Chapter 10 - Hemoglobin Metabolism

Question 1

A hemoglobin molecule is composed of:

Answer 1

d. Four heme molecules and four globin chains

Question 2

Normal adult Hb A contains which polypeptide chains?

Answer 2

a. α and β

Question 3

A key rate-limiting step in heme synthesis is suppression of:

Answer 3

a. Aminolevulinate synthase

Question 4

Which of the following forms of hemoglobin molecule has the lowest affinity for oxygen?

Answer 4

a. Tense

Question 5

Using the normal hemoglobin-oxygen dissociation curve in Figure 10-7 for reference, predict the position of the curve when there is a decrease in pH.

Answer 5

a. Shifted to the right of normal with decreased oxygen affinity

Question 6

The predominant hemoglobin found in a healthy newborn is:

Answer 6

d. F

Question 7

What is the normal distribution of hemoglobins in healthy adults?

Answer 7

c. .95% Hb A, ,3.5% Hb A2, 1% to 2% Hb F

Question 8

Which of the following is a description of the structure of
oxidized hemoglobin?

Answer 8

b. Hemoglobin with iron in the ferric state (methemoglobin) and not able to carry oxygen

Question 9

In the quaternary structure of hemoglobin, the globin
chains associate into:

Answer 9

d. Two αβ dimers

Question 10

How are the globin chain genes arranged?

Answer 10

b. With α genes and β genes on separate chromosomes, including two a genes on one chromosome and one β gene on a different chromosome

Question 11

The nature of the interaction between 2,3-BPG and hemoglobin is that 2,3-BPG

Answer 11

c. Binds to amino acids of the globin chain, contributing to a conformational change that inhibits oxygen from binding to heme