http://www.biotopics.co.uk/jmolapplet/atpjdisplay.htm - utline Flow of in living organism otential energy and kinetic energy Laws of Thermodynamics and energy transformations Biochemical pathways and energy transformation Anabolic and catabolic pathways Endergonic & Exergonic reactions Free energy and Redox reactions (xidation & Reduction) Activation Enzymes Forms Activity AT & Laws of Thermodynamics - the capacity to do work First Law of Thermodynamics cannot be created or destroyed can be converted from one form to another. Examples of energy? Examples of energy transformation? 1
Laws & Laws of of Thermodynamics Second Law of Thermodynamics Disorder is more likely than order Entropy is increasing. All transformations proceed spontaneously more ordered to a less ordered more stable to less stable energy dissipates as heat. Heat random motion of molecules. otential Flow of in Living Things : the capacity to do work Kinetic can take many forms mechanical electric current Chemical heat light Covalent Bonds Flow of in Living Things xidation - Reduction otential energy stored in chemical bonds can be transferred from one molecule to another by way of electrons. A o Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. xidation - Reduction Loss of electron (oxidation) B o e A B + A* B* oxidation: loss of electrons reduction: gain of electrons redox reactions are coupled to each other. Gain of electron reduction Low energy Gain of energy reduction High energy 2
M reactive group Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Biological Electron Carrier H + CH 2 H H H H H H C H 2 icotinamide Adenine Dinucleotide = AD AD + & ADH AD = Coenzyme = Electron Carrier Molecule AD + oxidized low energy AM group H CH 2 H 2 H ADH reduced high energy H H H H H H 10 Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Endergonic Reactions & Anabolism supplied A + B C + D s roducts roduct must be supplied. Fig. 8.6b (TEArt) Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Exergonic Reactions & Catabolism roduct 3
Uncatalyzed supplied Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Activation roduct Activation Catalyzed roduct Activation Enzymes Enzymes interact with substrates. Substrate: molecule that will undergo a reaction Active site: enzyme region that binds to the substrate Binding of an enzyme to a substrate (1) causes the enzyme to change shape, (2) producing an induced fit between substrates 14 Fig. 8.8 (TEArt) Active site Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Enzyme Structure and Function Substrate Fig. 8.9 (TEArt) 1 Substrate = sucrose Bond Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Enzyme Structure and Function 2 Enzymesubstrate complex H 2 Glucose Fructose 4 roducts Active site Enzyme 3 Enzyme Stresses Substrate Animation 4
What do enzymes do? Bring molecules together rients molecules in correct position Strains (bends) molecules Lowering of Activation Factors Affecting Enzyme Activity ph Temperature Releases products once formed Fig. 8.11a (TEArt) Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Temperature Effect on Enzyme Activity Fig. 8.11b (TEArt) Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. ph Effect on Enzyme Activity Human enzyme Trypsin Hotsprings prokaryote Trypsin epsin Trypsin Rate of reaction Rate of reaction 30 40 50 60 70 80 Temperature of reaction ( C) 1 2 3 4 5 6 7 8 9 ph of reaction 5
Fig. 9.2 (TEArt) Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. Biochemical pathways AT Structure AT AD + + Adenine - Triphosphate group - CH 2 - H 2 Animation High energy phosphate bond H H Sugar 21 AT - Currency of Cells The AT Cycle Coupled Reactions Stores energy in the bonds between phosphates. hosphates are highly negative, therefore: -the phosphates repel each other -much energy is required to keep the phosphates bound to each other -much energy is when the bond between two phosphates is broken from exergonic reactions hosphorylation Strongly Endergonic AD+ AT Hydrolysis Strongly Exergonic for endergonic reactions 23 Copyright 2005 earson Education, Inc. ublishing as Benjamin Cummings 6
Fig. 9.3 (TEArt) How AT powers cellular work AT Chemical work Mechanical work Transport work Membrane protein Solute + Motor protein s roduct Molecule formed rotein moved Solute transported Metabolism How is AT made? 1. AD + hosphate AT 2. Mechanisms of AT synthesis Chemiosmosis Substrate Level hosphorylation Copyright 2005 earson Education, Inc. ublishing as Benjamin Cummings AD + Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. AT synthesis: Chemiosmosis H + H + H + H + Intermembrane space Mitochondrial matrix H + H + H+ H + AT Synthase AD + AT H + - rich organic phosphate molecule Enzyme Adenosine Copyright The McGraw-Hill Companies, Inc. ermission required for reproduction or display. AT Synthesis Substrate-Level hosphorylation AD - poor organic molecule Adenosine AT 7