Proton exchange membrane fuel cell

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    High temperature proton exchange membrane fuel cells (HT-PEMFCs) are a promising clean technology, especially for automobile applications.1 These devices generate electricity from the chemical reactions that occur in the anode side of the cell, using H2 as a fuel and generating heat and water as by-products.2, 3 However, experimental studies using HT-PEMFCs show that degradation of the cell can occur after certain hours of operation (around 500 hours).4 Some of the factors that contribute to the degradation of the HT-PEMFCs are rupture of the bulk polymer backbone of the membrane, H3PO4 loss and poisoning of the catalyst layer.5 These degradation problems must be overcome in order to commercialize this type of fuel cells.5 Consequently, extensive…

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    or without molecular oxygen3. Serratia Marcescens is a gram negative bacterium. Gram negative bacteria have a thin cell of a single layer of peptidoglycan that is enclosed by an outer membrane. The outer membrane is surrounded by special phospholipids composed of fatty acids called lipopolysaccharides that are attached to a glucosamine…

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    Organelles of Animal Cells The Nucleus: ~A large, round organelle visible under the microscope. Functions- Regulation • Controls the cell’s activities • Controls cell reproduction Contains genetic material - DNA that makes up the genes and chromosome. The Ribosome: ~Made of dozens of different proteins as well as RNA, also found in large numbers in the cytoplasm of living cells. Ribosome are typically composed of two subunits: • Large subunit • Small subunit “ Free” Ribosome makes…

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    Bacteriorhodopsin Experiment

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    Abstract Bacteriorhodopsin is located in the plasma membrane of Halobacterium halobium, where it acts as a proton-pump, transporting protons out of the cell. Since its discovery in 1979, much research has been done on Bacteriorhodopsin and there have been many advancements in our knowledge. Firstly, on its structure and function and secondly, on the conformational changes it undergoes during retinal isomerisation. Introduction Bacteriorhodopsin is a globular protein, (Henderson, 1975) which…

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    inside a cell, such as a normal pH, salinity, and ion concentration, to keep the cell healthy. There are several parts of the cell that play a role in homeostasis, but one of the more prominent ones is the phospholipid bilayer membrane. The cell membrane surrounds the cell, and therefore plays a large role in keeping the internal conditions of the cells constant. As mentioned earlier, the phospholipid bilayer cell membrane is crucial in keeping the internal conditions of the cell constant. This…

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    Osmosis In The Human Body

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    of 70% of water that in which is the main component of the cells within one’s bodies. Within these cells, there are particles that move inside and outside through a semi-permeable membrane. This process is called diffusion. In diffusion, particles move in motion at a random speed from a high concentration to an area of low concentration until all of the molecules are dispersed evenly. It is important to remember that involvement with diffusion depends on the concentration. The greater the…

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    Muscle Cells Lab Report

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    maintaining body position, and regulating body temperature. In a lab, the process of muscle contraction was investigated by exploring the sliding filament theory. An experiment was conducted to determine whether muscle length played a role in the amount of force a muscle produces. In order to fully understand how a muscle contracts, it is necessary to first understand the structure of muscle cells. Muscles cells are large cells that are surrounded by a special membrane called the sarcolemma and…

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    the outer and inner mitochondrial membrane.The outer membrane is porous and freely traversed by ions and small, uncharged molecules through pore-forming membrane proteins (porins), such as the voltage-dependent anion channel VDAC [19]. Any larger molecules, especially proteins, have to be imported by special translocases. Because of its porosity, there is no membrane potential across the outer membrane. By contrast, the inner membrane is a tight diffusion barrier to all ions and molecules. These…

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    A single cell cannot grow larger and larger indefinitely because on a cellular level and metabolic level, a cell requires essential provisions, cell-to-cell communication, and transport of molecules/nutrients. The outside of a cell grows slower than the inside of a cell. If a single cell were to continuously grow the outside layer of the cell would not be able to keep up. The larger a cell is, the more difficult it is to transport nutrients and oxygen from outside of the cell into the inside of…

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    Facilitated Diffusion

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    moving across a membrane from a high concentration area to a low concentration area without any forces acting upon the substance. Facilitated diffusion is a passive diffusion process involving the transportation of large or polar molecules and ions across the cell membrane (which they cannot normally pass through) with the help of transport proteins. Because facilitated diffusion is a form of passive transport, no energy is required for the movement of a solute from a high solute concentration…

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