Vocabulary for Unit 7 Flashcards
Amphipathic
Containing hydrophilic and hydrophobic elements.
Integral membrane protein
Any membrane protein that spans the entire lipid bilayer. Also called transmembrane protein.
Peripheral membrane protein
Any membrane protein that does not span the entire lipid bilayer and associates with only one side of the bilayer.
Lipid anchored protein
A covalently attached fatty acid serves to anchor the protein to either face of the cell membrane.
Transmembrane
To span the entire lipid bilayer
Glycoprotein
Any protein with one of more covalently bonded carbohydrate groups.
Detergent
A type of small amphipathic molecule used to solubilize hydrophobic molecules in aqueous solution.
Membrane permeability
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
Diffusion
Spontaneous movement of a substance from a region of high concentration to one of low concentration (i.e., down a concentration gradient)
Osmosis
Diffusion of water across a selectively permeable membrane from a region of high water concentration (low solute concentration) to a region of low water concentration (high solute concentration).
Passive diffusion
The diffusion of a substance across a plasma membrane or organelle membrane.
Active transport
The movement of ions or molecules across a plasma membrane or organelle membrane against an electrochemical gradient. Requires energy (e.g. from hydrolysis of ATP) and assistance of a transport protein (e.g., pump).
Pump
Any membrane protein that can hydrolyze ATP to power active transport of a specific ion or small molecule across a plasma membrane against its electrochemical gradient.
Na+/K+ pump
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Na+/K+ pump
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Symport
a mechanism of transporting two compounds simultaneously across a cell membrane in the same direction, one compound being transported down a concentration gradient, the other against a gradient.
Antiport
a mechanism of coupling the transport of two compounds across a membrane in opposite directions.
