BIOL 1411 1st Edition Lecture 11Outline of Last Lecture 1. Energy transformation 2. Enzymes characteristics3. How enzymes workOutline of Current Lecture 1. Finish up enzymes from last lecture2. Overview of glucose3. 3 metabolic pathways4. Redox overview5. Discuss glycolysis in detailCurrent Lecture(continuation of how enzyme activities are regulated from last lecture)- Allosteric Regulation (type of noncompetitive regulation)o A type of noncompetitive regulationo Enzymes can exist in more than one shape Active form can bind substrate Inactive form cannot bind substrateo Most allosteric enzymes are proteins with quaternary structure  Catalytic subunit with active siteThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Regulatory structure to which a small molecule (effector) can bind Effector molecule induces change in shape in enzyme Effectors can wither inhibit or activate an enzyme with a certain range, reaction rates for allosteric enzymes are sensitive to small changes in substrate concentration allosteric enzymes important for regulating metabolic pathways- very sensitive to small changes in concentration of noncompetitiveinhibitors metabolic pathway navigation - first reaction – commitment step, other reactions then happen in sequence- when enough end product is present, whole pathway will than turned off- feedback inhibition (end-product inhibition)o final product acts as a noncompetitive inhibitor of the first enzyme - the following image is a key concept of living systems-- Physical environment also effects enzyme activityo Ph Every enzyme is most active at a particular pH pH influences the ionization of functional groups this affects folding and thus enzyme functiono temp every enzyme has an optimal temperature High temp-noncovalent bonds begin to break Enzyme can lose its tertiary structure and become denatured(end of lecture 10 notes)Lecture 11 – Chapter 9 bioenergetics- Fuelso Carbon based molecules whose stored energy can be released for use- Energy is released through oxidation reactions that breakdown the fuel molecules into simpler molecules, such as CO2- Glucoseo Most common fuel in organismso Cell metabolism converts other molecules into glucose or intermediates of glucose oxidationo Polymers of glucose are used by plants and animals for energy storage- Principles governing metabolic pathwayso Complex chemical transformations occur in a series of reactionso Each reaction is catalyzed by a specific enzymeo Metabolic pathways are similar in all organismso In eukaryotes, metabolic pathways are compartmentalized in organelleso Each pathway is regulated by key enzymes – usually allosteric mechanisms- Three metabolic pathways are involved in harvesting the energy of glucose o Glycolysis  Glucose converted to pyruvate Most ancient of the processes and is the starting point for both of the other processes o Cellular respiration Aerobic (O2 present) and converts pyruvate into H2O and CO2; leads to synthesis of much ATP complete oxidation waste products are H2O and CO2 net energy trapped per glucose is 32 ATPo Fermentation Anaerobic (O2 absent) and converts pyruvate into lactic acid or ethanol + CO2; produces little ATP Incomplete oxidation Waste products are lactic acid or ethanol and CO2 Net energy trapped is 2 ATP- All glucose oxidation reactions involve electron transfer reactions = REDOX reactionso Reduction – gain electronso Oxidation – losing electronso Redox reactions also occur if hydrogen atoms are gained or lost o Oxidation and reduction occur togethero Refer to oxidation reduction slides if more information neededo Glucose oxidation releases chemical energy in cells Glucose oxidized, oxygen becomes reduced All electrons part of H atom in glucose are transferred to molecules of oxygen to form water Energy from bonds of glucose is transferred  If all energy was released in one step=blazing heat and a fried cell!- Series of reactions, each releases a small amount of energy that can be captured for endergonic reactions Nicoo Nicotinamide dinucleotide production Controlled steps of glucose reactions are catalyzed by enzymes Coenzyme NAD+ is a key electron carrier in redox reactions- NAD+ (oxidized)o Receives electron from glucose- NADH (reduced) o Carries electron from glucose to other molecules in the mitochondria, ultimately to the O2-- like ATP and ADP, it cycles back and forth between one state and the othero Glycolysis Discussed before Starting point for all energy harvesting processes  Inputs- Glucose (C6H12O6)- 2 NAD+- 2 ADP + 2P i Outputs- 2 molecules of pyruvate (C3H4O3)- 2 NADH (has those other 4 H atoms from glucose)- 2 ATP (net) 10 enzyme-catalyzed reactions- Reactions 1-5o Energy investmento Adding P to glucose- Reactions 6-10o Energy payouto In NADH and 2 ATP (net) (reactions