Using bread as an example, describe the tasks of the various body systems in breaking down carbohydrate into glucose to fuel the cells' work
The various body systems must make glucose available to the cells, not all at once when it is eaten but at a steady rate all day. The largest of the digestible carbohydrate molecules, starch, requires the most extensive breakdown. Disaccharides, in contrast, need be split only once before they can be absorbed. The digestive system must first render the starch and disaccharides from the food into monosaccharides that can be absorbed through the cells lining the small intestine. The conversion of a bite of bread to nutrients for the body is completed when monosaccharides cross these cells and are washed away in a rush of circulating blood that carries them to the waiting liver. The absorbed carbohydrates (as monosaccharides: glucose, galactose, and fructose) travel in the bloodstream to the liver, which can convert fructose and galactose to glucose. The circulatory system transports the glucose and other products to the cells. Liver and muscle cells store circulating glucose as glycogen; all cells then split glucose for energy.
You might also like to view...
Fifty-eight-year-old Janet Englewood has been living with HIV for the past 15 years. Today she returns to her physician for a follow-up appointment. Which diet is most appropriate for Janet?
A) high kcalorie, high protein B) clear liquids with TPN C) regular D) no concentrated sweets, low saturated fat, low cholesterol
Which is true of nonprescription weight-loss products?
a. They must be approved by the FDA. b. They must be tested for safety and effectiveness by the manufacturer. c. They must list all active and nonactive ingredients on the label. d. Most have proved to be effective. e. Many have proved to be harmful.
E-mailing your legislators can be an effective way to communicate with them
a. True b. False Indicate whether the statement is true or false
Which element makes protein different from carbohydrate and fat?
A. carbon B. hydrogen C. nitrogen D. oxygen