Chapter 7 - Key Concepts & Review Points

Question 1

Myoglobin, with its single heme prosthetic group, exhibits a ____________ O2-binding curve.

Answer 1

hyperbolic

Question 2

Hemoglobin can adopt the ________ (T) or ________ (R) conformation, which differ in O2-binding affinity.

Answer 2

deoxy

oxy

Question 3

Oxygen binding triggers conformation changes in hemoglobin so that oxygen bind to the protein cooperatively, yielding a ____________ binding curve.

Answer 3

sigmoidal

Question 4

____________ and ________ alter hemoglobin’s O2-binding affinity.

Answer 4

the Bohr effect

BPG

Question 5

____________ can change hemoglobin’s O2-binding properties and cause disease.

Answer 5

mutations

Question 6

____________, a monomeric heme-containing muscle protein, reversibly binds a single O2 molecule.

Answer 6

myoglobin

Question 7

____________, a tetramer with pseudo-D2 symmetry, has distinctly different conformations in its oxy and deoxy states.

Answer 7

hemoglobin

Question 8

Oxygen binds to hemoglobin in a(n) ____________ fashion, indicating cooperative binding.

Answer 8

sigmoidal

Question 9

O2 binding to a heme group induces a conformational change in the entire hemoglobin molecule that includes movements at the ____________ and the disruption of ____________. The result is a shift from the ________ state to the ________ state.

Answer 9

subunit interfaces
ion pairs
T
R

Question 10

CO2 promotes O2 dissociation from hemoglobin through the ____________. BPG ____________ hemoglobin’s O2 affinity by binding to deoxyhemoglobin.

Answer 10

Bohr effect

decreases

Question 11

The ____________ and ____________ models of allosterism explain how binding of a ligand at one site affects binding of another ligand at a different site.

Answer 11

symmetry

sequential

Question 12

Hemoglobin variants have revealed structure-function relationships. ____________ produces the symptons of sickle-cell anemia by forming rigid fibers in its ________ form.

Answer 12

Hemoglobin S

deoxy