After entering intestinal epithelial cells and dissociating from the A2 polypeptide, the A1 peptide of cholera toxin catalyzes the ADP-ribosylation of the , inhibiting its activity. This leads to higher levels of ,which binds to and activates PKA. Phosphorylation of the CFTR Cl- channel by PKA leads to the unfortunate symptoms of cholera.

Which of the follow describes a disadvantage secondary sources have compared to primary sources?

The bacteria inside a tube worm would be analogous to what organism in the ocean ecosystem near the waters surface? a. photosynthetic algae b. shrimp c. clown fish d. parasitic lamprey

Define the apical impulse and describe its normal location, size, and duration. which abnormal conditions may affect the location of the apical impulse? explain the mechanism producing normal first and second heart sounds. describe the effect of respiration on the heart sounds. describe the characteristics of the first heart sound and its intensity at the apex of the heart and at the base. describe the characteristics of the second heart sound and its intensity at the apex of the heart and at the base.