Transport hemoglobin

FIGURE 5.13 Two basic types of biological transport are (a) transport within or between different cells or tissues and (b) transport into or out of cells. Proteins function in both of these phenomena. For example, the protein hemoglobin transports oxygen from the lungs to actively respiring tissues. Transport proteins of the other type are localized in cellular membranes, where they function in the uptake of specific nutrients, such as glucose (shown here) and amino acids, or the export of metabolites and waste products. 

After Releasing O2 at the Tissues, Hemoglobin Transports CO2 Protons to the Lungs... 

In addition to transporting Oj from the lungs to peripheral tissues, hemoglobin transports CO2, the byproduct of respiration, and protons from peripheral tissues to the lungs. Hemoglobin carries CO2 as carbamates formed with the amino terminal nitrogens of the polypeptide chains. 

Figure 3.4 Hemoglobin transports oxygen and has a quaternary structure that shows how the chains arrange to form the molecule. As shown above, it consists of four polypeptide chains—two identical alpha globin (blue) and two identical beta globin (yellow)—each carrying a heme group (white) with a central iron atom, which bonds to oxygen. The green structure represents the amino acid glutamic acid at residue 6 on the beta chain.

Hemoglobin Transports Oxygen Effieiently by Binding Oxygen Cooperatively... 

Enzymes like PTE rely upon a special kind of molecular assistance to do their jobs efficiently. Metals such as iron, zinc, and copper all perform vital roles in some of the enzymatic reactions that fuel the body s metabolism. Iron, for instance, helps the protein hemoglobin transport oxygen to organs in the body. Many metals act to stabilize the shapes of enzymes. But the body s handling of metals—some of which can be highly toxic in excessive amounts—is a tricky business. In some cases, cells exert exquisitely tight control, assuring that only one or two free metal atoms are present inside an individual cell. 

HEMOGLOBIN TRANSPORTS OXYGEN EFFICIENTLY BY BINDING OXYGEN COOPERATIVELY... 

Review Table 21.18, which lists some important biological functions associated with different first-row transition metals. The transport of O2 in the blood is carried out by hemoglobin. Briefly explain how hemoglobin transports O2 in the blood. 

Hemoglobin Transport of Oxygen from the Lungs to the Tissues, in Two Parts... 

The third and fourth oxygens bind more easily yet, to complete loading of the hemoglobin transport system with its oxygen cargo. 

In particular, in this chapter we examine a number of protein-based biological systems that can present excesses of insolubility or solubility. Some of these, for example, muscle contraction and hemoglobin transport of oxygen. 

Hemoglobin Transport of Oxygen by Positioning the Cusp of Insolubility Through Control of Intersubunit Hydrophobic Association/Dissociation... 

Transport Carry essential substances throughout the body Hemoglobin transports oxygen. Lipoproteins transport lipids. 

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