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This lesson delves into Glycolysis II and the oxidation of pyruvate, crucial stages in cellular respiration. Beginning with glucose (C6H12O6), the processes yield 6 CO2, 6 H2O, and 36 ATP through a series of oxidation reactions. Glycolysis II converts G3P into pyruvate via five steps, generating ATP and NADH. The subsequent pyruvate oxidation transforms pyruvate into acetyl-CoA in three steps, enabling further energy extraction from glucose. Understanding these pathways is essential for grasping how cells harvest energy.
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Last class... Intro to cellular respiration C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP * A series of oxidizing reactions converts the energy stored in C-C bonds of glucose to form ATP molecules
Last class... • 2 reactions: • 1. Substrate-level Phosphorylation • - Directly produces ATP from ADP + Pi ATP • 2. Oxidative Phosphorylation • Indirectly produces ATP through the use of electron carriers • NAD+ + 2e + 1p NADH + H+ • FAD + 2e + 2p FADH2
Last class... • 4 steps in the process of cellular respiration: • Glycolysis • Pyruvate Oxidation • Krebs Cycle • ETC/Chemiosmosis
Last class... Glycolysis I
Today... *In Glycolysis I, we have broken glucose down into two 3-carbon molecules called G3P (Glyceraldehyde-3-phosphate) * We need to transform those molecules into more usable forms *In Glycolysis II, G3P is converted to PYRUVATE! ** Pyruvate also has 3-carbons * IMP: we will only talk about 1 set of reactions from now on, although it happens twice (for each G3P molecule)
Glycolysis II Step 1: G3P picks up a Pi and is reduced by NAD+ to form 1,3 – BISPHOSPHOGLYCERATE[BPG] *Note: NAD+ removes a H (2 e, 1p) from G3P to form NADH + H +
Glycolysis II Step 2: BPG loses a phosphate group to form 3-PHOSPHOGLYCERATE[3PG] *Note: The loss of Pi from BPG from is used to form ATP ADP + Pi ATP
Glycolysis II Step 3: 3PG rearranges to form 2-PHOSPHOGLYCERATE[2PG] *Isomerization reaction!
Glycolysis II Step 4: 2PG loses 2 H’s and 1 Oxygen as water to form PHOSPHO-ENOL-PYRUVATE[PEP]
Glycolysis II Step 5: PEP loses a phosphate group, Pi , to form PYRUVATE *Note: The loss of Pi from PEP from is used to form ATP ADP + Pi ATP
Glycolysis - SUMMARY • We have converted glucose into two 3-carbon molecules, PYRUVATE that will be further converted • GLYCOLYSIS ENERGY TALLY
Question of the Day • Can our thoughts after the world around us? • Word of the Day • NOETIC SCIENCE
PYRUVATE OXIDATION *TRANSITION REACTION*
PYRUVATE OXIDATION * Now that we have produced two molecules of PYRUVATE, we need to break it down even further to obtain all the energy possible from the C-C bonds in glucose. * Glycolysis occurred in the CYTOPLASM, * Pyruvate oxidation transports the molecules across the inner membrane into the mitochondrial matrix * There are 3 steps in one transition reaction
PYRUVATE OXIDATION Steps: 1. CO2 is removed from PYRUVATE to form an acetyl group 2. NAD+removes 2 e + 1p from pyruvate to form NADH + H+ 3. CoA combines to the remaining molecule to form ACETYL-CoA*Co-enzyme A is used to shuttle the acetyl group across the membrane
PYRUVATE OXIDATION - SUMMARY • Pyruvate, produced from glucose, is converted into a more useful form, ACETYL-CoA, that can be transported across the mitochondrial membrane • PYRUVATE OXIDATION ENERGY TALLY • TOTAL ENERGY TALLY
