Chapter 2

Question 1

Brownian Motion

Answer 1

Is the random movement of molecules in a fluid or gas powered by the background thermal energy.

Question 2

Water is said to be polar but uncharged, how is that possible?

Answer 2

Water is polar in that the hydrogen atom bear a partial positive charge, whereas the oxygen atom has a partial negative charge owing to the electronegative nature of the oxygen atom, however, the total charge on the molecule is zero, that is, the positive charges are equal to the negative charges

Question 3

Why are weak bonds important in biochemistry?

Answer 3

Many weak bonds allow for highly specific yet transient interactions

Question 4

What are the common types of weak bonds important in biochemistry? How does water affect each of these bonds?

Answer 4

1. Ionic bonds
2. Hydrogen Bonds

Water disrupts ionic and hydrogen bonds

3. Van der walls interactions

Because Van der walls interactions interactions are common between hydrophobic groups, water strengthens these bonds by facilitating their formation through the hydrophobic effect

Question 5

In liquid water, each molecule is hydrogen bonded to a proximately 3.4 molecules of water. What affected freezing water have on the number of hydrogen bonds? Heating water?

Answer 5

Lowering the temperature would reduce the motion of the water molecules and allow the formation of more hydrogen bonds (ice is hydrogen bonded to 3.7 molecules of water)

Heating the water makes fewer hydrogen bonds form, (at 100°C, a molecule of water is hydrogen bonded to 3.2 water molecules).