CH3 Key Concepts

Myoglobin is what type of protein?

oxygen storage protein

Hemoglobin is what type of protein?

oxygen carrying protein

What allows O2 binding in myoglobin?

heme

Iron forms how many bonds in myoglobin?

6 bonds

What H-bonds w/ O2 to stabilize complex?

distal histidine

What is a potent competitor in myoglobin?

CO

Hemoglobin has what type of structure?

tetramer

In hemoglobin, Sigmoid shows that binding at one site increases or decreases the likelihood of binding at another site.

increases

What are the 3 effects of cooperative binding in hemoglobin?

1. efficient O2 transport

2. more complete delivery of O2 to tissues

3. O2 is delivered to tissues where it is most needed

When O2 binds to hemoglobin, what does it cause the dimers to do?

rotate

T state refers to deoxyhemoglobin or oxyhemoglobin?

deoxyhemoglobin

R state refers to deoxyhemoglobin or oxyhemoglobin?

oxyhemoglobin

In what state are O2 binding sites free of strain and bind to O2 w/ higher affinity?

R state

When iron atom in hemoglobin moves, what also moves w/ it?

proximal histidine

What is the positive allosteric effectors?

O2

What are the negative allosteric effectors?

2,3-BPG, Protons, CO2

What does not show cooperative O2 binding?

Purified hemoglobin

What is The Bohr Effect?

regulation og O2 binding by H+ & CO2

As pH goes down from 7.4, what happens to O2 affinity?

it goes down

As hemoglobin goes to a more acidic environment, does more or less O2 release?

more

What can stimulate O2 release?

CO2

Does CO2 lower or raise pH?

lower (makes it more acidic)