First cell
Supposed to have evolved in oceans
Why water?
Water is a solvent that allows for complex biochemical reactions to occur
Aqueous solution
Any solution where water is the solvent: Cytoplasm, rivers and blood are all examples of this
Covalent Bond
When 2 atoms share electrons
Non polar covalent Bonds
electrons are negatively charged and nucleus is positively due to protons, so equally shared electrons create non polar covalent bonds
Because neither atom has higher electron density than the other
Polar Covalent Bonds
Covalent bonds between oxygen and hydrogen within water molecules because 1 oxygen electron bonds with 2 hydrogen electrons resulting in a slight negatively charged bond
Unequal sharing of electrons
Ephemeral attractions
Short lived attractions between water molecules and other charged atoms (ions)
Cohesion
When molecules of the same type are attracted to one another
Hydrogen Bonding
When slight positive and negative charges are attracted to one another. An ice crystal forms because of the slowing down of the molecules so that the bonding is frozen
Molecular Motion
Speed of molecules interacting = fast or slow, slow leads to ice crystals due to the freezing of bonds, fast leads to quicker interactions
Surface Tension
Caused by ephemeral hydrogen bonding
Lack of molecules above water surface leads to increasing cohesive force of around and below molecules
Tension
Pressure created by the cohesion of water molecules as evaporation occurs
Adhesion
Attraction of 2 unlike molecules due to hydrogen bonding
Hydrophilic
Dissolves easy in water
Loves water
Hydrophobic
Does NOT dissolve easily in water
Hates water
Enzymes
A dissolved proteins in cells that are biological catalysts
Require specific rates of life and temperatures tolerated by that type of cell
Catalyst
Substance that increases the rate of a chemical reaction without going through any permanent chemical change
Properties of Water
Buoyancy
Viscosity
Thermal Conductivity
Specific Heat Capacity