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49 Cards in this Set
- Front
- Back
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How does proteins move in lipids?
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They "float" freely
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Where can phospholipids move in all directions?
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The Bilayer
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When does the phospholipids stop moving?
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They never stop
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How many times does phospholipids move lateral?
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10^7 times per second
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How many times does phospholipids flip-flop?
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Once per month
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How is the fluid of the membrane impacted by?
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Levels of saturation of the fatty acid tails and the temperature.
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What's the difference between fluid hydrocarbon and viscous hydrocarbon?
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Fluid hydrocarbon is unsaturated and is spread apart. Viscous hydrocarbon is saturated and has a high grip with high and low temps.
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What can help keep membranes fluid by "breaking up" the lipids, particularly at low temperature?
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Steroid Cholesterol
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What can be made from your body that is essential?
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Cholesterol
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Where is the higher and lower cholesterol stored?
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Higher cholesterol is stored in cold areas and the lower cholesterol is stored in hotter areas.
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What is embedded in the fulid matrix of the lipid bilayer?
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A membrane is a collage of different ENZYMES
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The proteins in the membrane can be...
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Peripheral: anchored and move with the phospholipid in one layer.
Intergral: go from one side to the other and must have region of the protein containing hydrophobic amino acids |
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What are the various functions of the membrane proteins?
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Transporters, enzymes, cell surface receptors, cell surface identity markers, cell-to-cell adhesion proteins, and attachments to the cytoskeleton.
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What does transport do in the membrane?
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Transport of materials in and out of the cell.
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What does enzymes do in the membrane?
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Enzymes to facilitate chemical reactions
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What does cell surface receptor do in the membrane?
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The cell surface receptor transmits messages from outside the cell
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What does cell surface identity do in the membrane?
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It is a marker to let other cells (such as white blood cells), the cell type, or that the cell is "self".
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What two attachments are used to support the cell and/or the surrounding tissue?
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cell-to-cell and cell-to-cytoskeleton
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Membrane proteins and lipids are synthesized in what?
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In the ER and the Golgi
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Membrane proteins and lipids are transported where?
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Out in vesicles
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Membranes are bifacial, why?
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Proteins have to be oriented correctly to function and sugar groups can be attached on the outside.
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What are four ways to use diffusion?
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Liquids, solutes, gasses, anything concentrated in a space.
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What is diffusion?
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It is the movement of molecules from HIGH to LOW concentration.
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What are a few examples of Apolar molecules?
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Oxygen, Carbon dioxide, and hydrocarbons.
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What is an example of a small uncharged polar molecules?
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Water
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What is osmosis?
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The passive transport of water across a membrane.
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Water will always travel to where there is what?
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More solutes and less water.
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What is hypertonic?
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It has more solutes and less water
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What is hypotonic?
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It has less solutes and more water
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What is isotonic?
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It is equal between solutes and water
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What makes an animal happy?
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Isotonic
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What makes a plant happy?
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Hypotonic
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What kills both plant and animals?
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Hypertonic
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For a molecule to cross the membrane, it has to either:
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Directly cross through the lipids or cross through a protein.
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What about passive transport?
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There is no energy required, it moves from high to low concentration and molecules diffuse independantly of each other.
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What about active transport?
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It must have protein, requires energy (ATP), and can go against the concentration gradient (low to high).
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What is Endocytosis?
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endo = inside, cyt = cell.
Movement of substance into the cell. |
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What is phagocytosis?
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The cell takes in particulate matter.
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What is pinocytosis?
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The cell takes in only fluid.
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What is receptor-mediated endocytosis?
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Specific molecules are taken in after they bind to a receptor.
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What is exocytosis?
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Movement of materials out of the cell.
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What functions do the membranes do?
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Separate compartments and control molecular traffic in and out.
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What about selectively permeable membranes?
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Some substances can cross easily and others can not get across.
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What are membranes composed of mainly?
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Phospholipids
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Membranes automatically form into what with fatty acids ends attracted to each other?
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Bilayer
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What other componets are there of membranes include?
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Proteins, cell surgace makers, and phospholipids.
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Hydro____ heads, Hydro____ tails
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HydroPHILIC heads and hydroPHOBIC tails.
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Membranes are approximately what?
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50% phospholipids
50% proteins - variety (proteins act like bouncers; they say what gets in, out, and what is not allowed). |
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The membrane is "____"?
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Fluid
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