Lecture #2

Question 1

type of interactions?

Answer 1

charge-charge
charge-dipole
dipole-dipole
charge-induced dipole
dipole-induced dipole
dispersion (van der waals)
hydrogen bond

Question 2

The macromolecules that participate in the structural and functional matrix of life are immense structures held together by ______

Answer 2

covalent bonds

Question 3

The complex 3-D architecture of the macromolecules is determined by

Answer 3

noncovalent interactions.

Noncovalent interactions are critically important determinants of biomolecular structure, stability, and function

Question 4

are proteins polymers?

Answer 4

yes, proteins are polymers of amino acids

Question 5

how are amino acids held together?

Answer 5

strong covalent amide peptide bonds.

The 3-D structure, and function of proteins are determined by a large number of noncovalent interactions.

Question 6

what do ions do when an electric current is passed through an ionic solution?

Answer 6

ions migrate toward the electrode of opposite polarity

Question 7

at what rate do ions migrate toward the electrode of opposite polarity

Answer 7

at a rate that is:

Proportional to the electrical field.

Inverseley proportional to the frictional drag of the ion (varies with ion size).

Question 8

The ionic mobilities of H3O+ and OH- are ______

Answer 8

anomalously large compared to other ions

Question 9

the ionic mobilities of H3O+ and OH- are anomalously large compared to other ions… why?

Answer 9

“proton hopping” – the mean life-time of a H3O+ ion is 10-12 seconds at 25°C.

Responsible for the observation that acid-base reactions are among the fastest to take place in aqueous solution.

Question 10

drugs have to be able to ________

Answer 10

1. ) Be soluble in aqueous environment.
2. ) In many cases, must be able to cross cell membranes.
3. ) Must be bioavailable (not broken down or effluxed)

Question 11

Lipinski’s “Rule of 5”… effective drugs must have:

Answer 11

1. ) Not more than 5 hydrogen bond donors (OH and NH groups)
2. ) Not more than 10 hydrogen bond acceptors (notably N and O)
3. ) A molecular weight under 500 g/mol
4. ) A partition coefficient log P less than 5

Question 12

water has a small or large tendency to form ions?

Answer 12

small.

H+
OH-
H3O+

Question 13

Amount of H3O+ and OH- in I L (liter) of pure water at 25°C

Answer 13

1 x 10-7 moles

concentrations are equal because of stoichiometry

Question 14

What is the molarity of water?

Answer 14

The molarity of water is equal to: the number of grams of water in a liter divided by the gram molecular weight of water… 55.5 M (molar

Question 15

at equilibrium how many mols of OH- and H+ are there?

Answer 15

10^-7 mol of H+, and 10^-7 mol of OH-

The decrease in [H2O] due to ionization is negligible.

Question 16

what is Kw, the “Ion Product” of Water?

Answer 16

Kw describes the concentration of H+ and OH- due to H2O dissociation
(1x10^-14)

Question 17

Organisms must maintain the pH inside cells and in most bodily fluids within

Answer 17

the narrow pH range of about 6.5 to 8.0.

The normal pH of human is 7.4.