Semmelweis
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| 282784114 | What is each cell covered by? | An extremely thin membrane | |
| 282784115 | What does the membrane do? | Seperates and protect the interior of the cell from its environment | |
| 282784116 | What is it also called? | Plasma membrane | |
| 282784117 | What is the second function of the membrane? | Interaction and communication with the cells environment | |
| 282784118 | What are RBC's called? | Erythrocytes | |
| 282784119 | In what microscope can the plasma membrane be seen? | Electron microcope | |
| 282784120 | How thick is the membrane? | 8-10 nm | |
| 282784121 | Where is the membrane also present? | In the cell interior (er, golgi-apparatus, lysosome, mitochondria) | |
| 282784122 | What layer does the membrane consist of? | The lipid bilayer | |
| 282784123 | What are the molecular compenents of this? | Lipids, proteins and a small amount of carbohydrates | |
| 282784124 | What are lipids? | Fal-like molecules | |
| 282784125 | What are the two parts of a lipid? | A hydrophobic (water repellant) and hydrophilic (water attractant) part | |
| 282784126 | What substances are they represented by? | Phospholipids, cholesterol etc. | |
| 282784127 | What is a micelle? | A circular arrangement of lipids, hydrophobic interior, hydrophilic exterior | |
| 282784128 | What is the physical properties of the interior of the membrane? | It is always hydrophobic | |
| 282784129 | What does this create? | A diffusion barrier | |
| 282784130 | What does the diffusion barrier repel? | Hydrophilic molecules and ions | |
| 282784131 | What does it allow through? | Hydrophobic molecules (o2 co2 steroids) | |
| 282784132 | How does the bilayer behave? | As a two dimensional fluid | |
| 282784133 | Is the bilayer motile? | Yes | |
| 282784134 | What does the fluidity depend on? | Amount of cholesterol, unsaturated fatty acids, temperature | |
| 282784135 | What does the bilayer form in an aqueous environment? | Circular vescicles | |
| 282784136 | How many percent of the membrane mass is proteins? | 25-75 % | |
| 282784137 | How many lipid molecules are there per protein? | 50 | |
| 282784138 | Two types of membrane proteins | Integral and peripheral | |
| 282784139 | How are the integral proteins bound? | Firmly and cannot be removed without destroying the bilayer | |
| 282784140 | How are transmembrane proteins shaped? | They extend across the bilayer in a "single-pass and multipass" function. Most important | |
| 282784141 | Membrane proteins partially embedded into the bilayer | Similar to TMP, but do not span the bilary | |
| 282784142 | Anchored membrane proteins | Located on one side, covalently bound lipid chain. | |
| 282784143 | Peripheral membrane proteins | Hydrophilic proteins on either extracellular or cytosolic surface. | |
| 282784144 | How are they attatched? | By weak bonds to an IMP | |
| 282784145 | Can they be removed? | Yes, without destruction | |
| 282784146 | What is Glycocalyx? | A Short sugar chain, covalently bound to proteins or lipids | |
| 282784147 | How is the membrane supported? | By the membrane skeleton | |
| 282784148 | What does it contain? | A network of filamentous proteins | |
| 282784149 | Lateral diffusion: | Proteins are motile and move in alteral direction | |
| 282784150 | Caveolae | Lipid rafts with caveolin on the inner side of the membrane | |
| 282784151 | Diffusion barrier | Inhibits free difusion of substances | |
| 282784152 | What goes through the barrier? | Small hydrophobic molecules (small fat) Small uncharged polar molecules (small ice) | |
| 282784153 | What doesn't go through the barrier? | Large uncharged polar molecules Ions | |
| 282784154 | Two mechanisms for uptake and release: | Membrane transport endocytosis and exocytosis | |
| 282784155 | how many of the proteins in cell are memebrane transport proteins? | 20-30 %! | |
| 282784156 | TWO GROUPS OF TRANSPORT PROTEINS? | Carrier proteins and channel proteins | |
| 282784157 | What does a carrier protein transport? | A molecule or ion | |
| 282784158 | How does it do this? | Conformational change | |
| 282784159 | What is facilitated diffusion? | Stuff is transported along their concerntration gradient (from high conc to low conc) no energy required | |
| 282784160 | What is active transport? | A pump, moving something against its concentration gradient, needs energy | |
| 282784161 | What re the two types of active transport? | Atp-pumps Secondary active transport | |
| 282784162 | What do ion channels form? | A hydrophilic channel across the membrane | |
| 282784163 | Water channel example: | Aquaporin | |
| 282784164 | Three types of contact between cell and environment: | Signal registration cell-cell recognition stable binding between cells | |
| 282784165 | Signal registration: | Membrane receptors | |
| 282784166 | Cell cell recognition: | adhesion molecules | |
| 282784167 | stable binding between cells: | intercellular junctional structures |
