Answer Happy

1. Imagine that you are investigating the transepithelial transport of radioactive glucose. Intestinal epithelial cells are grown in culture to form a complete sheet so that the fluid bathing the apical domain (apical medium; side of the cells that normally face lumen of intestine) is completely separated from the fluid bathing the basolateral domain (basolateral medium; normally faces the insterstitial fluid/blood vessel). Radioactive (¹4C-labeled, glucose is added to the apical medium, and the appearance of radioactivity in the basolateral medium is monitored in terms of counts per minute per milliliter (cpm/ml), a measure of radioactivity per unit volume (see the top of the figure below for a visual depiction of the experimental design). What proteins are involved in glucose transport in the intestinal epithelial cell? Rubric(0.5): Recall from lecture proteins involved in this process (three proteins). Use the graphs provided and the information below to answer each question. Treatment 1: The apical medium and basolateral media each contain 150mM Nat. Treatment 2: The apical medium contains 1mM Nat and the basolateral medium contains 150mM Nat. Treatment 3: The apical medium contains 150mm Nat and the basolateral medium contains 1mM Nat. What is a likely explanation for the different results obtained in treatment 1 and 3 vs treatment 2? Rubric(0.5): Explain why treatment 1,3 were able to move glucose across the cells while treatment 2 could not. Radioactivity (cpm/ml) Time 1: Apical medium Basolateral medium Time 2: Apical medium Treatment 2 Basolateral medium Radioactivity in Basolateral Medium Treatment 1,3 Treatment 4 14 Time (min) in C-glucose Treatment 5 b. In additional studies the drug ouabain, which inhibits Na+/K+ ATPases, is included as noted. Treatment 4: The apical and basolateral media contain 150mm Na+ and the apical media contains ouabain. Treatment 5: The apical and basolateral media contain 150mm Na+ and the basolateral media contains ouabain. What is the likely explanation for the different results obtained in treatment 4 vs treatment 5? Rubric(0.5): Which side of the cell has Na+/K+ ATPase on the membrane?(0.25). Why does ouabain affect glucose movement in treatment 5?(0.25)