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Glycolysis & Fermentation

Glycolysis & Fermentation. 7.1. ATP is the main energy currency of cells. Cellular respiration – process of making ATP by breaking down organic compounds

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Glycolysis & Fermentation

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  1. Glycolysis & Fermentation 7.1

  2. ATP is the main energy currency of cells Cellular respiration – process of making ATP by breaking down organic compounds • A catabolic, exergonic, oxygen (O2)requiring process that uses energyextracted from macromolecules (glucose) to produce energy (ATP)and water (H2O).

  3. glucose ATP Cellular respiration equation: byproduct C6H12O6 + 6O2 6CO2 + 6H2O + energy

  4. Who uses cellular respiration and • Where does it take place?

  5. Who undergoes cellular respiration? (eukaryotes) • Plants - Autotrophs: self-producers. • Animals - Heterotrophs: consumers.

  6. What are the Stages of Cellular Respiration? • Glycolysis • The Krebs Cycle • The Electron Transport Chain

  7. Inner membrane space Matrix Cristae Outer membrane Inner membrane Where? Mitochondria • Organelle where cellular respirationtakes place.

  8. Redox Reaction • Transfer of one or more electrons from one reactantto another. • Two types: 1. Oxidation 2. Reduction

  9. Oxidation glucose ATP Oxidation Reaction • The loss of electrons from a substance. • Or the gain of oxygen. C6H12O6 + 6O2 6CO2 + 6H2O + energy

  10. Reduction C6H12O6 + 6O2 6CO2 + 6H2O + energy glucose ATP Reduction Reaction • The gain of electrons to a substance. • Or the loss of oxygen. byproduct

  11. Breakdown of Cellular Respiration 1. Glycolysis (splitting of sugar) a. cytosol, just outside of mitochondria. 2. Grooming Phase a. migration from cytosol to matrix.

  12. Breakdown of Cellular Respiration 3. Krebs Cycle (Citric Acid Cycle) a. mitochondrial matrix 4. Electron Transport Chain (ETC) and Oxidative Phosphorylation a. Also called Chemiosmosis b. inner mitochondrial membrane.

  13. GLYCOLYSIS • biochemical pathway, yields 2 ATP • Occurs in cytosol • Converts NAD+ oxidized to NADH to produce pyruvic acid then reduced to form lactic acid • With Oxygen > aerobic - additional ATP • Without Oxygen > anaerobic - fermentation yields NO additional ATP

  14. Glucose (6C) C-C-C-C-C-C 2ATP 2 ATP - used 0 ATP - produced 0 NADH - produced 2ADP + P C-C-C C-C-C Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) 1. Glycolysis A. Energy use Phase:

  15. Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) GAP GAP C-C-C C-C-C 4ADP + P 0 ATP - used 4 ATP - produced 2 NADH - produced 4ATP C-C-C C-C-C (PYR) (PYR) Pyruvate (2 - 3C) (PYR) 1. Glycolysis B. Energy Yielding Phase

  16. 1. Glycolysis • Total Net Yield 2 - 3C-Pyruvate (PYR) 2 - ATP (Substrate-level Phosphorylation) 2 - NADH

  17. Enzyme O- C=O C-O- CH2 Adenosine P P P Substrate ADP (PEP) O- C=O C=O CH2 Product (Pyruvate) Adenosine P P P ATP Substrate-Level Phosphorylation • ATP is formed when an enzyme transfers a phosphate groupfrom a substrate to ADP. Example: PEP to PYR

  18. Animation: • http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html

  19. RECALL • Redox – one reactant is oxidized while another is reduced • oxidized loses e- and becomes pos • reduced gains e- and becomes neg

  20. GYLCOLYSIS RECAP • glucose oxidized yields pyruvic acid • reactions take place in cytosol • NAD+ to NADH (electron acceptor) • Pyruvic acid yields 4 ATP but 2 used in process (so net yield is 2 ATP)

  21. Fermentation • fermentation is the formation of alcohol from sugar. • Occurs in cytosol when “NO Oxygen”is present (called anaerobic). • Remember: glycolysis is part of fermentation. • Two Types: 1. Lactic Acid (animal cells) 2. Alcohol (plant cells)

  22. Lactic acid fermentation • NADH oxidized to NAD+ e.g. Yogurt, cheese • *in muscle – not enough oxygen so switch to anaerobic respiration b/c oxygen is depleted which makes cytosol acidic so produces cramps

  23. 2ADP + 2 2ATP C C C C CC P 2NADH 2 NAD+ C C C C C C Glycolysis 2 Lactic acid 2 Pyruvic acid 2 NAD+ 2NADH Glucose Lactic Acid Fermentation • Animals (pain in muscle after a workout).

  24. Lactic Acid Fermentation • End Products: Lactic acid fermentation 2 - ATP (phosphorylation) 2 - Lactic Acids

  25. Alcoholic Fermentation • convert pyruvic to ethyl alcohol by removing CO2 e.g. bread, beer, wine - need enzymes in yeast

  26. 2ADP + 2 2ATP C C C C CC P 2NADH 2 NAD+ C C C C C Glycolysis 2 Ethanol 2 Pyruvic acid 2CO2 released 2 NAD+ 2NADH glucose Alcohol Fermentation • Plants and Fungi  beer and wine

  27. Alcohol Fermentation • End Products: 2 - ATP (phosphorylation) 2 - CO2 2 - Ethanol’s

  28. glycolysis is not efficient but unicellular organisms don’t need much energy to function • E.g. paramecium, ameoba • probably evolved early in history of life

  29. kilocalories – 1 kcal = 1000 cal

  30. How does the overall equation for aerobic respiration relate to its four stages? • http://w3.dwm.ks.edu.tw/bio/activelearner/07/ch7intro.html

  31. Aerobic Respiration 7.2

  32. Aerobic respiration • cellular respiration that requires oxygen • 2 major stages: Krebs cycle & electron transport chain

  33. STAGE 1 • Krebs cycle – biochemical pathway that breaks down acetyl CoA producing CO2, Hydrogen, & ATP • Aka = Citric Acid Cycle • Completes oxidation of glucose began in glycolysis • Takes place in/ mitochondrion unlike glycolysis that occurs in/ cytosol

  34. Pyruvic acid from glycolysis diffuses across membrane to Mitochondrial matrix & forms Acetyl coenzyme A (acetyl CoA)

  35. 5 Steps in Krebs cycle • Step 1 – produces citric acid • Step 2 – releases CO2 • Step 3 – releases CO2 • Step 4 – conversion of 4-carbon compound • Step 5 – 4-carbon compound converted back to oxaloacetic acid

  36. Citric acid - formed when acetyl CoA combines with Oxaloacetic acid • FAD - flavin adenine dinucleotide – like NAD+ b/c accepts electrons

  37. Each turn of citric acid cycle produces: • ATP, NADH, FADH2

  38. In glycolysis: 1 glucose produced 2 ATP which is same as Krebs cycle

  39. Stage 2: • Electron transport chain – occurs along inner membrane • Concentration gradient between 2 membranes drive chain • ATP synthase catalyzes ATP from ADP and phosphate ion known as chemiosmosis just like photosynthesis

  40. Efficiency of energy: • glycolysis = 2 ATP • Krebs = 2 ATP • E.T.C. = 34 ATP 38 ATP • but some is used to pump NADH across membrane so ~ 36 ATP

  41. summary of Cellular Respiration:http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookGlyc.html

  42. References • http://www.search.com/reference/Mitochondrion • http://images.google.com/imgres?imgurl=http://microbewiki.kenyon.edu/images/thumb/2/25/Mitochondria.gif/400px-Mitochondria.gif&imgrefurl=http://microbewiki.kenyon.edu/index.php/Mitochondria&h=311&w=400&sz=94&hl=en&start=107&um=1&tbnid=7oaJZwsF_GSTgM:&tbnh=96&tbnw=124&prev=/images%3Fq%3Dmitochondrial%2Bmatrix%26start%3D100%26ndsp%3D20%26svnum%3D10%26um%3D1%26hl%3Den%26rlz%3D1T4GGIC_enUS233US233%26sa%3DN • http://images.google.com/imgres?imgurl=http://wps.prenhall.com/wps/media/objects/486/498525/FG06_12FR.JPG&imgrefurl=http://wps.prenhall.com/esm_freeman_biosci_1/0,6452,498573-,00.html&h=268&w=550&sz=41&hl=en&start=17&um=1&tbnid=OG0HGNN3_pgRmM:&tbnh=65&tbnw=133&prev=/images%3Fq%3Dmitochondrial%2Bmatrix%26svnum%3D10%26um%3D1%26hl%3Den%26rlz%3D1T4GGIC_enUS233US233%26sa%3DG • http://www.estrellamountain.edu/faculty/farabee/biobk/BioBookGlyc.html • www.biologyjunction.com

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