means that it only allows certain molecules or ions to get in or to get out of the cell. There are three types of movement of particals across the cell: diffusion(and also facilitated diffusion)‚ osmosis and active transport. Diffusion and osmosis are passive movements and they don’t require any energy. Active transport requires ATP energy. OSMOSIS is the passive movement of water molecules across a partially permeable (semipermeable) membrane‚ from a region of lower solute concentration to a region
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Scientific Paper on Diffusion 2 ABSTRACT The effect of molecular weight on the rate of diffusion was assessed using two tests: the glass tube test and the agar-water gel test. In the glass tube set-up‚ two cotton plugs soaked in two different substances (HCl and NH4OH) were inserted into the two ends of the glass tube. The substance with the lighter molecular weight value (NH4OH‚ M = 35.0459 g/mole) diffused at a faster rate (dAve = 25.8cm)‚ resulting in the formation of a white ring around the
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and West Asia received outside influences and effectively spread their religions. Economically‚ they interacted with other regions to enhance their societies. Thus‚ the social‚ cultural and economic aspects helped give rise to interaction and diffusion of the civilizations. Both societies emphasized male-dominance‚ but they were structured differently. Women in both regions had little power and were seen as subordinates. The strict patriarchy demonstrates the strength and control of the civilization
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A summary of Diffusion of Innovations Les Robinson Fully revised and rewritten Jan 2009 Diffusion of Innovations seeks to explain how innovations are taken up in a population. An innovation is an idea‚ behaviour‚ or object that is perceived as new by its audience. Diffusion of Innovations offers three valuable insights into the process of social change: - What qualities make an innovation spread successfully. - The importance of peer-peer conversations and peer networks.
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"Diffusion - How atoms move through solids" Diffusion means mass transport by atomic motion. The mechanisms of Gases & Liquids is known as random (Brownian) motion and for solids is known vacancy diffusion or interstitial diffusion. Simply we can define diffusion as‚ the movement of particles in a solid from an area of high concentration to an area of low concentration‚ resulting in the uniform distribution of the substance. (Diffusion chapter 5‚ 2008‚ p.1) Ronald D. Kriz(1999) suggests that
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the aim and background information 2.1. Diffusion is the spontaneous kinetic movement by which molecules move from an area of a high concentration to an area of low concentration. Diffusion continues until it reaches equilibrium. Osmosis is similar to Diffusion but it’s the process in which water moves across a semi-permeable membrane and goes to the higher concentration of solute.1 2.2. Important factors to Osmosis and Diffusion include Temperature‚ Concentration and Surface area
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#2 Elodea and Photosynthesis by __________________ Name:_____________________ Class:_____________________ Teacher:_____________________ Date:_____________________ Elodea and Photosynthesis Introduction: Photosynthetic organisms (cyanobacteria) first evolved about 3.5 billion years ago and are the oldest know fossils on Earth. Cyanobacteria live in water‚ can manufacture their own food‚ and are one of the most important groups of bacteria on Earth. The Cyanobacteria have been important
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The Effect of Molecular Weight and Time on the Diffusion Rate of Potassium Permanganate‚ Potassium Dichromate‚ and Methylene Blue.1 Arantxa Alex Carpio Group 1 Sec. X – 4L March 24‚ 2015 ABSTRACT The effect of molecular weight and time on the rate of diffusion was determined using the agar-water gel test. A petri dish of agar-water gel with three wells was prepared and a prepared solution of each substance was dropped on each well; one with potassium permanganate (KMnO4)‚
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The Osmosis Scientific Paper Emily N. Charbonneau Grand Valley State University The point of this experiment was to observe if the different concentrations of sucrose would change the speed of osmosis. Osmosis is a process of a fluid that will pass through a semipermeable membrane into a solution which most of the time has a higher concentration. Osmosis will be demonstrated throughout the lab. The importance of osmosis in a plant and animal cell there is a cell membrane‚ which helps liquids and
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Diffusion is one of several transport phenomena that occur in nature. A distinguishing feature of diffusion is that it results in mixing or mass transport without requiring bulk motion. Thus‚ diffusion should not be confused with convection or advection‚ which are other transport mechanisms that use bulk motion to move particles from one place to another. In Latin‚ "diffundere" means "to spread out". There are two ways to introduce the notion of diffusion: either a phenomenological approach starting
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