Biology 1001A Lecture : Bio lectures 2-5.doc

• School: Western University
• Department: Biology
• Course: Biology 1001A
• Professor: Tom Haffie

Document Summary

General focus of these next few lectures: origin of cells and how cells. Two hydrogens and only one oxygen: oxygen is quite electronegative b, water dissociates into oh- and h+ d) Answer: a) oxygen has a large nucleus, high affinity for electrons being shared in a water molecule so electrons spend more time orbiting oxygen, making them slightly more negative and the hydrogens slightly positive making water polar. The polarity makes individual water molecules attract each other. Stick together (ie doesn"t like to be gas) The oxygen (-) end of one water molecule attracts the hydrogen (+) end of another water molecule. This means that water is liquid at ambient temperatures on earth (ie because of high polarity and intermolecular attraction) Attraction between water molecules squeezes out the oil which is less dense so it ends up floating on the top. Stearic acid, long hydrocarbon, no polarity, very equal distribution of electrons.