Previously in Chem104:

•Standard Reduction Table (trends)

•Balancing Redox Equations (#1-easy) (#2-harder)

• Why the Correct Oxidation State Matters

Today in Chem104:

• It’s not all about Batteries:

•The Great Cycle of Energy

• Not at Standard?

• Membrane Potentials

Electron Transfer Reactions: NOT only for Metals!

NOT only about batteries!

Biology Is Run By Electron Transfer

5 Large Protein Complexes in Respiration

5 Complexes in Respiration Do Electron TransportUsing Electron Transfer Reactions(and pump H+ and make ATP…)

http://student.ccbcmd.edu/~gkaiser/biotutorials/energy/fg5.html

Detailed View of One Complex

The Great Cycle of Energy

Derived like this:

The Great Cycle of Energy

G

E Keq

G = -RTlnKG = -n F Erxn

lnK = (nF/RT)Erxn

The Great Cycle of Energy

Explains membrane potential …..

But first, we have to deal with Non-Standard Conditions: concentrations ≠ 1.0 M

Keyword: Nernst

TABLE OF STANDARD REDUCTION POTENTIALSTABLE OF STANDARD REDUCTION POTENTIALSTABLE OF STANDARD REDUCTION POTENTIALSTABLE OF STANDARD REDUCTION POTENTIALS

Eo (V)

Cu2+ + 2e- Cu +0.34

I2 + 2e- 2 I- +0.53

Zn2+ + 2e- Zn -0.76

strongerreducing ability

Ag+ + e- Ag +0.80

Fe3+ + e- Fe +0.772+

Pb2+ + 2e- Pb -0.13

Fe3+ + 2e- Fe -0.04

Al3+ + 3e- Al -1.66

Na+ + e- Na +2.71

K+ + e- K +2.93

2 H+ + 2e- H2 0.00

strongeroxidizing ability

The Great Cycle of Energy and Neuron Membrane PotentialsThe ideas covered in

Chapter 20 can be extended to understand a crucial concept in neurobiology, neurotransmittors and brain activity: membrane potential which is the electrical potential across a nerve axon cell membrane.

The Great Cycle of Energy and Neuron Membrane Potentials

The Great Cycle of Energy and Neuron Membrane Potentials

K Channels: what they look like