AP Biology Cellular Respiration- Breaking the bonds of sugar to produce ATP ATP

AP Biology Cellular Respiration – makes ATP by breaking down sugars and other carbon-based molecules.  3 metabolic stages  Anaerobic respiration 1. Glycolysis - “Glucose Breaking”  Anaerobic respiration -respiration without O 2  Located in the cytoplasm  Produces a net of 2 ATP molecules/glucose  Aerobic respiration phase – respiration with O 2  2. Krebs cycle  Located in the mitochondria matrix  Produces 2 ATP/glucose  3. Electron transport chain  Located in the mitochondrial inner membrane  Produces ATP/glucose

AP Biology C 6 H 12 O 6 6O ATP 6H 2 O6CO 2  +++

AP Biology Mitochondria — Structure intermembrane space inner membrane outer membrane matrix cristae  Double membraned energy harvesting organelle  highly folded inner membrane increases surface area  Cristae  Matrix  inner fluid-filled space  enzymes  Found free in matrix & as well as membrane-bound What cells would have a lot of mitochondria?

AP Biology Glycolysis –anaerobic respiration  occurs in cytoplasm  Sugar is broken into two pyruvic acid molecules and releases 2 molecules of ATP/Glucose  Net gain of 2 ATP produced for every glucose 2x2x 6C3C glucose      pyruvate

AP Biology ATP 2 ADP 2 ATP 4 ADP 4 NAD + 2 2Pi2Pi 2 -2 ATPs release energy -Phosphate is added to another compound. -An electron moving down membranes, eventually bonding with NAD+. This gain of electrons attracts hydrogen ions, which bonds to NAD+, storing energy in the bonds of NADH -ADP gains the third phosphate, forming ATP. Energy is stored in the phosphate bonds.

AP Biology Step 1. Two ATP molecules are used to energize a glucose molecule. The glucose molecule is split into two three-carbon molecules. P P P P P 2 2 P P PP CCCCC C P P P P P CCCCC C PP CCC P CC C P CC C P CCC P

AP Biology Step 2. Energized electrons and hydrogen ions from the three-carbon molecules are transferred to molecules of NAD+, becoming NADH. A series of reactions converts the 3- carbon molecules to Acetyl Co-A which enters cellular respiration P P P P P P 2 2 P P PP P P P P P 2 2 P P P P P 2 2 NAD

AP Biology Glycolysis- The Song!

AP Biology If No Oxygen is present the pyruvate cannot enter the Kreb Cycle and goes into Fermentation instead.

AP Biology 2 Types of Fermentation  A. Alcoholic Fermentation – occurs in Plants & Bacteria  Produces NAD+, 2 ATP, and ethanol.  Used in the production of wines, cheeses, breads.

AP Biology B. Lactic Acid Fermentation – In Animals Produces NAD+ and Lactic acid Causes pain in the joints.

AP Biology Oxidation-Reduction Reaction…Redox! NAD+ e- & H+ Where does the Carbon go? Exhale! IV. STAGE 2: KREBS CYCLE – AEROBIC RESPIRATION a.Occurs in the mitochondrial matrix b.A process that breaks pyruvate through a series of reactions producing Electron Carrier compounds, ATP and carbon dioxide gas. c.Produces large quantities of electron carriers like NADH, and FADH2 that go to the Electron Transport Chain. Step 1. Pyruvate (from glycolysis) is broken down (loses a carbon). Step 2 Coenzyme A (CoA) bonds to the two-carbon molecule. This intermediate molecule ( Acetyl-CoA ) enter the Krebs cycle.

AP Biology CC C Where does the Carbon go? Exhale! + Coenzyme A (CoA) 3C Oxidation of Pyruvate NAD+ e- & H+ Acetyl Group CC Acetyl-CoA CC To the Krebs Cycle! Loss of CO 2 C Remember, this happens twice,once for each Pyruvate! 2 = 2 CO 2 = 2 NADH = 2 Acetyl CoA

AP Biology Step 3 Citric Acid is formed by bonding acetyl-coA to a four carbon molecule. Step 4: Citric acid is broken down by releasing a carbon, and a five-carbon molecule is made. Step 5. The five-carbon molecule is broken down. A four-carbon molecule is made. Step 6. The four-carbon molecule is rearranged. 2 ATPs are formed. Products from breakdown of one molecule of pyruvate: CO 2 given off as a waste product each time a carbon is broken off. 2 ATP 4 NADH goes to ETC 1 FADH 2 goes to ETC

AP Biology 4C6C4C 2C6C5C4C CO 2 citrate acetyl CoA Now for the Krebs Cycle -count the carbons! 3C pyruvate x2x2 oxidation of sugars This happens twice. One for each pyruvate molecule. CO 2

AP Biology 4C6C4C 2C6C5C4C CO 2 citrate acetyl CoA Now, count the electron carriers! 3C pyruvate Storing energy using electron carriers This happens twice for each pyruvate molecule x2x2 CO 2 NADH ATP FADH 2 2

AP Biology

So we fully oxidized glucose C 6 H 12 O 6  6CO 2 & ended up with all of 4 ATP! 2 from Glycolysis 2 from Krebs Cycle Whassup with this? What’s the point?

AP Biology What’s so important about electron carriers? H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP ADP + P i  Krebs cycle produces large quantities of electron carriers  8 NADH  2 FADH 2  go to Electron Transport Chain!

AP Biology STAGE 3: Electron Transport Chain  Takes place in the inner mitochondrial membrane  A process that uses high electron carriers from the Krebs cycle to generate ATP by oxidative phosphorylation.  Produces ATP molecules per molecule of glucose.  Step 1. H+ and e- are removed from NADH and FADH 2.  Step 2. Hydrogen ions are transported across the membrane.  Step 3. ADP is changed into ATP when hydrogen ions flow through ATP Synthase.  Step 4. Water is formed when oxygen picks up electrons and hydrogen ions.

AP Biology

Mitochondria 2H + +O2O intermembrane space inner membrane outer membrane matrixcristae H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ NAD + Q C NADH H 2 O H+H+ e–e– 2H + +O2O2 H+H+ H+H+ e–e– FADH NADH dehydrogenase cytochrome bc complex cytochrome c oxidase complex FAD e–e– ADP + P i TA-DA!! Moving electrons do the work! H+H+ H+H+ H+H+ P H+H+ O- H+H+ ATP H+H+ P P P P P P P H+H+ H+H+ O- H+H+ H+H+ H+H+

AP Biology H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ NAD + Q C NADH H 2 O H+H+ e–e– 2H + +O2O2 H+H+ H+H+ e–e– FADH NADH dehydrogenase cytochrome bc complex cytochrome c oxidase complex FAD e–e– ADP + P i TA-DA!! Moving electrons do the work! H+H+ H+H+ H+H+ Chemiosmosis powers the proton pump! P H+H+ O- H+H+ ATP H+H+ P P P P P P P H+H+ H+H+ O- H+H+ H+H+ H+H+  The diffusion of ions across a membrane  build up of proton gradient just so H+ could flow through ATP synthase enzyme to build ATP  The final electron acceptor is oxygen, which forms water.

AP Biology. SUMMARY - The products of cellular respiration – including glycolysis are:  CO2 from the Kreb’s Cycle and from the breakdown of pyruvate before the Krebs cycle  Water from the Electron Transport Chain  A net gain of up to ATP molecules for every glucose molecule – 2 ATP from glycolysis, 2 ATP from the Krebs cycle, and up to ATP from the electron transport chain. C 6 H 12 O 6 6O ATP 6H 2 O6CO 2  +++ Kreb’s Cycle Electron Transport Chain

AP Biology

A single cell uses about 10 million ATP molecules per second! If you are chasing prey for food, or being chased by a predator, it is probably higher…

AP Biology  ETC backs up  nothing to pull electrons down chain  NADH & FADH 2 can’t unload H  ATP production ceases  cells run out of energy  and you die! Taking it beyond…  What is the final electron acceptor in Electron Transport Chain? O2O2  So what happens if O 2 unavailable? NAD + Q C NADH H 2 O H+H+ e–e– 2H + +O2O2 H+H+ H+H+ e–e– FADH NADH dehydrogenase cytochrome bc complex cytochrome c oxidase complex FAD e–e–

AP Biology Xlo1W3Gvg&feature=related What happens when you run out of Oxygen! A single cell uses about 10 million ATP molecules per second –