AP Biology Daily Warm-up Friday, October 10 th Describe the Kreb’s Cycle and oxidative phosphorylation. How many ATP are produced in each? HW: -Read 7.5 and finish cell respiration project Turn in: -Nothing

AP Biology Today’s Task  Create a representation of cellular respiration in your own words  Prezi  Comic strip  Story  15 points  Need glycolysis, Kreb’s Cycle, oxidative phosphorylation and their details.

AP Biology Peep video Bioflix video on cell respiration Cell respiration video v=3aZrkdzrd04

AP Biology Cellular Respiration and Fermentation

AP Biology Remember energy coupling?

AP Biology Yielding Energy  Catabolic processes in the cell  Anaerobic respiration  Aerobic respiration  Both of these comprise cellular respiration

AP Biology How do we harvest energy from fuels?  Digest large molecules into smaller ones  break bonds & move electrons from one molecule to another  as electrons move they “carry energy” with them e-e- ++ e-e- +– loses e-gains e-oxidizedreduced oxidationreduction redox e-e-

AP Biology How do we move electrons in biology?  Moving electrons in living systems  electrons cannot move alone in cells  electrons move as part of H atom p e + H + H +– loses e-gains e-oxidizedreduced oxidationreduction C 6 H 12 O 6 6O 2 6CO 2 6H 2 OATP  +++ oxidation reduction H e-e-

AP Biology Oxidation & reduction  Oxidation  adding O  removing H  loss of electrons  releases energy  exergonic  Reduction  removing O  adding H  gain of electrons  stores energy  endergonic C 6 H 12 O 6 6O 2 6CO 2 6H 2 OATP  +++ oxidation reduction

AP Biology

Moving electrons in respiration  Electron carriers move electrons by shuttling H atoms around  NAD +  NADH (reduced)  FAD +2  FADH 2 (reduced) + H reduction oxidation P O–O– O–O– O –O–O P O–O– O–O– O –O–O C C O NH 2 N+N+ H adenine ribose sugar phosphates NAD + nicotinamide Vitamin B3 niacin P O–O– O–O– O –O–O P O–O– O–O– O –O–O C C O NH 2 N+N+ H NADH carries electrons as a reduced molecule reducing power! How efficient! Build once, use many ways H like $$ in the bank

AP Biology Metabolism is tightly controlled

AP Biology Overview of Cellular Respiration  3 metabolic stages  Anaerobic respiration 1. Glycolysis  respiration without O 2  in cytosol  Aerobic respiration  respiration using O 2  in mitochondria 2. Krebs cycle 3. Electron transport chain C 6 H 12 O 6 6O 2 ATP6H 2 O6CO 2  +++ (+ heat )

AP Biology Step 1: Glycolysis  Glucose (6C) is cleaved into 2 molecules of pyruvate (3C)  Requires 2 ATP but produces 4 ATP  2 NAD+ are reduced to 2 NADH

AP Biology

Glycolysis and Evolution  Core process shared by all domains

AP Biology

Next Step  Anaerobic conditions- Fermentation  Makes 2 ATP  Aerobic conditions-  Citric Acid Cycle aka Kreb’s Cycle

AP Biology Step II: Citric Acid Cycle  Inner membrane of mitochondrion  Pyruvate becomes acetyl CoA

AP Biology

Step III: Oxidative Phosphorylation  2 steps  Electron Transport Chain  Transfer of electrons  Proteins embedded in membrane  Last transfer is to oxygen  No ATP  Chemiosmosis  ATP synthase

AP Biology

Fermentation  Anaerobic respiration  Electron transport chain does not use oxygen  Fermentation  Extension of glycolysis  Must recycle NADH back to NAD+  Done by transferring electrons to pyruvate (end product)

AP Biology Two Types of Fermentation  Alcohol Fermentation  Pyruvate converted to ethyl alcohol  CO2 produced  Bacteria and yeast  Lactic acid Fermentation  Pyruvate reduced directly by NADH to form lactic acid  Fungi and bacteria  Cheese  Human muscle cells…