BIOL 1201 : Bio Review Exam 2
Document Summary
The interior of a cell is different than its environment. How to defend the internal environment but still communicate with the external environment. ---species with a body temperature of 10c will have fluidity similar to a species with a body temp of 20c do not take fluidity too literally. Raised pigs wearing underwear in a hot room. Membrane fluidity adjusted by changing the ratio of unsaturated to saturated fatty acids. Only some types of molecules can pass through. Aquaporins: channel protein which facilitate water diffusion through the membrane. Work has to be done to move molecules down concentration gradient. From regions of high concentration to low concentration regions. When concentrations on both sides of a barrier are equal. -there is no net change in solute concentration. The net movement of water across or through a semi-permeable membrane. From higher (fewer solutes) water potential to lower water potential. Hypertonic soluitons will tend to gain water (explodes)
