1. Introduction


a characteristic that distinguishes physical entities that have biological processes, from those that do not.

Characteristics of Life

1. Growth (Consumption, Excretion)
2. Respond to external stimulation
3. Adapt to the environment
4. Reproduction


An equilibrium of parameters that define the internal environment of a system


A measure of disorder in the system. (or of the availability of the energy in a system to do work).

Second Law of Thermodynamics

The total entropy of an isolated system can never decrease over time.
(basically, everything decays over time.)

Erwin Schrodinger states that:

Life, contrary to the general tendency dictated by the second law of thermodynamics, decreases or maintains its entropy by feeding on free energy.
(Life is the ability to maintain or decrease the level of entropy (disorder).)

Living systems must be:

Open-Exchange with environment.

How to Decrease Entropy:

We must be able to acquire and utilize energy from the environment.

Gibbs Free Energy (?G)

-The amount of energy available during a chemical reaction to do cellular work.
?G- Gibbs free energy(J/mol)
?H- Change of Enthalpy(heat)(kJ/mol)
T- Temp. in Kelvin
?S- Entropy change-- drive towards disorder (J/K*mol)

Louis Pasteur Experiment

Refute Spontaneous Generation

4 Major Macroelements in Body

Oxygen, Carbon, Hydrogen, Nitrogen


Primary building blocks of living cells


The chemical processes that occur within a living organism in order to maintain life.


Processes of synthesis and storing energy, 'constructive metabolism'
-Protein biosynthesis, gluconeogenesis


Breakdown of molecules, release of energy, 'destructive metabolism'
-Glycolysis, TCA cycle, Oxidation of fatty acids.


The 'Manual' we pass onto further generations.