Chapter 7 Review

Question 1

In terrestrial animals, myoglobin…

Answer 1

• Increases O2 solubility

- Promotes O2 diffusion into tissue

Question 2

In marine animals, myoglobin…

Answer 2

• Promotes O2 diffusion
• 10x amount of Mb present
• Functions in O2 storage

Question 3

Structure of the Sperm Whale myoglobin was discovered by ___________. It was the first _____ of a protein.

Answer 3

John Kudrow (1959) ; protein crystallography

Question 4

Myoglobin is known for two important jobs

Answer 4

1) Binding and releasing O2

2) Helps diffuse CO2 throughout the body

Question 5

Sperm Whale myoglobin is a ___ protein. It has a total of _________. Heme (protoporphyrin 9). Fe(II) is the metal in the middle. Contains ________ and _________.

Answer 5

Pyroles and histidine residues

Question 6

What is the proximal histidine?

Answer 6

The histidine attached to the Fe atom

Question 7

Can Fe (II) convert to Fe (III)?

Answer 7

Yes, when Fe(II) becomes Fe(III), this means that an e- is lost. Once Fe (III) is formed, it can’t bind to oxygen and myoglobin is not useful anymore.

Question 8

The protein _________the heme _______ and non-oxygen things.

Answer 8

protects ; from oxidation

Question 9

Ka is __________ to Kd.

Answer 9

inversely proportional

Question 10

Why do partial pressure values matter?

Answer 10

Pressure helps dissolve O2 into the blood.

Question 11

YO2 = (PO2)/(Kd+pO2)

Answer 11

Dalton’s Law of Partial Pressure

Question 12

YO2 vs. PO2 hyperbolic curve means

Answer 12

myoglobin binding

Question 13

The greater the partial pressure, the ________ the solubility.

Answer 13

greater

Question 14

Fraction bond is equal to _____.

Answer 14

Dissociation constant

Question 15

Lower affinity for oxygen on a myoglobin partial pressure graph will cause the graph to

Answer 15

move to the right and become more shallow

Question 16

The quaternary structure of hemoglobin is ________.

Answer 16

heterodimer

Question 17

Oxygenation of a heme group means

Answer 17

oxygen is binding to the heme group

Question 18

When Fe(II)-heme complex is oxygenated

Answer 18

• The electronic state is altered

- The color changes from dark purple to red.

Question 19

Define fractional saturation

Answer 19

the O2 dissociation of myoglobin. The fraction of O2-binding sites occupied by O2. (Value ranges from 0 ,or no O2 bound, to 1, or all the binding sites of all the myoglobin molecules are occupied)

Question 20

low pO2 of myoglobin means

Answer 20

little O2 binds to the myoglobin

Question 21

high pO2 of myoglobin means

Answer 21

virtually all O@_BINDING SITES ARE OCCUPIED> Myoglobin is saturated with O2.

Question 22

As pO2 of myoglobin increases, ______ O2 binds to the myoglobin.

Answer 22

more

Question 23

p50

Answer 23

the oxygen pressure at which myoglobin is 50% saturated

Question 24

p50 of myoglobin

Answer 24

2.8 torr

Question 25

Myoglobin brings oxygen to the ________ of ________ cells.

Answer 25

capillaries ; muscle

Question 26

Hemoglobin is a _____. It has ____ C2 symmetry and ____ symmetry.

Answer 26

α2β2 tetramer ; exact ; pseudo-D symmetry

Question 27

Hemoglobin has a _______ quaternary structure.

Answer 27

heterodimer

Question 28

Hemoglobin is made of _____ subunits: 2 _ and 2 _

Answer 28

4 ; α ; β

Question 29

When oxygen binds to hemoglobin, the ______ of hemoglobin changes.

Answer 29

structure

Question 30

T-State

Answer 30

Deoxy hemoglobin, low affinity for oxygen

Question 31

R-State

Answer 31

Oxy hemoglobin, high affinity for oxygen

Question 32

_____ degree rotation causes R-state to go back to T-state.

Answer 32

15

Question 33

Hemoglobin partial pressure curve is ______.

Answer 33

Sigmoidal

Question 34

Define cooperativity.

Answer 34

• The proteins “work” together.

Question 35

Define allosteric effect

Answer 35

A small molecule whose binding to a protein affects the function of another site on the protein.

Question 36

In hemoglobin, _____ prevents the release of oxygen.

Answer 36

cooperativity

Question 37

____________ transports the oxygen from the hemoglobin to the cell.

Answer 37

myoglobin

Question 38

What prevents veins busting from the built up pressure from CO2 when exercising?

Answer 38

carbonic anhydrase promotes the forward reaction of CO2 + H2O H+ + HCO3-

Question 39

At higher pH, hemoglobin _______ its oxygen

Answer 39

releases

Question 40

What is Allostery?

Answer 40

Communication between subunits.

Question 41

Symmetry Model of Allosterism

Answer 41

• T-state and R-state are always talking back and forth. They are in the same state.
• A model of allosteric behavior in which all subunits of an oligomeric protein are constrained to change conformation in a concerted manner so as to maintain the symmetry of the oligomer.

Question 42

Sequential Model of Allosterism

Answer 42

• T-state goes to R-state and reverse.
• A model of allosteric behavior in which the subunits of an oligomeric protein change conformation in a stepwise manner as the number of bound ligands increases.

Question 43

A normal RBC has Pro-Glu-Glu. A sickle-cell RBC will have the mutation __________.

Answer 43

Pro-Val-Glu

Question 44

Vaccines stimulate _____.

Answer 44

T-cells

Question 45

Antibody response is part of the _______ immune response.

Answer 45

humoral

Question 46

Antibodies (aka immunoglobins) have ________ bonds. ___ C-termini. 2 _____chains and 2 _______ chains.

Answer 46

Disulfide bonds ; 4 ; heavy and light

Question 47

Fab

Answer 47

“Arms” of the antibody. Antigen binding; variable binding region (antigen coded by hypermutatable region.

Question 48

What is Neutralization in immunology?

Answer 48

Antibodies surround the antigen to prevent the virus from binding to the host cell.