Bio Chapter 1 - Water Molecule

Importance to our systems

Blood circulating dissolved ions, and molecules, causing reactions involving oxygen and carbon dioxide to be picked up and transported to and from tissues and lungs; blood circulating nutrients and ions to tissue cells and removing wastes

Water as a temperature regulator

Hydrogen bonds in water cause water to absorb and release heat (energy) slowly. This protects cells from rapid temp change - High heat of vaporization in order for water liquid to turn to gas, it must use a lot of heat. When we sweat, the evapouration uses a lot of body heat which cools our body. - High specific heat

Water as an Cohesive & Adhesive

cohesion and adhesion allow water to fill a tubular vessel - This allows water to serve as an excellent medium for transport of nutrients and wastes in the body.

Universal Solvent (Dissolving Agent)

-Due to its polarity, water molecules surround and break apart molecules -As a result, the ions and molecules move around, collide and cause reactions to occur -Water will then transport these ions and facilitate chemical reactions outside and inside cells

Water as an universal dissolving agent

-Due to water's polarity, water molecules surround and break apart other molecules - as a result ions and molecules move around, collide, and cause reactions to occur. - H2O transport ions and facilitate chemical reactions

Association of Two Water Molecules

-Hydrogen bonds form between adjacent water molecules -The covalent bonded positively charged H is attached to the negatively charged O by a H-bond -The water will dissociate (separate) into ions (the bonds break when energy is supplied) E.g. H2O --> H+ + OH-

Water/H2O

-Not an organic molecule i.e. does NOT contain carbon -Water is an inorganic, polar molecule -Bonds between Hydrogen and Oxygen are covalent i.e. they consist of pairs of shared electrons to become stable

Water: a polar molecule

-The electrons of a H2O molecule are shared unevenly and spend more time orbiting oxygen than hydrogen -This results in a slight positive charge on the hydrogen side and a slight negative charge on the oxygen side, therefore making H2O a polar molecule -The characteristic of unequal sharing of electrons accounts for the polarity of water

Lubricant

Lubricates cell parts to reduce friction. (tears, saliva)