Basics Flashcards
What is metabolism?
the sum of all chemical reactions occurring in a living organism
Chemical reactions in cells
-Involve energy changes
-catalyzed by enzymes
-enzymes attempt to drive the reaction toward equilibrium
-as enzyme-catalyzed reactions proceed toward equilibrium they release energy
Bioenergetics
chemical thermodynamics as it applies to living organisms (energy changes in chemical systems)
How is energy used in living organisms?
-Anabolism
-Muscle contraction
-Transport Process
-Control mechanisms
What are the laws of thermodynamics?
First: in any physical or chemical change, the total amount of energy in the universe remains constant, although the form of energy may change
Second: in all natural processes, the entropy of the universe increases
Delta H
Enthalpy change: change in form, reactants to products, endothermic/exothermic
Exothermic reaction
heat energy is given off, energy released (-delta H)
Endothermic reaction
requires energetic input, (+delta H)
Entropy Change
Increase in the randomness or disorder within a system (Delta S)
measure of energy dispersal, diffusion of energy when randomness increases delta S is positive.
First Law of Thermodynamics
in any physical or chemical change, the total amount of energy in the universe remains constant although the form of the energy may change
Second law of thermodynamics
in all natural processes,the entropy of the universe increases
-teakettle, oxidation of glucose
Delta G
Free energy change:L the maximum energy available from a reaction or process that can be harnessed to do something useful.
Exergonic Reaction
free energy released
spontaneous
favorable reaction
can occur by itself
-delta G
Endergonic Reaction
Energy is required
not spontaneous
not favorable
can’t occur by itself
Free Energy Change Equation
Delta G= Delta H - T(Delta S)
enthalpy change -temperature (kelvin) times entropy change
Delta G > 0
free energy of the product is higher than free energy of the reactants (endergonic)
Delta G < 0
Free energy of the products is lower than the free energy of the reactants (exergonic)
Delta G = 0
No free energy change, state of dynamic equilibrium
Stanard free energy change equation
Delta G= Delta G^’ + RT ln ([C][D]/[A][B])
Delta G^’= standard free energy change (1.0M, 25C,pH 7.0)
R= gas constant (8.315J/mol)
T= absolute temperature (K)
ln= natural log
Keq
= 1 at equilibrium
Equilibrium Constant: (Reactants/Products)
PCr
Creatine Phosphate:
ATP
Adenosine Triphosphate
Nitrogenous Adenine Base
5 carbon ribose (beta deoxyribose)
three phosphryl groups
Hydrolysis of phosphoanyhidride linkages releases a lot of energy, can be hydrolized at either but not simultaneously
Hydrolysis between Beta and y group is more common
Which molecule is represented here?
ATP
Hydrolysis of ATP (between beta and y phosphoryl groups)
atp+h20 <> ADP +Pi + H+
1 atp + 1 water = adp, inorganic phosphate and a hydrogen ion
Hydrolysis of ATP (between alpha and beta phosphoryl groups)
AMP + PPI
Adenosine monophosphate and inorganic pyrophosphate
