Chapter 6: 6.2 Thermodynamics

Question 1

What is the bilayer formation stabilized by?

Answer 1

The Hydrophobic Effect

Question 2

Describe:

Hydrophobic Effect

Answer 2

By preventing of nonpolar groups with water, the entropy of water is increased

Question 3

——— and ——– stability contribute to membrane formation

Answer 3

• Enthalpic
• Entropic

Question 4

What does ΔH represent in thermodynamics?

Answer 4

Enthalpic stability

Question 5

What does TΔS represent in thermodynamics?

Answer 5

Entropic stability

Question 6

Enthalpy refers to…

Answer 6

Bonds that are formed
* The more negative, the greater the stability

Question 7

Enthalpy refers to…

Answer 7

Molecular motion
* The more positive, the greater the stability

Question 8

What does ΔG represent in thermodynamics?

Answer 8

Stability

Question 9

How can stability (ΔG) be determined?

Answer 9

Using this formula:
ΔG = ΔH + (-TΔS)

Question 10

Bilayer formation is spontaneous when…

Answer 10

ΔG is negative

Question 11

Describe:

Energy change in Spontaneous Reactions

Answer 11

Initial state:
* Higher energy, less stable

Final state:
* Lower energy, more stable

Question 12

Describe:

Energy change in Non-Spontaneous Reactions

Answer 12

Final state:
* Higher energy, less stable

Initial state:
* Lower energy, more stable

Question 13

More freedom of movement mean:
1. More entropy
2. Less entropy

Answer 13

More entropy

Question 14

What is more entropy represented by in the equation for ΔG?

Answer 14

Bigger TΔS

Question 15

What effect does more entropy have on ΔG?

Answer 15

More negative ΔG

Question 16

Does more entropy result in thermodynamically favourable reactions?

Answer 16

Yes

Question 17

Why is there a large ΔS when bilayers form?

Answer 17

Before:
* Water molecules surround non-polar tails, their movement is restricted

After:
* Burying the hydrophobic tails away from water
* Allows more freedom of movement of the water molecules