Chapter 1, Problem 4SC

The hormone insulin enhances the transport of glucose (sugar) from the blood into most body cells. Its secretion is controlled by a negative-feedback system between the concentration of glucose in the blood and the insulin-secreting cells. Therefore, which of the following statements is correct? A decrease in blood glucose concentration stimulates insulin secretion, which in turn further towers blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn lowers blood glucose concentration. A decrease in blood glucose concentration stimulates insulin secretion, which in turn increases blood glucose concentration. An increase in blood glucose concentration stimulates insulin secretion, which in turn further increases blood glucose concentration. None of the preceding is correct.

In a popular magazine article the author reports health benefits attributed to a particular dietary supplement. What kinds of evidence should the article cite to help you decide whether the information is likely to be accurate?

Does physical exercise to increase muscle mass involve anabolic and/or catabolic processes? Give evidence for your answer.