Quiz 2 Reading Info Flashcards
Energy transductions
conversions of one form of energy to another
Antoine Lavoisier
French chemist who recognized that animals somehow transform chemical fuels (food) into heat and that this process of respiration is essential to life
First law of thermodyanmics
Total amount of energy in the universe is constant
The form of energy may change, but energy cannot be created or destroyed
Second law of thermodyanmics
in all natural processes, the entropy of the universe increases
What type of systems are living organisms?
they are open systems
Gibbs Free Energy, G
expresses the amount of energy capable of doing work during a reaction at constant temperature and pressure
Exergonic and endergonic reactions refer to
Change in delta G
Endothermic and exothermic reactions refer to
Change in enthalpy (H)
Exothermic reactions
delta H is negative
heat is released
surroundings feel warm
ex: gas burning
Endothermic reactions
delta H is positive
heat is consumed
feels cold, since energy is taken from the environment
Enthalpy, H
is the heat content of the reacting system. it reflects the number and kinds of chemical bonds in the reactants and products
Entropy, S
quantitative expression for the disorder in a system
Units of G and H
joules/mole or cal/mole
Units of S
joules/moleKelvin (J/molK)
How do cells become so ordered and seem to disobey the second law of thermodyanmics?
the order produced within cells as they grow and divide is more than compensated for by the disorder they create in their surroundings in the course of growth and division
isothermal systems
function at essentially constant temperature and constant pressure
cells are isothermal systems
Is heat flow a source of energy for cells?
No
Cells only use free energy to do work
Standards condition for the cell
25ºC - temperature
101.3 kPa / 1 atm - pressure
pH 7 - [H+] concentration
55.5 M - constant water concentration
Standard transformed constants
use the prime ‘ mark because they are occuring in the biochemical standard state
What is not included when solving for Keq and the mass-action ratio, Q ?
H20, H+, and/or Mg2+
Their concentrations are not included
Relationship between K’eq and ΔG’º?
ΔG’º = -RTln(K’eq)
What happens when K’eq is >1.0?
ΔG’º is negative and the reaction proceeds forward
What happens when K’eq is <1.0?
ΔG’º is positive and the reaction proceeds in reverse
What happens when K’eq is 1?
ΔG’º is zero and the reaction is at equilibrium