Chapter 3 Cell Metabolism Chemical Reac4ons and Energy The types of reac ons that provide cells the energy needed to perform their work Where are we going Metabolism How cells acquire the energy they need Membrane Transport How cells import that materials needed to survive Glucose Transport Chemical Messengers How cells communicate with each other to maintain a constant internal environment Insulin Ac on Endocrine System How hormones are used by cells for long distance communica on in the body Chemical Reac ons and Energy Chemical reac ons are always accompanied by either the release of energy or the input of the energy The released energy might be heat or take some other form and under certain condi ons it can be used to perform work The Ac va on Energy Barrier However in order for any reac on to proceed the reac ng molecules must pass through a high energy transi on state Where does this energy come from Collisions Converts their kine c energy mo on to poten al energy For reactants to become products or vice versa molecules must have su cient poten al energy to surmount the ac va on energy barrier What if this gain in poten al energy is not equal to or greater than the ac va on energy Then no reac on will be produced So what can you do then Could increase Temperature Concentra on of reactants Could decrease Ac va on barrier The Role of Enzyme in Chemical Reac ons Cells contain a wide variety of enzymes each specialized to catalyze a par cular reac on or group of reac ons Enzymes help to stabilize the transi on state thereby decreasing the ac va on energy barrier Substrate Speci city Reac ons in Metabolism Condensa on and Hydrolysis Reac ons Phosphoryla on and Dephosphoryla on Reac ons Oxida on Reduc on Reac ons Types of Metabolic Reac ons Condensa on and Hydrolysis Reac ons Types of Metabolic Reac ons Hydrolysis Reac ons Types of Metabolic Reac ons Condensa on Reac ons DNA Polymerase III Types of Metabolic Reac ons Phosphoryla on and Dephosphoryla on Reac ons Phosphoryla on and Dephosphoryla on Reac ons Types of Metabolic Reac ons Oxida on Reduc on Reac ons Metabolic reac ons that occur in the body enable cells to transform raw materials from the environment into the cellular energy needed to do work Types of Metabolic Reac ons Oxida on Reduc on Reac ons Overview of Glucose Oxida on