Bio 12o Unit 3 Flashcards
Chapter 8, 9, and 10
2 Types of Energy Exist: Kinetic and Potential Energy
Kinetic: energy in motion
Potential: energy that is stored in position
1st Law of Thermodynamics
Energy can not be created or destroyed it can only be transfer or transformed
Potential Energy in Bonds= Chemical Energy
-Depends on positioned electrons
-Weaker bonds with equally shared electrons= high potential energy
-Stronger bones with unequally shared electrons= low potential energy
Reactants
-Weaker bonds with equally shared electrons
-HIGH potential energy
Products
-Stronger, shorter, more polar bonds
-LESS potential energy
What the engine needs»products of combustion
C8H18+12.508>8 CO2+9 H20
Isooctane+ oxygen> Carbone Dioxide+ Water
EntHalpy (H): total energy molecules
-Potential energy of the molecule effect of the molecule on the surrounding pressure and volume
-Net: total energy on bio systems
-Changes in enthalpy are primarily base on the difference in potential energy
-H< (neg.=products have lower pot. energy)
-H> (pos.= products have higher pot. energy)
Exothermic Reaction
-Release heat energy
-H<0
-Products have less pot. energy that reactant
- Ex. gas
Endothermic Reactions
-Heat energy is taken up
-H>0
-Products have higher pot. energy that reactant
-Ex. cooking and egg, melting ice
Entropy (S): amount of disorder
-Products of a chem reaction becomes less ordered than the reactant molecules
-Entropy increase
-S>0
2nd Law of Thermodynamic
-Entropy always increases
-Energy is transformed, there is always an increase of entropy
Entropy Order
Highly ordered» Increase entropy»disordered
Gibbs Free Energy(G): determines whether a reaction is spontaneous or requires add energy
Free energy change equation: G=H-TS
H= change in enthalpy
S change in entropy
T= temp. in degree Kelvin
Gibbs Free Energy (G)
G<0: Spontaneous reaction, reactions are exergonic
G>0: Nonspontaneous reactions that require energy, reactions are endergonic
G=0: reaction at equilibrium
Collision Theory
More collisions= Increase rate of reaction
Temp. & Concentration Affect Reaction Rates
-One or more chem. bonds have to break and others have to from
-Substances must collide in a specific orientation that brings the electrons involved near each other
-Higher concen. and higher temp. increase the number of collisions
-Higher concen. and higher temp. increase reaction rate
Energetic Coupling
-Between exergonic and endergonic reactions
-Allows chem. energy released from 1 reaction
-Drive another reaction
Ex. of Energetic Coupling: Redox RxNs
-Reduction, Oxidation reactions
-Redox reactions
-Chem. reactions have involve electron(e-) transfer= energy transfer
-Always occur together
-Represent energetic coupling of 2 half reactions
-During a redox reaction, e-: can be transferred or shifted
Redox RxNs Transfer Energy vis Electrons
Oxidation: loss of electrons, releases energy, exergonic
Reduction: gain of electrons, requires energy, endergonic
OIL RIG
-Oxidation Is Loss( of e-)
-Reduction Is Gain(of e-)
G=H-TS
Exergonic
G<0
Spontaneous
Reactants: Weaker bonds, higher potential energy»Products: stronger bonds, lower potential energy
Redox reactions are central in biology- they transfer energy in the form of electrons
The energy released from certain key redox reactions is used to drive the endergonic formation of ATP
ATP Transfers Energy via Phosphate Groups
Adenosine Triphosphate(ATP) is the energy currency for cells
-Provided the fuel for most cellular actives
ATP forms both between 3 neg. change phosphate groups.
-Neg. charges repel each other
-High-energy bonds store a large amount of potential energy