What are the signs and symptoms of sickle-cell anemia and what causes it?
What will be an ideal response?
The sequence of amino acids in each protein determines its shape, which supports a specific function. An error in the amino acid sequence results in an altered protein—sometimes with dramatic consequences. The protein hemoglobin offers one example of such a genetic variation. In a person with sickle-cell anemia, two of hemoglobin's four polypeptide chains have the normal sequence of amino acids, but the other two chains do not—they have the amino acid valine in a position that is normally occupied by glutamic acid. This single alteration in the amino acid sequence changes the characteristics and shape of hemoglobin so much that it loses its ability to carry oxygen effectively. The red blood cells filled with this abnormal hemoglobin stiffen into elongated sickle, or crescent, shapes instead of maintaining their normal pliable disc shape—hence the name, sickle-cell anemia. Sickle-cell anemia raises energy needs, causes many medical problems, and can be fatal. Caring for people with sickle-cell anemia includes diligent attention to factors such as infection, stress, and dehydration, all of which can trigger a crisis.
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How do the pancreas and small intestine function together in the process of digestion?
A. The pancreas produces hydrochloric acid (HCl) and releases it into the small intestine. B. The pancreas stores inactive digestive enzymes, and they are activated in the small intestine. C. The pancreas produces bile, which travels to the small intestine for fat emulsification. D. The pancreas produces insulin, which helps break apart carbohydrates in the small intestine.
The building blocks of proteins are called amino acids
Indicate whether the statement is true or false
Disparities in health status and life expectancy among countries in the global community can be attributed to all of the following EXCEPT:
a. differences in financial resources. b. differences in food preferences. c. differences in population growth. d. rates of malnutrition.
Which of the following would be considered a component of health-related fitness?
A. Power B. Flexibility C. Skill D. Speed