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33 Cards in this Set
- Front
- Back
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Cellular Membrane
What is Amphipathic ? |
Molecule with both a hydrophilic region and a hydrophobic region
Ex: phospholipid in membrane bi layer |
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Cellular Membrane
What is a Fluid Mosaic Model? |
Membrane is a fluid structure with various proteins embedded in it or attached to the phospholipid bi layer
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Cellular Membrane
What is Cholesterol? |
Located between phospholipid molecules, act as a temperature buffer by also interfering with phospholipids preventing them from packing in close together.
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Membrane Proteins
What are Integral Proteins? |
Transmembrane protein with hydrophobic regions that extends through the hydrophobic interior membrane; with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane.
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Membrane Proteins
What are Peripheral Proteins? |
Protein loosely bound to the surface of a membrane or to part of an integral protein; not embedded in the lipid bilayer.
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Membrane Protein
What are Carbohydrates? |
Responsible for cell-cell recognition, which results in:
a) Embryonic organization of cells into tissues, organs. b) Rejection of foreign cells by the immune system. c) Make cells unique (markers). |
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Membrane Protein
What are Glycolipid? |
Lipid with one or more covalently attached carbohydrates.
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Membrane Proteins
What are Gylcoprotiens? |
Protein with one or more covalently attached carbohydrates
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Membrane Structure
What is Selective Permeability? |
Property of biological membranes that allows them to regulate the passage of substances across them.
Example: Muscle cell. a) Sugars, amino acids, other nutrients; oxygen – IN b) Metabolic wastes; carbon dioxide – OUT |
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Membrane Structure
What are Transport Proteins? |
Transmembrane protein that helps a certain substance or closely re-lated substances to cross the membrane.
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Membrane Structure
What are Channel Proteins? |
Proteins that form a hydrophilic channel that allows certain molecules to pass thru the membrane
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Membrane Structure
What is Aquaporin? |
Channel protein that specifically facilitates the diffusion of free water across the membrane (osmosis). a) Allows the single-file passage of 3,000,000,000 water molecules per second.
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Membrane Structure
What are Carrier Proteins? |
Proteins that taxi specific molecules across the membrane by changing shape. a) Glucose transporter in red blood cells shuttles glucose across the membrane 50,000 times faster than if glucose were to diffuse on its own.
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Passive Transport
What is Diffusion? |
Movement of molecules from areas of higher concentration to areas of lower concentration.
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Passive Transport
What is Concentration Gradient? |
Region along which the density of molecules increases or decreases
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Passive Transport
What are Passive Transport? |
Diffusion of a substance across a biological membrane.
1. No energy expended by the cell for it to occur. 2. Concentration = potential energy, drives diffusion. |
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Passive Transport
What is Osmosis? |
Diffusion of water across a selectively permeable membrane. Movement of water across cell membranes and the balance of water between a cell and its environment are crucial to the survival of living organisms.
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Passive Transport
Osmosis What is Tonicity? |
Ability of a surrounding solution to cause a cell to gain or lose water
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Passive Transport
Osmosis What is Isotonic? |
Surrounding solution causes no net movement of water into or out of the cell
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Passive Transport
Osmosis What is Hypertonic? |
Surrounding solution causes the cell to lose water; contains more dissolved solutes.
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Passive Transport
Osmosis What is Hypotonic? |
Surrounding solution causes the cell to gain water; contains less dissolved solutes
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Passive Transport
Osmosis What is Osmoregulation? |
Regulation of solute concentrations and water balance by a cell or organism.
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Passive Transport
Osmosis What is Turgid? |
Swollen or distended, as in plant cells; plant cell is generally hypertonic to its environment.
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Passive Transport
Osmosis What is Flaccid? |
Limp, lacking turgor, as in plant cells; plant cell is generally isotonic to its environment.
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Passive Transport
Osmosis What is Plasmolysis? |
Phenomenon in plant cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; plant cell is very hypotonic to its environment.
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What is Facilitated Diffusion:
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Passage of molecules down a concentration gradient and across a biological membrane with the assistance of specific trans-membrane transport proteins (requires no energy).
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What is a Active Transport?
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Movement of a substance across a cell membrane
against its concentration; mediated by specific transport proteins (requires energy - ATP). Reset button for nervous system. |
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Active Transport
What is a Sodium Potassium Pump? |
Transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell (requires energy – ATP).
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Active Transport
What are Proton Pumps? |
Transport protein in the plasma membrane of plant, fungi, and bacteria cells that actively transports hydrogen out of the cell against the concentration gradient (requires energy – ATP).
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Active Transport
What are Cotransport? |
Coupling of “downhill” diffusion of one substance to “uphill” transport of another substance against its own concentration gradient.
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Bulky Transport
What is Exocytosis? |
Cellular secretions (exit) of biological molecules by the fusion of vesicles containing them with the plasma membrane
Examples: Insulin from pancreatic cells; neurotransmitter from neurons. |
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Bulky Transport
Exocytosis What is Phagocytosis? |
Large particulate substances or small organisms are taken up by the cell; carried out by some protists and animal immune cells (requires much energy).
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Bulky Transport
Exocytosis What is Pinocytosis? |
Extracellular fluid and its dissolved solutes are ingested by the cell; (requires much energy).
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