Use This Description to Answer the Following Question

question 88

Multiple Choice

Use this description to answer the following question.
A major group of G-protein-coupled receptors contains seven transmembrane α helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosol side between helices 5 and 6 is usually substantially longer than the others.
-Based on the figure given below, which of these experimental treatments would increase the rate of sucrose transport into the cell?

• A) decreasing extracellular sucrose concentration
• B) decreasing extracellular pH
• C) decreasing cytoplasmic pH
• D) adding an inhibitor that blocks regeneration of ATP
• E) adding a substance that makes the membrane more permeable to hydrogen ions