Karteikarten
Biology AQA 3.1.3 Absorption
Karten in diesem Stapel (6)
- 1DiffusionThe passive net movement of molecules from a region of high concentration to low
- 2Active transportThe net movement of molecules with the use of ATP (energy) to move molecules from a region of low concentration to high
- 3Carrier proteinAn intrinsic protein across a plasma membrane stimulated by ATP
- 4Vili and microvilli are used in the absorption of carbohydrates in the small intestineThey have:
A large surface area
good blood supply
moist lining
close diffusion pathway
lots of capillaries - 5Diffusion in the Villi.1. Starch is hydrolysed to make glucose so diffusion can occur
2. glucose is a monosaccharide so can be absorbed
3.in the blood there is a low concentration of glucose
4. diffusion occurs across the epithelial in the blood - 6—1. NA+ actively transports out of epithelial cell into the blood by na+K+ pump (carrier protein)
2. due to NA+ entering the blood there is now a higher concentration in the lumen compared to epithelial
3. Na+ diffuses into the epithelial down the concentration gradient through a protein carrier
4. Na+ has to couple up with glucose to diffuse in, so glucose also enters the cell
5. glucose goes in the blood by facilitated diffusion
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- As Biology, AQA specification 3.1.3 absorption
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