Energy, Enzymes, and Biological Reactions Ch. 4; 4.1-4.3

Energy, Enzymes, and Biological ReactionsCh. 4; 4.1-4.3

All You Need is EnergyAll living things require energyMove, grow, reproduce, consume, think, react, etcThousands of energy requiring chemical reactions are occurring right nowMetabolism the total amount of materials and energy used by a living thing What factors effect metabolism?Body sizeAmount of activityDietRate of growth

How Do We Measure Energy?Energy itself cannot be measuredWe measure energy through its interaction with objects/forces around usEnergy the capacity to do workForms of energy?MechanicalChemicalRadiantElectrical

Types of EnergyWhat are the two types of energy?Kinetic and PotentialKinetic energy in motionBall rolling down a hillElectricity heatPotential stored energyBall on top of a hillChemical bondsHow do these terms describe a roller coaster?

Systems and SurroundingsThermodynamics study of energy flow between a system and its surroundingsTypes of systems:Isolated no exchange of matter or energyClosed only exchange energyOpen exchange both matter and energy

1st Law of ThermodynamicsEnergy cannot be created or destroyed; it can only be transferredThe total amount of energy in a system/surroundings remains constantWhere does the energy we use come from?The SunWhat conversions are needed to get you to read this slide:

At each step energy is lost has heat (K) The movement of heat and the kinetic energy inside organic molecules determine if reactions occur in living thingsReactants have more energy than their products

nuclear(P)radiant(K)chemical(P)chemical(K)mechanical(K)

2nd Law of ThermodynamicsThe total disorder (entropy) of a system and its surrounds always increasesLiving things increase in order as they growCellsTissueOrgansDo living things violate this law?No. Taking into account of the surroundings, the waste produced by living things has a higher entropy than the order inside the system

Spontaneous Reactions1st and 2nd law determine if a reaction is spontaneousTwo trends:Negative enthalpy (-H)Exothermic; products have less energy than reactantsEndothermic; (+H); reactants have less energy than products2) Negative entropy (-S)Products have less order than the reactantsWhy are a combustion reaction (exothermic) and melting ice (endothermic) both spontaneous?

Free Energy determines SpontaneityG= H-TSG= energy releasedH= enthalpyT= temp (Kelvin)S= entropyIf there is a large enough H or enough disorder, large S, the G will be negative-G= Release of free energyCombustion reaction:- H is large enoughMelting ice:- S is large enough

Biology Reactions over TimeChemical reaction can run till completion (run out of reactants)Biological reactions always slow as they research a chemical equilibrium pointForward rate = Reverse rateG=0, the reaction stops; no longer spontaneousDoes this occur in a living thing?No. Living things consume new reactants and use products in other reactionsG=0=death for living things

Metabolic PathwaysBiological reactions are divided into two groupsExergonic reactions (-G)Endergonic reactions (+G)Mixing of these types create reaction series metabolic pathwaysCatabolic breakdown molecules to release energy through catabolic reactionsAnabolic build energy storage molecules through anabolic reactions (biosynthetic reactions)Can you give me an example of both of these pathways?

How is this free energy getting around?Adenosine triphosphate (ATP)5-C sugar (ribose)Adenine nitrogenous base3 phosphate groupsStrong negative charges between P-groups make molecule unstable and releases -7.3 kcal/mol when 3rd P is removed (hydrolyzed)Where does that energy go? How much is lost as heat?

Energy Coupling3rd P-group is transferred from ATP to the reactant molecule (phosphorylation)Phosphorylated molecules use the energy to power their reactionGlutamic acidGlutamineAdding an ammonia; G= +3.4 kcal/mol; endergonicFirst add a P-group from ATP; Glutamic acid + PGlutamyl phosphate

-7.3 kcal/mol+ 3.4 kcal/molreaction is-3.9 kcal/mol exergonic

ATP of Everyone: ATP/ADP Cycle50 trillion cells in an adultMillions of molecules, enzymes, pathways, etc.. all using 10 million molecules of ATP every second About 75kg of ATP per dayComplex systems living on a demand for energy to replace our ATPHow much ATP are you using?

HomeworkFinish reading Ch. 4Ch. 4 vocab listGo to this site:http://www.freedieting.com/tools/calorie_calculator.htmCalculate your daily Calorie in take. Of this energy only 40% can be used as ATP in the body. How many moles of ATP do you need a day? How many grams of ATP is that? What happened to the other 60%? Show work in your notebook1 ATP 7300 caloriesATP 507 g/mol

Exercise between studying subjects