CELL STRUCTURE CELL THEORY: Structural and functional unit of all living things New cells arise from already existing cells Cells contain information that instructs growth. This information can be passed onto new cells. MICROSCOPES: There are two main types of microscopes: Light and Electron Electron Micrographs- shown in colour LIGHT ELECTRON Uses beam of light Magnification = x1500 Resolution = 200 nm Wide range of specimens can be used Samples are fairly quick + easy to prepare
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(Table 1) during the simulation period of 0.5 s (Fig 1A and 1B). The partial densities of the peptide distribution were broadened owing to the unfolded conformations (Fig 1A and 1B). Simulations for BMAP27 interaction with zwitterionic and anionic membranes depicted a differential peptide folding and kinetics. Results showed a fast peptide attraction (~ 50-80 ns) followed by slow binding and reorientation (~100-500 ns) on the bilayer surface. The calculated -helical conformation of BMAP27 revealed
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Substances will move through the membrane by diffusion. This is the random spreading out of particles until they are even. For example‚ when you put your instant coffee in boiling water‚ the coffee particles spread out and fill the entire mug‚ this is diffusion. A second way that substances can move through the cell membrane is by osmosis. This is a special type of diffusion where water moves from a high to a low concentration through a ’partially permeable membrane’‚ or a membrane specially shaped to only
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Cells must move materials through membranes and throughout cytoplasm in order to maintain homoeostasis. The movement is regulated because cellular membranes‚ including the plasma and organelle membranes‚ are selectively permeable[1]. The purpose of an automatic flow of molecules is to create equilibrium on each side of the membrane. In order for molecules to pass through the membranes‚ there must be pores. The size of the pore determines what molecules can cross. Due to the size and polarity‚ only
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Phospholipids receive and transmit signals across the cell membrane and act as a store room for energy. The main role of phospholipids is that they can form lipid bilayers. It is an amphipathic molecule. The head which is hydrophilic contains a group of phosphate‚ a diglyceride and a simple molecule e.g. choline. The tail is hydrophobic and is made up of fatty acids. Phospholipids receive and transmit signals across the cell membrane and act as a store room for energy. Fatty acids Fatty acids
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and organs. 5. Describe cellular metabolism‚ and discuss the components involved. 6. Explain cell membrane fluidity according to the fluid mosaic model. 7. Briefly describe the three phases of catabolism of proteins‚ lipids‚ and polysaccharides that are found in foods. 8. What effect do plasma proteins have on osmolality? 9. Identify the types of transport of water and solutes across cell membranes and the predominant intracellular and extracellular cations. 10. Describe the processes of mitosis
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OCR BIOLOGY UNIT F221 Blood tests 1. Put a band (tourniquet) around the arm to make the vein stand out 2. Clean the area around the vein with an alcohol based solution 3. Push a sterile needle‚ attached to a sterile syringe into the vein 4. Pull back the plunger of the syringe to suck the blood into the syringe 5. When the necessary volume of blood has been extracted‚ remove the syringe and needle‚ loosen the tourniquet and press a small ball of cotton wool over the
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nucleus Eukaryote = with a nucleus Eukaryotic Cells Cytoplasm (or Cytosol). This is the solution within the cell membrane. It contains enzymes for metabolic reactions together with sugars‚ salts‚ amino acids‚ nucleotides and everything else needed for the cell to function. Nucleus. This is the largest organelle. Surrounded by a nuclear envelope‚ which is a double membrane with nuclear pores - large holes containing proteins that control the exit of substances such as RNA from the nucleus.
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INTRODUCTION: Osmosis is defined as the net movement of water or any other solutions molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a partially permeable membrane such as a cell wall‚ which lets smaller molecules such as water through but does not allow bigger molecules to pass through. The molecules will continue to diffuse until the area in which the molecules are found reaches a state of equilibrium‚ meaning
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2.3. Membranes and modules for forward osmosis: 2.3.1. FO Membranes Generally‚ any dense‚ non-porous‚ selectively permeable material can be used as a membrane for FO. Such membranes have been tested (in flat sheet and capillary configurations) in the past for various applications of FO. In early studies‚ the researchers applied various FO membrane materials‚ including bladders of pigs‚ cattle‚ and fish; collodion (nitrocellulose); rubber; porcelain; and goldbeaters’ skin [36]. By 1960‚ Loeb and
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