can someone plz give me some background information on diffusion?
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diffusion is the movement of molecules from an area of higher concentration to an area of low concentration. diffusion occurs until the molecules reach a certain state called equilibrium.
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Osmosis and diffusion are both passive (do not require energy). They both involove the random movement of molecules from a region of high concentration to a region of low. \nWhen someone sprays perfume into the air, the perfume molecules diffuse around their enviroment, thats why you smell it at the other side of the room after a few seconds.\n\nThe differences are that osmosis is the movement of Water molecules from a high concentration to a low concentration through a semi permeable membrane.
165373
diffusion is when molecules move from greater concentration to lesser, to achieve equilibrium. osmosis is the diffusion of water molecules.
950301
Diffusion rate is generally directly proportional to the concentration gradient; in simple terms, to the difference in concentration across a membrane. This means the rate tends to decrease in a closed system where the concentrations are tending toward equality. You could get an average rate using your method, but the answer would depend on when your samples werre taken. There is a "rate constant" associated with diffusion. I couldn't find a definition on the web, but if it's similar to other rate constants it's expressed as the time it takes for the concentration gradient (or the diffusion rate) to decrease by a factor of 1/e, e being the base of natural logarithms, and 1/e roughly equal to 0.3679. Thus a shorter time constant means a faster rate constant. So you might consider determining the the time constant by finding two points where the concentrations are in that ratio and reporting the time between them.
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Try a rough DNA isolation, some things u need are detergent, lemons, and a sample like onion.\n\nSimple diffusion experiments with onions, salt, water, etc..
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I mean no disrespect, but as someone who understands Brownian motion, I am totally confused by the balloon, fans and stadium example. Let me try and simplify this for you and answer your question about an experiment.\n\nThe term Brownian motion (in honor of the botanist Robert Brown) refers to either "The physical phenomenon that minute particles immersed in a fluid move about randomly" \n\nThis is equally true for particles moving through air in a random motion while being bombarding by air molecules. The experient we did at school was as follows.\n\nTake a closed glass box with two chimney outlets. One chimney is covered by an oil soaked rag and the other left open. Light the oil rag and you will see the oil smoke moving through the glass box as the oil particles bounce off the air molecules in the box. Eventually you will see that the smoke fills the box eventhough no draft was added.\n\nThis is how most smells travel through a room without air flow.\n\nHope this helps
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Movement of substances across the cell membrane is the function of the 3 types of diffusion.\n\n\nThe generalized cell functions include movement of substances across the cell membrane, cell division to make new cells, and protein synthesis. \n\n\nMovement of substances across the cell membrane \nThe survival of the cell depends on maintaining the difference between extracellular and intracellular material. Mechanisms of movement across the cell membrane include simple diffusion, osmosis, filtration, active transport, endocytosis, and exocytosis. \n\nSimple diffusion is the movement of particles (solutes) from a region of higher solute concentration to a region of lower solute concentration. Osmosis is the diffusion of solvent or water molecules through a selectively permeable membrane. Filtration utilizes pressure to push substances through a membrane. Active transport moves substances against a concentration gradient from a region of lower concentration to a region of higher concentration. It requires a carrier molecule and uses energy. Endocytosis refers to the formation of vesicles to transfer particles and droplets from outside to inside the cell. Secretory vesicles are moved from the inside to the outside of the cell by exocytosis.
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Not sure what you mean... \nAn example of simple diffusion is that of steroid hormones which diffuse readily through the cell mebrane and reach their target molecules within the cell.\n\nFacilitated diffusion you have for example for the uptake of many hydrophilic/charged nutrients from the blood. The concentration of the nutrient is higher on the outside of the cell, yet it cannot simply diffuse through the membrane; it needs the help of transport proteins.\n\nActive transport means that the cell needs to import something uphill its gradient, using energy. The most profound example is the Na+/K+  ATPase which pumps Na+ out of the cell and K+ into the cell using ATP (both Na+ export and K+ import are uphill processes).\n\nA beautiful combination of passive and active transport is seen in the intenstinal epithelial cells. The concentration of glucose in the gut is lower than inside the cell. So the human body needs to consume energy and actively import glucose. This happens via a symporter that imports Na+ together with glucose. The import of Na+ is downhill so it releases energy which is used for the uptake of glucose. Once the glucose is inside the epithelial cell it will be passively exported to go to to the bloodstream.
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It would depend on several factors. Small, uncharged molecules can pass through the cell membrane through diffusion. When it is water, it is called osmosis. Diffusion can only occur into the cell when the concentration of the substance is greater outside the cell than within it, and likewise only out of the cell when the concetration is greater inside the cell than outside. This is called the concentration gradient.\n\nWhen the molecule is charged or is large (such as a chlorine ion or a lactose molecule), it requires active transport by carrier proteins. There are also carrier proteins that help to transport against the concentration gradient.\n\n[Edit] \nAfter thinking for a bit, I believe it would be pertinent to include something about the more complex methods of active transport.\n\nThere are two "directions" of the complex forms of active transport: in (endocytosis) and out (exocytosis).\n\nExocytosis is when a vesicle, after being released from the Golgi complex, fuses to the cell membrane, releasing the contents.\n\nEndocytosis is done by three main means: Phagocytosis, Pinocytosis, and Receptor-Mediated Endocytosis.\n\nPhagocytosis is the process of enveloping a large particle, such as how many unicellular organisms "eat" other organisms. The large particle comes in contact with the cell membrane, stimulating the formation of a vesicle. This vesicle then enters the cell and depending on the contents may fuse with a lysosome to help to digest it.\n\nPinocytosis also forms a vesicle, but differs from phagocytosis because it forms a much smaller vesicle.\n\nReceptor-mediated endocytosis is when particles that cannot normally enter the cell bond to receptor proteins embedded in the cell membrane. These proteins then congregate and form a vesicle. \n\nIn all forms of endocytosis and exocytosis, ATP is required for energy.
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http://science.howstuffworks.com/vdg2.htm
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easy, i just did this, diffusion would be passive transport, carbon dioxide going into and out of a cell, oxygen going into and out of a cell. Osmosis is the diffusion going into and out of something with WATER. Placing vegetables in water so they're fresher and crunchier. also puting a food dye in water, and the food dye sperading throughout the water.
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Geez, that's a beast of an assignment if you haven't even heard of these laws before.\n\nNone of these laws are recent, so any good encyclopedia should have lots of information about them.  Even Wikipedia, but always take wikipedia with a grain of salt, since it's nonprofessional and many professors don't accept citations from it.\n\nThe gas laws should be pretty well covered in an elementary chemistry textbook.  I really can't recall if such a book would cover Fickian diffusion, but Dalton's law and Henry's law should be in there as well.  If you have a chapter in your course textbook about blood chemistry, that might be a place to look, as Dalton's law deals with the partial pressure of gases, and Henry's law with the solubility of gases in liquids.  Fick's law would certainly be covered in any references about the lungs.
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Bernoulli Effects\n\nSee how to demonstrate it here --> http://www.physics.umn.edu/outreach/pforce/Bernoulli.html
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Diffusion is the flow of particles down the concentration gradient. Meaning that particles are flowing from an area of high concentration to an area of low concentration. Two examples are this occuring around your house are\n1. when you take a bubble bath. Even if you were to pour the bubbles in after the water stopped runnning the bubble mixture would still spread evenly throughout the water by simple diffusion.\n2. when you light a scented cande. The scent travels throughout the whole house because it travels from an area of high concentration (right above the candle) to the rest of the areas around the house that have low concentrations of the scent.\nGood? next time do your homework yourself :)
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1. brownian motion is the random motion of particles within a fluid (such as air, water, etc)\n\n3: Democritus, a Greek scientist/philosopher, coined the term atomos (plural atoma), meaning "cannot break down further" and "uncuttable." \n\n2: The atom was the basic building blocks of everything in the universe. Everything that was visible was made from atoms, and there were different shapes for different atoms, hence the many shapes in the world. Atoms were indestructable and always moving.\n\nGreek model of the atom: There were five kinds of atoms: earth, fire, wind, water, and "ether." Ether was everything that was created above the Earth's atmosphere. Ether did not have any distinct shape and was "pure and heavenly." The other four shared the same shape and were "flawed", but held different properties, derived in a bizarre way, but I guess appropriate for the time:\n    * Fire is both hot and dry\n    * Earth is both cold and dry\n    * Air is both hot and wet\n    * Water is both cold and wet\nFire would be able to burn Earth (hence wood used for fire) and Air is always above Water, and etc, etc. Everything on Earth was made from these 4 elements in different combinations, and so everything had different property variations.\n\nHope this helps.
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Two things make a difference here. The average distance that an individual particle is likely to move before it bangs into another particle and the speed at which the particles are moving.\n\nBecause the space between particles is so much larger in a gas than in a liquid at the same temperature, the "free path length" is longer in a gas and the diffusing substance is typically able to move further in a given period of time.  Therefore, gases diffuse through gases much more rapidly than liquids through liquids if all else is equal.\n\nFor any given combination, the hot gas or liquid substrate will provide more rapid diffusion compared to the cold one due to particle speed.\n\nYou need to check out Graham's Law of Diffusion if you want to get mathematical about this.
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Given that a certain type of molecule is small enough to permeate through the cell membrane, the most important factor influencing the rate of diffusion is the concentration gradient.  This is simply the difference in concentration levels of the substance between the outside and the inside of the cell.  The larger the difference in concentrations, the greater the rate of diffusion.