Figure 2.18
Copyright © 2010 Pearson Education, Inc. Collision Theory The collision theory states that chemical reactions can occur when atoms, ions, and molecules collide Activation energy is the amount of energy needed for them to collide ‘hard’ enough to disrupt electronic configurations and produce a chemical reaction Reaction rate is the frequency of collisions with enough energy to bring about a reaction. Reaction rate can be increased by enzymes or by increasing temperature or pressure
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Figure 5.4a The Mechanism of Enzymatic Action
Copyright © 2010 Pearson Education, Inc. Figure 5.7a–b Enzyme Inhibitors: Competitive Inhibition
Copyright © 2010 Pearson Education, Inc. Enzyme Inhibitors: Competitive Inhibition Example-Sulfa drugs (sulfonamides) Discovered in the 1930s
Copyright © 2010 Pearson Education, Inc. Oxidation-Reduction Reactions Oxidation: Removal of electrons. The general process of electron donation to an electron acceptor is also referred to as oxidation even though the electron acceptor may not be oxygen. Reduction: Gain of electrons Redox reaction: An oxidation reaction paired with a reduction reaction
Copyright © 2010 Pearson Education, Inc. Figure 5.9 Oxidation-Reduction
Copyright © 2010 Pearson Education, Inc. The Generation of ATP ATP is generated by the phosphorylation of ADP
Copyright © 2010 Pearson Education, Inc. 3 Ways ATP is Produced in Living Cells 1. Substrate-Level Phosphorylation. Occurs during glycolysis (or alternate pathway) during a.Fermentation (in Microbes and our own skeletal muscle cells and brain Cells) b. Respiration: Glycolysis and Krebs Cycle 2. Oxidative Phosphorylation Occurs during respiratory e- transport chains (aerobic or anaerobic) 3. Photophosphorylation. Occurs during photosynthesis
Copyright © 2010 Pearson Education, Inc. Substrate-Level Phosphorylation A chemical reaction where a phosphate group is transferred from one molecule to ADP. This requires a specific enzyme that can transfer the phosphate from this specific molecule to ADP. This is how the process of FERMENTATION produces ATP.
Copyright © 2010 Pearson Education, Inc. Oxidative Phosphorylation Energy released from transfer of electrons (oxidation) of one compound to another (reduction) is used to generate ATP in the electron transport chain An electron transport chain(ETC) couples a chemical reaction between an electron donor (such as NADH) and an electron acceptor (such as O 2 ) to the transfer of H + ions across a membrane, through a set of mediating biochemical reactions. 2H + ionsmembrane
Copyright © 2010 Pearson Education, Inc. Photophosphorylation Light causes chlorophyll to give up electrons. The electrons go through a process similar to what happens during respiration (an electron transport chain and chemiosmosis). This process releases energy used to bond a phosphate to ADP producing ATP. The ATP produced is used to produce food molecules (sugars-glucose).
Copyright © 2010 Pearson Education, Inc. Figure 5.11 Glycolysis The oxidation of glucose to pyruvic acid produces ATP and NADH
Copyright © 2010 Pearson Education, Inc. Figure 5.10 Representative Biological Oxidation
Copyright © 2010 Pearson Education, Inc. Figure 5.12, steps 1–5 Preparatory Stage of Glycolysis 2 ATP are used Glucose is split to form 2 glucose-3-phosphate
Copyright © 2010 Pearson Education, Inc. Figure 5.12, steps 6–10 Energy-Conserving Stage of Glycolysis 2 glucose-3-phosphate oxidized to 2 pyruvic acid 4 ATP produced 2 NADH produced
Copyright © 2010 Pearson Education, Inc. Figure 5.13 Preparatory Step Intermediate between Glycolysis and Krebs Cycle Pyruvic acid (from glycolysis) is oxidized and decarboyxlated
Copyright © 2010 Pearson Education, Inc. Figure 5.13 The Krebs Cycle
Copyright © 2010 Pearson Education, Inc. Figure 5.16 Chemiosmotic Generation of ATP
Copyright © 2010 Pearson Education, Inc. PathwayEukaryoteProkaryote GlycolysisCytoplasm Intermediate stepCytoplasm Krebs cycleMitochondrial matrixCytoplasm ETCMitochondrial inner membranePlasma membrane Comparing Eukaryotic and Prokaryotic Cellular Location of Catabolic Processes
Copyright © 2010 Pearson Education, Inc. A Summary of Respiration Aerobic respiration: The final electron acceptor in the electron transport chain is molecular oxygen (O 2 ). Anaerobic respiration: The final electron acceptor in the electron transport chain is not O 2. Yields less energy than aerobic respiration because only part of the Krebs cycles operates under anaerobic conditions.
Copyright © 2010 Pearson Education, Inc. Electron AcceptorProducts NO 3 – NO 2 –, N 2 + H 2 O SO 4 – H 2 S + H 2 O CO 3 2 – CH 4 + H 2 O Anaerobic Respiration
Copyright © 2010 Pearson Education, Inc. Fermentation FERMENTATION Scientific definition: Releases energy from oxidation of organic molecules Does not require oxygen Does not use the Krebs cycle or ETC Uses an organic molecule as the final electron acceptor
Copyright © 2010 Pearson Education, Inc. Figure 5.18a An Overview of Fermentation
Copyright © 2010 Pearson Education, Inc. Figure 5.19 Types of Fermentation
Copyright © 2010 Pearson Education, Inc. Table 5.4 Types of Fermentation
Copyright © 2010 Pearson Education, Inc. Table 5.4 Types of Fermentation
Copyright © 2010 Pearson Education, Inc. Figure 5.21 Catabolism of Organic Food Molecules
Copyright © 2010 Pearson Education, Inc. Photosynthesis Conversion of light energy into chemical energy (ATP) and nutrients (glucose) Overall Summary Reaction? Compare and Contrast: Oxidative Phosphorylation and Photophosphorylation.
Copyright © 2010 Pearson Education, Inc. Photosynthesis Oxygenic: Anoxygenic:
Copyright © 2010 Pearson Education, Inc. Nutritional TypeEnergy SourceCarbon SourceExample PhotoautotrophLightCO 2 Oxygenic: Cyanobacteria plants Anoxygenic: Green, purple bacteria PhotoheterotrophLightOrganic compounds Green, purple nonsulfur bacteria ChemoautotrophChemicalCO 2 Iron-oxidizing bacteria ChemoheterotrophChemicalOrganic compounds Fermentative bacteria Animals, protozoa, fungi, bacteria. Metabolic Diversity among Organisms
Copyright © 2010 Pearson Education, Inc. Figure 5.33 Amphibolic Pathways
Copyright © 2010 Pearson Education, Inc. Figure 5.33 Amphibolic Pathways
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