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Chapter 9: Overview of Energy. Respiration vs Breathing. Photosynthesis : (Net Reaction ). Respiration : ( Net Reaction) AEROBIC CONDITIONS ( O 2 needed) In both reactions, there is a HYDROGEN and CARBON pathway
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Respiration: (Net Reaction) AEROBIC CONDITIONS (O2 needed) • In both reactions, there is a HYDROGEN and CARBON pathway • Photosynthesis-- Joins the hydrogen and oxygen pathway to form glucose • Respiration-- Separates these 2 pathways forming H2O and CO2
Aerobic Cell Respiration • Complete oxidation of 1 glucose molecule • Includes 4 major sets of reactions NOTE:Parts 2, 3, 4 occur in mitochondria ofaerobic cells only Part 4 occurs simultaneously with Parts 1, 2, 3 in aerobic cells
Review of Electron Carriers a. NAD + 2H + 2e- NADH + H+ b. FAD + 2H + 2e- FADH2 Bring e- to ETC of inner mitochodrial membrane
Fermentation • Aka Anaerobic Respiration • Catabolic process that partially breaks down sugars without the use of oxygen • Function of fermentation is to make ATP
Alcoholic Fermentation PGAL Pyruvic acid PGAL Pyruvic acid
Fermentation cont. Fermentation Via:
Alcoholic Fermentation Glycolysis followed by: pyruvic acid + NADH 2 alcohol + 2 CO2 + NAD+ Pyruvic Acids (Alcohol)
Lactic Acid Fermentation Glycolysis followed by: pyruvic acid + NADH 2 lactic acid + NAD+ Pyruvic Acids (Lactic Acid)
Glycolysis • Splitting of 1 glucose molecule into 2 molecules of pyruvic acid • Can occur aerobically or anaerobically
Glucose ATP made by process called SUBSTRATE- LEVEL PHOSPHORYLATION: transfer of phosphate group from a substrate (reactant) molecule to ADP ATP PGAL Pyruvic Acid
Respiration (4 Major Reactions) • Glycolysis (in cytoplasm) • Splitting of 1 molecule of glucose into 2 molecules of pyruvicacid • Can occur in aerobic or anaerobic conditions
Glucose PGAL Pyruvic Acid
Respiration (4 Major Reactions) cont. 2) Pyruvic Acid Oxidation: Aerobic (in matrix)
The Oxidation of Pyruvate to form Acetyl CoA for Entry Into the Krebs Cycle
Kreb’s Cycle Pyruvic Acid Oxidation
Respiration (4 Major Reactions) cont. 3) Kreb’sCycle/ Citric Aid Cycle (in matrix)
Kreb’s Cycle Pyruvic Acid Oxidation
Citric Acid Oxaloacetic Acid
Oxidative Phosphorylation High [H+] Low pH Low [H+] High pH
3 Methods of ATP Synthesis • Photosynthetic Phosphorylation • Process of making ATP (~P) with light energy using electrons from hydrogen and chlorophyll • Occurs during PSII • On thylakoid membranes- in grana within chloroplast • Need enzyme (ATP synthetase & proton pumps)- chemiosmosis • Has ETC-- Electron Transport Chain-- PSII and PSI
Photosynthetic Phosphorylation 4e- 4e- 4e- 4H+
3 Methods of ATP Synthesis cont. 2) Substrate Phosphorylation • Process of making ATP by rearrangement of bonds of substrates during glycolysis or Krebs Cycle (No energy added!) • Glycolysis (in cytoplasm) • Occurs in aerobic and anaerobic conditions • No enzyme (ATP synthetase & proton pump) • No ETC-- no H2O made
3 Methods of ATP Synthesis cont. • Krebs Cycle(in mitochondrion) • Occurs only under aerobic conditions • No enzyme (ATP synthetase & proton pump) • No ETC-- no H2O made
3 Methods of ATP Synthesis cont. 3) Oxidative Phosphorylation • Process of making ATP (~) from energy released from hydrogen electrons (e-) as they are carried to O2 by coenzymes via the ETC or respiratory chain • Occurs only under aerobic conditions • Occurs only inside mitochondria (on cristae membranes)
Oxidative Phosphorylation cont. • Needs enzyme (ATP synthetase + proton pump + ATP transport protein) • Needs ETC or respiratory chain • Final electron/ hydrogen acceptor is oxygen • H2O is made
Conversions: • NADH (produced in the cytoplasm) produces 2 ATP by the ETC b. NADH (produced in the mitochondria) produces 3 ATP by the ETC c. FADH2 (adds its electrons to the ETC at a lower level than NADH) so it produces 2 ATP
Net Energy Production from Aerobic Respiration 1. Glycolysis: 2 ATP 2. Krebs Cycle: 2 ATP 3. Electron Transport Phosphorylation: 32 ATP a. Glycolysis: net gain/ 2 NADH (x 2) = 4 ATP b. Pyruvate Acetyl CoA: 2 NADH (x 3) = 6 ATP c. Krebs Cycle: 6 NADH (x 3) = 18 ATP 2 FADH2 (x 2) = 4 ATP GRAND TOTAL: 36 ATP!!!