Cholera Pre-lab

1. What is the difference between internal and external environments?

• Internal Environment: Refers to conditions inside the body, such as temperature and pH, regulated by homeostasis.

• External Environment: Refers to conditions outside the body, like temperature and humidity.

  b. How is the lumen of the alimentary canal or renal tubule classified?

  • The lumen of the alimentary canal is classified as external environment, while the lumen of the renal tubule is considered part of the internal environment in human physiology.

3. What are the 3 fluid compartments of the body?

   1- Intracellular fluid: Fluid inside cells.

   2- Extracellular fluid: Fluid outside cells.

   3- Interstitial fluid: Fluid between cells and blood vessels.

  4. Explain how the body can be in a state of osmotic equilibrium and chemical disequilibrium.

• Osmotic Equilibrium: When the concentration of solutes inside and outside the cell is equal, maintaining osmotic balance.

• Chemical Disequilibrium: Refers to different concentrations of ions and molecules inside and outside the cell, necessary for cellular functions.

b. Is this an example of homeostasis?

• Homeostasis: While osmotic equilibrium contributes to homeostasis, chemical disequilibrium can disrupt it.

  5. What is protein specificity?

  • protein's ability to bind to specific ligands or substrates due to its unique structure and active sites.

  b. How does this apply to signal molecules on cell membranes?

  • In the context of cell membranes, signal molecules interact with specific receptor proteins due to their complementary shapes, leading to cellular responses.

  c. How can the cell be prevented from reacting to signal molecules?

  • To prevent cells from signaling molecules, one can inhibit receptor-ligand interactions or disrupt downstream signaling pathways.

6. What is a typical (generic) signal pathway (chapter 6)? Make sure to list all the components.

   • Receptor: Receives signal

   • Transducer: Converts signal

   • Effector: Produces response

   • Second Messenger: Amplifies signal

   • Target: Executes response

   7. Briefly explain the difference between open channels and gated channels.

   • Open Channels: Allow ions to move freely across the membrane.

   • Gated Channels: Require a stimulus to open or close for ion movement.

   8. What is osmosis?

   • Osmosis is the movement of water molecules across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

   b. If the ion concentration increases or decreases, how will that dictate the direction water flows? -

   9. How does a saline IV (intravenous) solution in the blood rehydrate a patient?

   • Saline IV solution helps rehydrate patients by restoring electrolyte balance, increasing blood volume, and replenishing lost fluids, aiding in proper cellular function and hydration levels.

   10. How does an oral rehydration solution that contains electrolytes and glucose rehydrate a patient? (Hint: SGLT transporter).

   • The SGLT transporter, located in the small intestine helps absorb glucose and sodium, leading to water absorption and rehydration of the body.

   11. Can you think of any reasons or situations the IV or the oral rehydration solution would be better? - They provide a more direct and faster solution than others

   12. What is the mechanism of the cystic fibrosis transmembrane conductance regulator (CFTR channel)?

   • The CFTR channel is an ATP-gated chloride channel.

   • It regulates chloride and bicarbonate transport across epithelial cells.

   • Mutations in CFTR lead to impaired ion transport and cause cystic fibrosis.

   13. What is cholera?

   • Cholera is an infectious disease caused by the bacterium Vibrio cholerae, which affects the small intestine, leading to severe watery diarrhea and dehydration.

   14. How does it affect the CFTR?

   • Cholera toxin can activate the CFTR channel, causing excessive chloride and water secretion into the intestines, resulting in watery diarrhea.