Answer:
A. True
B. False
C. False
D. True
E. False
Explanation:
A. The proximal histidine covalently binds iron.
This statement is true because the proximal histidine is covalently bonded to the fifth coordination position of iron in myoglobin
B. The distal histidine covalently binds oxygen.
This statement is false because the distal histidine interacts with the oxygen covalently bonded to the sixty coordination position of iron by means of a hydrogen bond not a covalent bond.
C. The distal histidine binds iron
This statement is false because the distal histidine is not bonded to iron but to oxygen but stabilizes the oxygen bonded to iron
D. Free heme binds CO with the Fe, C and O atoms in a linear array.
This statement is true because free heme has more affinity for CO than O2 as it has the least steric hindrance when the Fe, C, and O atoms lie in a straight line. On the other hand, when O2 binds to free heme, the axis of the oxygen molecule is positioned at an angle to the Fe-O bond thereby producing significant steric hindrance.
E. The iron in heme binds the oxygen atom of CO.
This statement is false because the iron in heme binds to the carbon atom, C, of CO rather than to oxygen atom.
The answer is true . hope this helps!
Answer: The phase change for A and B respectively is condensation, freezing.
Explanation:
A process in which gaseous state of a substance converts into liquid state is called condensation.
For example, conversion of steam into water.
A process in which liquid state of a substance converts into solid state is called freezing.
For example, conversion of liquid water into ice.
Thus, we can conclude that the phase change for A and B respectively is condensation and freezing.
