Question

active transport
in developing countries, contamination of food and water from cholera is a serious problem. cholera is a disease caused by the bacterium vibrio cholerae. cholera causes severe diarrhea, which leads to the loss of large amounts of water per day. cholera works by releasing a toxin that attaches to the lining of the digestive system. this causes the release of sodium and chlorine into the intestinal lumen (space inside intestines).

1. explain how the release of sodium and chlorine would lead to a loss of water in the intestines.
2. in the intestinal cells there are sodium - glucose transporters. knowing this, explain why doctors give patients recovering from cholera a sodium - glucose solution to drink.
3. the image to the right illustrates a portion of a neuron. what process is occurring?
4. the image to the right illustrates a portion of a white blood cell. what process is occurring?

Explanation:

1. When sodium and chlorine are released into the intestinal lumen, it creates a higher solute concentration there compared to the cells. Water moves from an area of lower solute concentration (inside cells) to an area of higher solute concentration (intestinal lumen) by osmosis, leading to water loss from the intestines.
2. Sodium - glucose transporters in intestinal cells can co - transport sodium and glucose into the cells. By giving a sodium - glucose solution, the sodium and glucose are absorbed together. This helps to increase the uptake of sodium which can then help with water reabsorption due to osmosis, as water follows the movement of sodium into the cells, thus helping patients recovering from cholera to rehydrate.
3. The image of the neuron likely shows exocytosis as vesicles are fusing with the cell membrane and releasing their contents outside the cell. This is common for neurons to release neurotransmitters.
4. The image of the white blood cell likely shows phagocytosis. White blood cells are known to engulf foreign particles or pathogens by extending their cell membrane around the target and internalizing it.

Answer:

1. Water moves into the intestinal lumen by osmosis due to higher solute concentration there after sodium and chlorine release.
2. Sodium - glucose co - transport helps with sodium uptake and subsequent water reabsorption for rehydration.
3. Exocytosis
4. Phagocytosis