Chapter 2- Water

Question 1

What is a H bond?

Answer 1

• electrostatic attraction between polarized molecules containing O-H, N-H ,or F-H

Question 2

What are electrostatic interactions?

Answer 2

-Attraction between oppositely charged ions or repulsion between similarly charged ions-up to 200kJ/mol

Question 3

How do biomolecules interact with water?

Answer 3

-H-bonding
-Electrostatic interactions

Question 4

What is salvation?

Answer 4

• the process when enthalpy is released when water-ion interactions form.
  -has negative delta H

Question 5

How does water interact with non polar, hydrocarbon?

Answer 5

van der Waals bonds: a short range very weak attractions. around 4kJ/mol

Question 6

What type of surfaces repel water?

Answer 6

-Superhydrophobic surfaces

Question 7

What are Amphipathic molecules?

Answer 7

They are molecules that contain both polar and non polar groups.

Question 8

A weak acid is a _______ of protons

Answer 8

-Donor

Question 9

A weak base is an __________ of protons

Answer 9

-Acceptor

Question 10

The weakest acids have the ______pKa’s

Answer 10

-Largest

Question 11

Biochemical reaction release H+ or OH-. How do cells deal with this? How do cells control pH?

Answer 11

-With Buffers

Question 12

What do titration curves indicate?

Answer 12

-The pH values of different mixtures of a weak acid and its conjugate base.

Question 13

Why do cells require buffers?

Answer 13

-Because high concentrations of H+ and OH- can BREAK covalent bonds and DECOMPOSE biomolecules.