4/28 Daily Catalyst CR Review 1. Which metabolic process is common to both aerobic cellular respiration and alcoholic fermentation? A) Glycolysis B) Krebs cycle C) Electron transport chain D) Production of proton gradient 2. During which cellular process listed to the right is ATP formed via substrate-level phosphorylation? l. Glycolysis II. Krebs Cycle III. Fermentation A) I only B) I and II only C) I and III only D) I, II and III  

Math review-Mrs. Ireland 4/21 Ecology Erica 4/22 Evolution John Monday Tuesday Wednesday Thursday Friday 4/20 Math review-Mrs. Ireland 4/21 Ecology Erica 4/22 Evolution John Daquine 4/23 Transport Daniel 4/24 Cells-organelles Tiana Tiffany 4/27 Photosynthesis Quinshelle 4/28 Cellular respiration 4/29 DNA/RNA Bristin 4/30 Genetics/pedigree/punnett squares Tiffany Kiandria 5/1 Mitosis/meiosis Kordell 5/4 Rep/trans/transcript James, Joe, Paul 5/5 5/6 5/7 5/8 5/11 AP Test Day! 5/12 5/13 Pig Dissection 5/14 5/15 Dissection Presentation Class review questions Individual review questions HW or WS acceptable!

ATP H+ H+ H+ H+ H+ H+ ADP H+ P thylakoid membrane thylakoid space stroma ATP synthase e- NADPH NADP+ e- Photosystem I (P700) Photosystem II (P680) 5000 e- 4999 e- 5000 e- 5000 e- 5000 e- 4999 e- This “animation” walks through the steps of noncyclic electron flow, as outlined on the previous 3 slides. The “5000 e-” is meant for illustrative purposes only; no matter how many electrons were contained in photosystems II and I, if there was no way to replace those electrons, eventually the number of electrons would be 0. If that were to occur, there would no electrons to be excited by light, and the light reactions would grind to a halt. The electron that was “excited away” from photosystem I is replaced by the electron that was “excited away” from photosystem II; photosystem II’s lost electron is replaced through photolysis – the splitting of water – which releases ½ a molecule of O2 as a byproduct. This is where the oxygen comes from that is produced during photosynthesis, and is why autotrophs need water to perform photosynthesis! The oxygen is released through the stomata. The electron that was excited away from Photosystem I ends up reducing [adding an electron to] NADP+ to form NADPH, an important electron carrier that is needed in the Calvin Cycle. Make sure to point out to students the coupled reactions that occur; as the electron travels down the electron transport chain, its “lost energy” is used to pump protons from the stroma to the thylakoid space to build a concentration gradient. Then, as those protons diffuse back across the thylakoid membrane through ATP synthase to achieve equilibrium, they cause ATP synthase to spin (like a turbine), which forces ADP and the phosphate group together, forming ATP. Don’t forget to point out that the membrane is key here! If there was no thylakoid membrane (or if its integrity was disrupted and therefore “leaky”), it would be impossible to build this concentration gradient – not to mention that the cytochromes, photosystems, and ATP synthase would not exist/be functional! Make sure to make the connection with “osmosis” when discussing “chemiosmosis;” for students who understand the idea of the movement of molecules from an area of high concentration to an area of low concentration (as in osmosis), discuss the idea that this is essentially the same process, just with protons (H+) instead of water molecules. H+ H+ H H H+ O H+ H+ H+ H+ e- H+ O H+ (2 H+ & ½ O2)

Phase 2: The Calvin Cycle CO2 Rubisco ATP RuBP NADPH - This simple schematic diagram gives a basic overview of what occurs during the Calvin Cycle. Carbon dioxide enters the cycle from the atmosphere and is joined to RuBP by Rubisco. NADPH and ATP are used to “turn” the cycle, and organic compounds (such as G3P/PGAL) are produced. NADP+ ADP P ORGANIC COMPOUND

Oxidative phosphorylation: electron transport and chemiosmosis An overview of cellular respiration Figure 9.6 Electrons carried via NADH Glycolsis Glucose Pyruvate ATP Substrate-level phosphorylation Electrons carried via NADH and FADH2 Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis Oxidative Mitochondrion Cytosol

Energy investment phase Glycolysis Citric acid cycle Oxidative phosphorylation ATP 2 ATP 4 ATP used formed Glucose 2 ATP + 2 P 4 ADP + 4 2 NAD+ + 4 e- + 4 H + 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Energy investment phase Energy payoff phase 4 ATP formed – 2 ATP used 2 NAD+ + 4 e– + 4 H + Figure 9.8 Key Point #2: Glycolysis consists of two major phases Energy investment phase Energy payoff phase Key Point #3: Glycolysis begins with glucose

A closer look at the energy investment phase

2 ATP molecules are invested. Need money to make money! Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate H OH HO CH2OH O P CH2O CH2 C CHOH ATP ADP Hexokinase Glucose Glucose-6-phosphate Fructose-6-phosphate Phosphoglucoisomerase Phosphofructokinase Fructose- 1, 6-bisphosphate Aldolase Isomerase Glycolysis 1 2 3 4 5 Oxidative phosphorylation Citric acid cycle Figure 9.9 A 2 ATP molecules are invested. Need money to make money!

A closer look at the energy payoff phase

1, 3-Bisphosphoglycerate 2 NAD+ NADH 2 + 2 H+ Triose phosphate dehydrogenase P i P C CHOH O CH2 O– 1, 3-Bisphosphoglycerate 2 ADP 2 ATP Phosphoglycerokinase 3-Phosphoglycerate Phosphoglyceromutase CH2OH H 2-Phosphoglycerate 2 H2O Enolase Phosphoenolpyruvate Pyruvate kinase CH3 6 8 7 9 10 Pyruvate Figure 9.8 B 4 ATP molecules are produced. 4- 2(energy investment phase)= 2 ATP left!

Key Point #4: Glycolysis ends with 2 pyruvate molecules

1, 3-Bisphosphoglycerate 2 NAD+ NADH 2 + 2 H+ Triose phosphate dehydrogenase P i P C CHOH O CH2 O– 1, 3-Bisphosphoglycerate 2 ADP 2 ATP Phosphoglycerokinase 3-Phosphoglycerate Phosphoglyceromutase CH2OH H 2-Phosphoglycerate 2 H2O Enolase Phosphoenolpyruvate Pyruvate kinase CH3 6 8 7 9 10 Pyruvate Figure 9.8 B

Substrate-level phosphorylation Key Point #6: Substrate-level phosphorylation: Enzymes transfer a phosphate group from a substrate to ADP ATP Occurs in glycolysis and the citric acid cycle Figure 9.7 Enzyme ATP ADP Product Substrate P +

Before the citric acid cycle can begin, Pyruvate must first be converted into Acetyl CoA Key Point #3: Pyruvate is converted into Acetyl CoA. 1 CO2 and 1 NADH are created. (2) pyruvates 2 Acetyl CoA’s = 2 CO2 and 2 NADH CYTOSOL MITOCHONDRION NADH + H+ NAD+ 2 3 1 CO2 Coenzyme A Pyruvate Acetyle CoA S CoA C CH3 O Transport protein O– Figure 9.10

An overview of the citric acid cycle ATP 2 CO2 3 NAD+ 3 NADH + 3 H+ ADP + P i FAD FADH2 Citric acid cycle CoA Acetyle CoA NADH CO2 Pyruvate (from glycolysis, 2 molecules per glucose) Glycolysis Oxidative phosphorylation Figure 9.11 The CAC also known as the Krebs Cycle for the scientist that solidified the steps of the cycle, is an eight series cycle that occurs in the matrix of the mitochondria. This is a cycle that will only occur in the presence of oxygen. Pyruvate from the glycolysis step, will need to converted into Acetyl CoA before CAC can begin. During this conversion which occurs in the intermembrane space, both pyruvates are converted into Acetyl CoA’s and a molecule of CO2 is produced per pyruvate and an NADH is produced per pyruvate. Thus far, we have seen CO2 produced as a waste product and released!

A closer look at the citric acid cycle Acetyl CoA NADH Oxaloacetate Citrate Malate Fumarate Succinate Succinyl CoA a-Ketoglutarate Isocitrate Citric acid cycle S SH FADH2 FAD GTP GDP NAD+ ADP P i CO2 H2O + H+ C CH3 O COO– CH2 HO HC CH 1 2 3 4 5 6 7 8 Glycolysis Oxidative phosphorylation ATP Figure 9.12 X2 Key Point #4: FADH2 Coenzyme Electron shuttle Not as energetic as NADH Figure 9.12 We do not need to memorize EVERY step of the CAC, but we can take notice that first this is a cycle! It goes round and round! Also, this eight step process would not be possible without enzymes at every step speeding up conversions! This step of cellular respiration is NOT a huge maker of ATP like glycolysis, but we do see some ATP made here and production of NADH and FADH2 which will make a lot of ATP in the next step. The cycle will occur twice since there are two Acetyl CoA molecules.

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

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