADP + Pi  ATP Drives ADP + Pi  ATP

13. Process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme Process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme

15. ATP transported via facilitated diffusion into cytosol, needed for active transport, movement, synthesis reactions ATP transported via facilitated diffusion into cytosol, needed for active transport, movement, synthesis reactions *Why do we need O 2 ? *Why do we need O 2 ? To survive, we need ATP from ETC/chemiosmosis To survive, we need ATP from ETC/chemiosmosis We need a maintenance of H+ reservoir We need a maintenance of H+ reservoir We need the flow of e- We need the flow of e- We need O 2 to “pull” electrons down the ETC (in their “energy-yielding fall”…like a skydiver) We need O 2 to “pull” electrons down the ETC (in their “energy-yielding fall”…like a skydiver)

16. Amount of energy consumed by an organism at a given time Amount of energy consumed by an organism at a given time BMR: basal metabolic rate BMR: basal metabolic rate minimum amount of energy required for organism survival minimum amount of energy required for organism survival Accounts for 60-70% energy consumed per day Accounts for 60-70% energy consumed per day When is an individual’s BMR greatest?? When is an individual’s BMR greatest??