Chemistry of Life

Carbon, Hydrogen, Oxygen and Nitrogen.

It can form long chains and rings.

Large molecules including polysaccharides, proteins and nucleic acids.

Repeating sub-units formed by polymerisation. (monosaccharides, amino acids and nucleotides)

Cellulose and rubber (natural)

Pvc, polyethene and polystyrene (man made)

-Excellent solvent for ions and polar molecules

-Water molecules are attracted, surround and seperate them

-Once the chemical is in solution it can move around to react with other chemicals

-Most processes therefore happen in solution

-Non-polar molecules in contrast are pushed together as water attracts to itself

-This gives stability to structures such as plasma membranes and proteins

In blood, lymphatic, excretory and digestive systems and in vascular plants

-hydrogen bonds hold water together

-as a consequence a relatively large amount of energy is required to raise the temperature

-this means water habitats are stable and have small fluctuations in temperature

-also internal temperature is easier to maintain

-evaporation therefore is an efficient way of removing large amounts of excess energy eg. sweating