In cotransport, one nutrient helps to transport another nutrient across the cell membrane. When a person drinks a large amount of water in a short time and consumes no or very little salt, the water absorbed from the intestine into the blood plasma will make blood plasma less concentrated (hypotonic) in relation to the fluid in the brain, so the water will move from the blood into the brain cells resulting in brain swelling. When a person with lactose intolerance drinks a lot of milk, the unabsorbed lactose will build up in the intestinal fluid, which will become hypertonic in relation to the fluid in the intestinal wall, so the fluid will start to move from the intestinal wall into the intestine and thus cause diarrhea. When you drink usual beverages, like water and fruit juices, the fluid in your intestine will become less concentrated (hypotonic) in relation to the blood plasma, so it will move across the intestinal wall into the blood, by the principle of osmosis. Osmosis is the main mechanism of water distribution in the body. Osmosis (from the Greek osmos = push) is the movement of water across the cell membranes from the solution with lower concentration (hypotonic solution) to the solution with higher concentration of solutes (hypertonic solution). Transport of glucose into the tissues is facilitated by the hormone insulin. Mineral ions, such as sodium, potassium, calcium and chloride, and larger molecules, such as glucose, amino acids and long-chain fatty acids, move in and out of the cells down their concentration gradient with the help of substance-specific carriers (proteins), which form channels or “pores” in the cell membranes.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |