Cholera kills over 100,000 people each year worldwide due to diarrhea. The cholera toxin opens the C… Show more Cholera kills over 100,000 people each year worldwide due to diarrhea. The cholera toxin opens the CFTR chloride channel in the intestines, so that sufferers lose chloride, sodium and massive amounts of water. On the other hand, the same CFTR channel is mutated in cystic fibrosis patients. With activity too LOW, they lack chloride flow and mucus builds up in the lungs. This illustrates the importance of precise control of channel opening, known as ____________regulation. A.gated B.ungated C.passive Estrogen and testosterone are structurally related to cholesterol. Based on what you have learned about cholesterol, predict how these steroid hormones signal to the cell. A.They are phagocytosed, degraded, and then released into the cell. B.They make the membrane so fluid that small pores appear, allowing them to pass through. C.They bind to receptors on the outside of the membrane, which then activate an intracellular signaling cascade. D.They diffuse directly through the plasma membrane and into the cell. Membrane proteins are able to cross because sections are composed of A.polar amino acids B.hydrophilic phosphate regions C.hydrophilic amino acids. D.nonpolar phosphate regions E.hydrophobic amino acids • Show less60