Active Transport Essay

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The Effect of Active Transport on the Movement of Glucose Against the Concentration Gradient within the Small Intestine of a Rat
Introduction
The movement of substances across the cell membrane occurs in many ways, including transport by carrier proteins, also known as active transport (Barman et al. 1986). Active transport involves the movement of molecules through the cell membrane against a concentration gradient with the help of a carrier protein utilizing ATP energy. (Barman et al. 1986). This differs from processes like diffusion where the molecules or ions do not move against their concentration gradient. The process of active transport results in the accumulation of ions or molecules either inside or outside of the cell in an area
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It is divided into three sections: the duodenum, the jejunum, and the ileum. The duodenum is the first section in which solutes pass through for absorption and the ileum is the final place for absorption in the small intestine. The inner surface of the small intestine appears to be folded, but is lined with finger-like projections called villi (Crane 1979). Along the villus one will find microvilli, tiny projections lined with epithelial cells capable of absorbing solutes in the process of digestion (Crane 1979). The microvilli are in close proximity of the blood and lymph which pick up the nutrients in order to distribute them to the rest of the body (Crane 1979).
Active transport will affect the absorption of solutes in the small intestine. The greatest change in weight for the small intestine will occur in the duodenum, the section closest to the mouth. The least amount of change in weight will occur in the ileum, the section of the small intestine closest to the anus.
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The loop was tied firmly to close off the lumen. A rod was inserted into the tied off end. The wall of the intestine right after the tied knot was gently moved over the rod so that the wall doubled over itself. The wall of the intestine was doubled over until the rod showed through the opposite end. The intestine was covered with a closed sleeve of the intestine with the mucosal surface outward. The eversion process was continued until the entire intestinal segment has been turned inside out. The rod was pulled out. The outside of the inverted intestine was rinsed with Tyrode’s. A plastic pipette, which was filled with Tyrode’s, was slipped into the opposite end of the segment and held with a single string knot. The segment was filled with solution and the pipette was removed from the end of the intestine. At the same time of the pipette removal, the loop of the thread was secured to seal the sac. The knot was secured with another knot. The sac was handled by the threads. The mucosal surface was not touched again. A piece of masking tape was attached to the thread and marked with the group name. The sac was weighed and the data was recorded.The steps above were repeated for the second rat intestine sample. When each of the two sacs were completed, they were placed in a beaker containing Tyrode’s. The osmotic concentration difference between the outer mucosal side of the sac and

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