Week 2 - Thermodynamics Flashcards
What is the 1st law of thermodynamics?
The total amount of energy within a system and its surroundings is constant
Energy can be neither created nor destroyed, only interconverted between forms
What is the 2nd law of thermodynamics?
The total entropy (the level of disorder) of a system and its surroundings always increases
What is the 3rd law of thermodynamics?
The entropy of a system approaches a constant value when its temperature approaches absolute zero
What is the equation of Enthalpy?
Internal energy + (Pressure X Volume)
What is an exothermic reaction?
Release of heat (energy) during a reaction
What is an endothermic reaction?
Heat (energy) is absorbed during a reaction
What does entropy mean?
Refers to the level of disorder in a system (how energy is distributed in a system)
What is Gibbs Free energy?
The amount of available energy to do work
Equation for Gibbs free energy (G)
Change in enthalpy - (Temperature (K) X change in entropy)
What is the value of G in a sponaneous process?
G < 0
What is the value of G in a non spontaneous process?
G > 0
What is a coupled reaction?
Fundemental to metabolism
A reaction cannot occur spontaneously if change in G > 0. An energy inout is required
What is the process of activated carriers?
1 - Energy released by oxidation of organic molecules can be stored, preventing it being lost as heat
2 - Energy stored in molecules termed activated carriers, as either a transferable chemical group or electrons.
3 - Then used for endergonic reaction (+G) for other cell activities.
What is ATP?
It is an activated carrier molecule that drives non-energyetically favourable reactions in our body
How do cells obtain energy?
- Cells obtain energy through the oxidation of organic molecules (food)
- Energy is stored in covalent bonds of these organic molecules
