what will happen to a cell if a cell is permeable to all substances?
451453
The cell wouldn't function because important chemicals would leak out and destructive chemicals would come in.
380794
Basically by osmosis. The cell absorbs nutrients and oxygen through the cell wall from the blood circulating in the capillaries. The oxygen is absorbed by the body in an exchange in the lungs and nutrients are absorbed through the small and large intestine and they all travel in the blood stream to the cells.
723400
Water is actually the main component of the cytoplasm of a cel, as well as being used in energy production cycles.  As a small, non-polar molecule, water enters the cell by way of passive diffusion called osmosis.  The semi-permeable membrane means that not just anything can cross it.  The only things that can passively cross the membrane are molecules that are, like water, small and non-polar.  Anything else must be actively transported in, or have a channel protein.
44587
That depends on the type of cell and its function.
941524
Gee...broad question...depends what ur transporting.\ne.g. for gases u need a semi-permeable membrane, a thin membrane, a gradient, a moist/mucus surface
384772
Difusion is the movement of particles from an area of high concentration to an area of low concentration, until they are apread out evenly.\n\nExamples for diffusion: \nThe alveoli are well adapted for diffusion of gases, \nthey have a large surface area\nthey are moist, so gases can dissolve\nthey have thin walls\nand a good blood supply.\n\nThe small intestine is specialised for absorption. \nIt has: \nA thin lining\na good blood supply\na very large surface area.\n\nOsmosis is the diffusion of water molecules from a dilute solution to a more concentrated solution through a partially permeable membrane.\n\nA partially permeable membrane allows water molecules to pass through, but not solute molecules.\n\nWhen a plant cells are full of water they are turgid.\nThis rigidity or turgour gives the plant support\nCells are able to absorb some substances against a concentration gradient.\n\nActive transport needs energy from respiration. \n\nActive transport....\nNot all sustances pass into cells by diffusion or osmosis. Some substances are absorbed against a concentration gradient. But to do this energy is needed and it comes from respiration. This process is called ACTIVE TRANSPORT.\nExample of active transport are:\nThe uptake of ions by root hair cells from the soil, where they are in very dilute solution;\nthe uptake of sugar molecules into the small intestine;\nthe re-absorbtion of useful ions in the nephrons of the kidneys.
733835
Some diffuse across the membrane.  The membrane is semipermeable  meaning that it allows some things to diffuse accross and some cannot pass at all.  example: Water will diffuse accross.\n\nTheir a various channels in the membrane that will transport items into and out of a cell even against a concentration gradient.\nTheir are calcium and sodium channels.\n\nSome are engulfed by animal cells: example:  white blood cells will engulf bacteria:phagocytossis
1047759
Cells have openings on their outer membrane - ion pumps. The pumps regulate the concentration of sodium and potassium ions in the cell. The difference in ions in and out of the cell creates an electric potential across the membrane allowing a nerve impulse to propagate along its length. Jens C. Skou won the 1997 Nobel Prize for work in this area. Several ion pumps have now ben described.
771971
Cell membrane, or phospholipid bi-layer.
780599
Water equalizes the pressure between the outside and the inside of the cell wall, so it doesn't become damaged.  It also is the transport medium for nutrients coming in, and waste exiting.
779752
A living cell (like a cell from the liver, lungs, brain, etc...) will die soon after it was removed from its original "place" (liver, lungs, brain, etc.) as it has no more nutrients-supply (by blood venes, for example!) except it is kept in an artificial environment, a culture medium, which is suited to it's very specific needs.\n\nA living cell that is an organism needs a special suited environment, too (a diatom won't survive in the desert...). But it is not depending on an EXTERNAL supply of nutrients, as it "searches" its nutrients on its own. Bacteria, for example, don't need blood venes to grow in order to make cell division, they just need an environment which supplies all the needed nutrients. That's why bacteria can grow nearly everywhere, while lung cells  would die short after you dispersed them on an old dank sponge.\n\nHope I helped you. Excuse my English, please, it's not my first language. Good luck for tomorrow! ;-)
37484
All cells have membrane-spanning proteins that serve as channels.  They can move materials across the cell membrane, either in or out, by passive diffusion, active transport (ie ATP-consuming energy-burning motors that sort materials against a chemical gradient) or facilitated transport (ie coupled transport systems where the movement of one chemical down a chemical gradient is coupled with the transport of another chemical up a gradient).  Some combination of these methods is used to transport wastes from the bacterial cell.\n\nIn eukaryotic cells (ie not bacteria, but possibly including single-celled protists and fungi) there can also be excretion of materials by the means of small vessicles made of the same lipid bilayer that the membrane is made of.  When these vessicles fuse to the cell membrane, the contents spill out, and the vessicle lipids become part of the cell membrane.
900184
some cells to take in more. Cell permiablility.\n\nhttp://www.answers.com/topic/cell-permeability
559184
B) Membrane-bound organelles\nThe procariotic cells are like a water-filled baloon, they are just a cover with water and other things (of course, this is only an example), while eukaryotic cells have compartiments.\nEvery cell has DNA, that's the way information is passed from cell to cell when they reproduce.\nRibosomes are important for producing proteins, every cell has to have them, even if with time they lose them.\nCytoplasm is the 75% of every cell, it's basically water, proteins and other things.
283526
Cell bio would encompass all things on a cellular level.\nUsually organisms with a "life of their own".\nMolecular bio goes further into the atomic level.\nEg: a molecule of water (H2O) consists of 3 atoms. take a H away and you have Hydrogen peroxide(HO). A cell is usually made up of many different molecules when added together, make an organism like a liver cell, cancer cell, stem cell,etc...
72954
The plasma membrane or the cell membrane is semi-permeable.Its function is to regulate the exchange of materials between the cytoplasm and extracellular fluid.
247317
There may be some resistant mammalian cells, but generally 70% ethanol will kill-not because of dehydration, but because the solution will dissolve the lipids in the cell membrane, leaving only the protein scaffolding-thus the cell will completely lose it's ionic and chemical balance.