Oxygen Binding (General)

Equation for anaerobic respiration

Equation for aerboic respiration

Structure of lactate

Oxygen Dissociation curve for myoglobin

Absorption spectrum for deoxy and oxy myoglobin

Initial rate equation for myoglobin oxygen binding

Rearranged rate equation for myoglobin oxygen binding

Equation for fraction of occupied oxygen binding sites

Plot of fraction of binding sites versus oxygen concentration

Ligand properties of oxy-myoglobin

Ligand properties of deoxy-myoglobin

Why is myoglobin used over free ferrous heme

Free heme can bind O2 but the Fe 2+ is rapidly oxidised to Fe 3+ and ferric heme no longer binds O2 reversibly

What does the polypeptide chain in myoglobin allow for?

Prevents dimerization to the oxygen bridge intermediate

Confers special chemical properties on the heme / protein interior is analogous to an organic solvent environment

Transfer coefficient ratio in free ferrous heme

Transfer coefficient ratio in myoglobin

Why is the oxygen transfer coefficient for myoglobin higher?

In myoglobin, hydrogen bonding with histidine interferes with bonded oxygen, allowing it to be broken off easier

Steric hindrance from the double bond prevents the same from occuring for CO

What mutation can reduce efficacy of myoglobin

Distal Histidine mutation Mb(ValE7)

Which histidine is replaced in Mb(ValE7)

His64

Transfer coefficient ratio in Mb(ValE7)

Oxygen association curve for myoglobin and hemoglobin

Structure of hemoglobin

How many subunits in hemoglobin

How many residues in either subunit type

Between which subunits are interactions strongest

Oxygen saturation curve

Hemoglobin binding equation(s)

What does the sigmoidal saturation curve suggest about hemoglobin

K4 must be much bigger than K1

Thus oxygen binding is cooperative