Phase transitions in biological systems

image from http://www.chemistry.wustl.edu/%7Ecourses/genchem/LabTutorials/Thermochem/images/PhaseChanges.jpg

Phase transitions are present everywhere. Even within something as complex as the human body or plants, phase transitions are still present throughout processes which these systems use to survive.

The Human Body as a Biological System

Respiratory System

Oxygen gas

Digestive System

Breakdown of food for energy. ATP.

Circulatory System

Transportation

Nervous System

Various signaling pathways

Reproductive System

The fertilization of an egg by sperm is irreversible.

Plants as a Biological System

Photosynthesis

Images from Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com)

Biological Thermodynamics

Biological Thermodynamics combines the laws of thermodynamics with biology in order to explain or possibly quantify changes in energy from reactions. Many organ systems within the human body, (if not all of them), require some energy in order to function. In a plant, photosynthesis converts sunlight to energy usable by the plant so that it may synthesize sugars out of carbon dioxide gas and water. There has to be some sort of method to quantify the energy required in these reactions.

Sources

1. “Digestion”, 15APR09, <http://en.wikipedia.org/wiki/Digestion>

2. Fox, Stuart Ira, “Human Physiology”, 10th Edition, McGraw-Hill Companies, 2008

3. “MIT Department of Physics: Biophysics: Biological and Medicine”, 15APR09,< http://web.mit.edu/physics/research/areasofresearch/atomic_cm_plasma/biophysics/biophysics.html>

4. “Nervous system”, 15APR09, <http://en.wikipedia.org/wiki/Nervous_system>

5. “Phase Changes”, 15APR09, < http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/phase.html>

6. “Phase transition”, 15APR09, <http://en.wikipedia.org/wiki/Phase_transition>

7. “Photosynthesis”, 15APR09, <http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPS.html>

8. “Photosynthesis”, 15APR09, <http://en.wikipedia.org/wiki/Photosynthesis>

9. “Soft Condensed Matter: where physics meets biology”, 15APR09,< http://physicsworld.com/cws/article/print/169>

10. “Types of Photosynthesis”, <http://wc.pima.edu/~bfiero/tucsonecology/plants/plants_photosynthesis.htm>

11. "Biological Thermodynamics", <http://en.wikipedia.org/wiki/Biological_thermodynamics>