Solubility, Water, Molarity, and pH

hydrophilic

molecules that dissolve easily in water, tend to be polar and lipophobic

hydrophobic

molecules that do not easily dissolve in water, tend to be non polar and lipophilic

amphipathic

• example

molecules that contain both hydrophobic and hydrophilic regions

• phospholipid

What is the importance of amphipathy in the cell membrane?

gives membrane semipermeable membrane, only small nonpolar molecules can pass.

What are the 5 unique properties of water

1) solid water (ice) is less dance than liquid water, so ice floats

2) water has high surface tensions

3) water has high adhesion (attracted to other things) and high cohesion (attracted to itself)

4) water has high heat capacity, resulting in temperature stabilization

5) water has high boiling point and high heat of vaporization

What are some expression used to express the concentration of a solution?

g/mol, mOsm/L, meq/L, (v can be L or mL)

What is a mole?

Avogadro’s number (6.02×10²³)

our “dozen” of atoms

What is molarity?

• how can it be abbreviated?

number of moles of solute per liter

mol/L or M

How do the water properties work in the metric system?

1mL of water = 1g of water

How are the concentration of hydrogen ions (H+) expressed?

through pH units

The pH measurement is inversely proportional to?

• what is inversely proportional to this?

H+ concentration (as it increases pH decreases)

• -OH is inversely proportional to the concentration of hydrogen ions

How to calculate pH?

[H+] = 10^{-1 pH}

What is the normal pH range in human arterial blood?

• what range becomes concerning? why?

7.35 - 7.45

• 7.0 - 7.80 because small changes in pH present large change in H+ concentration, which has a significant effect on enzyme function

Define: Acid

• known as

• characterized by

molecules that ionize and release H+

• proton donors

• by a pH less than 7

Define: Bases

• known as

• characterized by

molecules that ionize and combine with H+

• proton acceptors

• by a pH greater than 7

Define: Buffers

prevent large increases in the [H+], helping to stabilize pH

Define: Salts

any substance that disassociates into an anion and cation that is NOT H+ or -OH

When acids and bases combine what do they form?

water and salt