Question

Answer all questions clearly and correctly

Find an oxygen binding curve for myoglobin in your textbook. How would you describe the shape of this 2. curve? 3. Explore the structure of hemoglobin using Proteopedia, Go to the Proteopedia site (http://www.proteopedia org/wiki/index.php/Main_Page) and search for hemoglobin. On the hemoglobin page, explore the structures and answer the tollowing questions. Note that you can rotate the hemoglobin molecule using your mouse and that clicking on green links changes the image of the structure. a. How many subunits does hemoglobin have? What are their conventional namesi? b. Identify the oxygen binding sites on hemoglobin. How many oxygens can one molecule of hemoglobin bind? How many oxygens can one subunit of hemoglobin bind? c. Identify the central cavity of hemoglobin. Is it the same or diferent than the oxygen binding site of hemoglobin? 4. Locate the picture of bisphosphosglycerate (BPG) binding to the central cavity of hemoglobin in your textbook or online. Bring a copy to class for use during the activity

Answer 1

The hemoglobin is present in circulating blood cells and provide oxygen to cells and tissues but it is also important to store the oxygen released from hemoglobin in capillaries and that is done by myoglobin. So it is very important for myoglobin to have higher affinity to oxygen than the hemoglobin that is why oxygen binding curve of hemoglobin is S shaped and for myoglobin it is hyperbolic. So, the graph shows that myoglobin is a better transporter than the hemoglobin and that makes this graph hyperbolic and not sigmoidal.

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