Homework: Read chapter 3 and answer the Concept Check Questions

“Survival of the fittest”

The fitness of the environment Life adapts to its environment through natural selection The environment must be a suitable abode for there to be life at all.

Water 1.Hydrogen bonding 2.Emergent qualities 3.Dissociation leads to acidic and basic conditions.

Hydrogen Bonding Oxygen is more electronegative than hydrogen Oxygen in water is partially negative; hydrogen partially positive.

Emergent Properties Cohesion Moderation of temperature Expansion upon freezing Versatility as a solvent..

Mole

Take the atomic mass, say it in grams, and it’s a mole. Mole

Take the atomic mass, say it in grams, and it’s a mole x AMU = 1 g Mole

Take the atomic mass, say it in grams, and it’s a mole. One atom of water

Mole Take the atomic mass, say it in grams, and it’s a mole. One atom of water 16 AMU 1 AMU

Mole Take the atomic mass, say it in grams, and it’s a mole. One atom of water AMU

Mole Take the atomic mass, say it in grams, and it’s a mole. One mole of water 18 g

Molar One molar equals one mole of solute per liter of solution 1 M = 1 mole/L

Molar One molar equals one mole of solute per liter of solution Na = 23 AMU Cl = 35.4 AMU NaCl = 58.4 AMU

Molar One molar equals one mole of solute per liter of solution Na = 23 g Cl = 35.4 g NaCl = 58.4 g

Molar One molar equals one mole of solute per liter of solution 58.4 g 1 L

Molar One molar equals one mole of solute per liter of solution 58.4 g 1 L

Molar One molar equals one mole of solute per liter of solution 1 L 58.4 g

Molar One molar equals one mole of solute per liter of solution 1 L 58.4 g

Molar One molar equals one mole of solute per liter of solution 1 M = 1 mole/L 1 L 58.4 g

[H + ] for pure water at 25 o C = M pH = -log [H + ] More H + means more acidic 1 pH unit = 10x change in acidity. Dissociation

Minimize changes in pH Usually a weak acid and its corresponding base. Buffers

“Oil and water do not mix” Why not? Can we make them mix?

Water has polar covalent bonds Oil has non-polar covalent bonds Soap has both. Polar and Non-Polar

Phospholipids

Hydrophobic molecules dissolve in the lipid layer and cross it easily Hydrocarbons (oils), CO 2, O 2. Selective Permeability

Hydrophilic molecules are blocked by the lipid layer Ions, water, etc Cell uses transport proteins to carry hydrophilic substances. Selective Permeability

Diffusion Concentration gradient No energy is expended Osmosis = diffusion of water. Passive Transport

Water moves from hypotonic solution to hypertonic solution Isotonic = same concentration “Water potential” includes solute concentration and pressure. Osmosis

hypo hyper

Osmosis hypo hyper.