BIOL 1201 9 18 15 Flow of energy within a cell 2 major metabolic processes mitochondrial photosynthesis What is energy energy the capacity to do work we all have energy and are working right now using stored potential energy to converting it to kinetic energy kinetic energy energy of movement light movement of photons 1 2 mg 2 we are being hit by energy right now solar panel will take the photons and convert it to electricity w help of elec plants absorb photons and store it never 100 cant use 10 of it trons in the wire heat useless energy electricity potential energy stored energy chemical energy be stored tial energy than Dr Pollock batteries ex charging your phone battery not all the energy is used it has to positional energy anyone higher or heavier in the room will have a greater poten Laws of Thermodynamics 1st law conservation of energy amount of energy in a system remains constant system could be energy in this room energy in LA energy in BR our solar system interacts with the stars and the galaxies not a closed system have to know what comes in and what comes out 2nd law when converted from one form to another useful energy decreases Gasoline is a hydro carbon chain of carbons bonded together hydrogens hanging off each carbon both represent stored energy more bonds more energy we change the bonds potential energy into kinetic energy about 25 of the energy is converted into the movement of the car down the road 1 of 21 BIOL 1201 not a very efficient process not a lot of useful energy the other 75 is converted to heat if you let go of the gas pedal the KE is lost to friction heat but all the energy is still accounted for even though it may not be useful entropy measure of disorder increases Energy Flow on Earth energy input for the sun photoautotrophs plants other producers heterotrophs consumers decomposers energy output mainly heat How does energy flow in chemical reactions chemical reaction forming and breaking chemical bonds among atoms chemical bond is broken energy is released chemical bond is formed energy is stored water has 2 chemical bonds oxygen and 2 hydrogens equilibrium with pH 7 breaks down into hydrogen and hydroxide H OH reactants substrates starting materials products result of the reaction exergonic reactions A B high energy reactants C D low energy products energy releasing reaction at the yield glucose 6 carbon sugar and oxygen are a high energy reactants breaking all the bonds in the ring of 6 carbons energy is released in the form product water and carbon dioxide are low energy products energy is released cellular respiration burning glucose sugar is an exergonic reaction glucose and energy need the activation energy to ignite glucose think back to A E is provided through enzymes proteins that catalyze the reaction enzyme allows the reaction to take place with less energy of heat as well 1208 2 of 21 BIOL 1201 endergonic reactions requires energy C D low energy reactants A B high energy products water and carbon dioxide yields oxygen and glucose got the required energy from the sun NOTE not all the capture energy from the sun is used photosynthesis an endergonic reaction Coupled Reactions exergonic reaction ATP 100 units energy released ADP P ATP adenosine is adenine has 3 phosphates if the last phosphate is removed en ergy is released giving off energy endergonic reaction relaxed muscle 20 units of energy contracted muscle coupled reaction relaxed muscle ATP contracted muscle 8 units energy re leased as heat ADP P explains why when working out you get hot How is Cellular Energy Carried Between Coupled Reactions Phosphorylation ATP shorthand representations A p p ADP energy content low 3 of 21 BIOL 1201 A p p p ATP energy content high notice there is an extra phosphate both are 5 carbon sugars with adenine and 2 or 3 phosphate group 9 21 15 Synthesis of ATP Readily Available Energy substrates ADP energy and phosphate product ATP Breakdown of ATP Releasing Energy for Work ATP is broken down to energy ADP and a free phosphate this is the main use of ATP glucose is a good source of energy in using substrates because they are enzy our diet matic reactions will breakdown on its own but adding a catalytic enzyme it will happen a lot faster 4 of 21 BIOL 1201 Couple Reactions within Living Cells glucose is broken down into CO2 and H2O and heat this is a multi step process energy is released exergonic from the bonds between the 6 carbon chain called glu cose versal donors in the cell ple reaction some is lost in the form of useless energy heat and others is transferred to uni glucose lets off energy and ATP requires energy endergonic so it is a cou ATP can then be broken down into ADP and phosphate exergonic and that energy can now be used to produce a protein endergonic Electron Carriers high energy electrons transferred from one reaction to another there are other things other than ATP that can move energy How Do Cells Control Their Metabolic Reactions Metabolism sum of all the chemical reaction in a cell most of these reactions are catalyzed chemical reactions exergonic endergonic metabolism Metabolic pathway series of reactions linked in a sequence one reaction followed by another is known as an enzymatic pathway they occur often in our cells start with our building blocks initial reactants a which is recognized by enzyme 1 and is catalyzed to produce intermediates enzyme 2 recognizes B and produces C enzyme 3 recognizes C and product b produces D 5 of 21 BIOL 1201 final products enzyme 4 recognizes D and produces E enzyme 5 recognizes C and produces F intermediate same substrate as enzyme 3 but makes a different product enzyme 6 recognizes f as substrate and produces G final about 6 genes were needed to produce final products E and G How is metabolism controlled proteins enzymes regulate chemical rxns cells couple rxns using proteins enzymes energy carriers ATP NADH NADPH capture energy from exergonic rxns and deliver to endergonic rxns Catalysts lysts catalytic converter in the exhaust of your car non biological cata catalysts speed up chemical reactions helps clean the exhaust the least amount of reactions the better enzymes are biological catalysts usually proteins ribozymes sometimes other things like RNA Activation Energy Controls Rate of Reaction exergonic reaction the energy at the end of the reaction is lower 6 of 21 BIOL 1201 action enzymes speed up chemical reactions by requiring less activation energy to perform a re 5 properties of