Ch. 10 End of Chapter Questions

A key rate-limiting step in heme synthesis in suppression of: A. Aminolevulinate synthase B. Transferring mRNA synthesis C. Iron oxidase D. Protoporphyrin IX reductase

A

Normal adult Hb A contains which polypeptide chains? A. alpha and beta B. alpha and delta C. alpha and gamma D. alpha and epsilon

A

Which of the following forms of hemoglobin molecule has the lowest affinity for oxygen? A. Tense B. Relaxed C. Arterial D. Venous

A

How are the globin chain genes arranged? A. With alpha genes and beta genes on the same chromosome, including two alpha genes and two beta genes B. With alpha genes and beta genes on separate chromosomes, including two alpha genes on one chromosome and one beta gene on a different chromosome C. With alpha genes and beta genes on the same chromosome, including four alpha genes and four beta genes D. With alpha genes and beta genes on separate chromosomes, including four alpha genes on one chromosome and two beta genes on a different chromosome

B

Using the normal hemoglobin oxygenation curve in Figure 10-7 (pg 121), predict the postition of the oxygenation curve for methemoglobin. A. Shifted to the right of normal B. Shifted to the left of normal C. No change

B

Which of the following is a description of the structure of oxidized hemoglobin? A. Hemoglobin carrying oxygen on heme; synonymous with oxygenated hemoglobin B. Hemoglobin with iron in the ferric state (methemoglobin) and not able to carry oxygen C. Hemoglobin with iron in the ferric state so that carbon dioxide replaces oxygen in the heme structure D. Hemoglobin carrying carbon monoxide; hence the "oxidized" refers to the single oxygen

B

The nature of the interaction between 2,3-BPG and hemoglobin is that 2,3-BPG: A. Binds to the heme moiety, blocking the binding of oxygen B. Binds simultaneously with oxygen to ensure that it stays bound until it reaches the tissues, when both molecules are released from hemoglobin C. Binds to amino acids of the globin chain, contributing to a conformational change that inhibits oxygen from binding to heme D. Oxidizes hemoglobin iron, diminishing oxygen binding and promoting oxygen delivery to the tissues

C

What is the distribution of normal hemoglobins in adults? A. 80-90% Hb A, 5-10% Hb A2, 1-5% Hb F B. 80-90% Hb A2, 5-10% Hb A, 1-5% Hb F C. >95% Hb A, <3.5% Hb A2, 1-2% Hb F D. >90% Hb A, 5% Hb F, 1% Hb A2

C

A hemoglobin molecule is composed of: A. One heme molecule and four hemoglobin chains B. Ferrous iron, protoporphyrin IX, and a globin chain C. Protoporphyrin IX and four globin chains D. Four heme molecules and four globin chains

D

In the quaternary structure of hemoglobin, the globin chains associate into: A. alpha tetramers in some cells and beta tetramers in others B. A mixture of alpha and beta tetramers in each cell C. Alpha dimers and beta dimers D. Two alpha-beta dimers

D

The predominant hemoglobin found in a normal newborn is: A. Gower-1 B. Gower-2 C. A D. F

D