Thermodynamics Flashcards
Thermodynamics
The study of energy and hot it is distributed
Gravitational potential =
Mass x height x acceleration
Energy
The capacity to do work
Thermal energy =
Heat capacity x temperature
First law of thermodynamics
The amount of energy within the universe is constant, energy cannot be created or destroyed (ALL energy came from bing bang)
Second law of thermodynamics
- Descrbies the observation that energy moves from an area of high concentration to one of low concentration.
RULES:
1. Heat will spontaneously flow from a material at high temperature to a material at lower temperature
- Some heat energy is lost when energy is converted
- In an isolated system a process can occur only if it increases the total entropy of the system.
- Disorder in the universe tends to increase
Was the big bang low or high entropy
Low entropy - all energy in an infinitely small single point - infinitely ordered
Enthalpy
The energy required to form a system.
Change in enthalpy =
Enthalpy of formation
of product - Enthalpy of formation of reactants
How does life exist
By using energy to increase order (decrease entropy)
Change in Entropy =
Enthalpy of formation
of product - Enthalpy of formation of reactants
Gibbs free energy =
Enthapy - (Temperature x Entropy)
How do you know if a reaction is feasible
- If ΔG is LESS than 0 the reaction will run forward
- If ΔG is GREATER than 0 the reaction will run backwards
- If ΔG is at 0 the reaction is at equilibrium
Activation energy
Energy required for a reaction to proceed, it controls how fast a reaction will reach equilibrium
How does biology get unfavourable reaction to work? Example…
- Calcium pump, uses ATPase to make calcium go against its concentration gradient
What do enzymes do
Enzymes increase the rate of reaction by reducing the activation energy of a reaction, BUT do not change the equilibrium for a reaction
Substrate binding
Held in place by
- Hydrogen bonds
- Ionic bonds
- Hydrohpobic interactions
Lock and key model
Substrate is complimentary to the active site
Induced fit
The enzyme and substrate bind and undergo a change in conformation and stabilise the transition state and reduce the activation energy so the reaction can proceed.
Negative delta G name
Exergonic
Negative delta G name
Endergonic
Enzyme promiscuity
Enzymes can have different reactions
Broad specificity
Same reaction different substrate leads to different product
Methods for measuring concentration of substrate or product
- Colour
Substrates and products can have a colour. Eg. In the reaction with NITROCEFIN the susbtrate is yellow and the product is red.
You can also use a spectrophotometer to measure the absorption of ultraviolet light, eg NADH and FADH absorb a specific wavelength of light - Catalase reaction
measuring the change in state going from liquid to gas so testing if the gas is present - Size
Some enzymes alter the size of substrates. Eg DNA restriction endonuclease breaks down DNA
