Chapter 7 Vocab Flashcards
Active transport
A energy-required movement of substance across a biological membrane against a gradient
Amphipathic
Possessing both hydrophilic and hydrophobic properties
Aquaporin
Protein channel that increases the diffusion rate of water through the plasma membrane
Carrier protein
Protein in the plasma membrane that facilitates the diffusion of a specific lipid insoluble molecule
Cell wall
A structure in plants and bacteria that gives rigidity to the cell
Channel protein
Provides a channel through the plasma membrane for small polar molecules and ions
Concentration gradient
The gradual difference in the concentration of solutes as a function of distance through the solution
Diffusion
The passive movement of molecules from high to low concentration
Endocytosis
Active transport where molecules are engulfed by the plasma membrane and form a phagosome or food vacuole within the cell
Exocytosis
Active transport process by which membrane bound secretory vesicles fuse with the plasma membrane and release the vesicle contents into the external environment
Facilitated diffusion
A type of passive transport, facilitated by transport proteins
Fluid mosaic model
The model for membrane structure which proposes a double phospholipid bilayer in which proteins and cholesterol are embedded
Glycolipids
Lipids with attached carbohydrates which serve as markers for cellular recognition
Glycoproteins
Membrane bound proteins with attached carbs involved in cell to cell interactions
Hypertonic
A solution with higher solute concentration relative to another solution
Hypotonic
A solution with lower solute concentration relative to another solution
Ion pump
A transmembrane protein that moves ions across a plasma membrane against their concentration gradient
Isotonic
Solutions of equal solute concentration
Osmosis
Passive movement of water molecules across selectively permeable membrane down a concentration gradient
Passive transport
The movement of substances across a biological membrane without energy use
Phagocytosis
A specific form of endocytosis that involves the engulfment of solid particles by the plasma membrane
Pinocytosis
The uptake of liquids or fine suspensions by endocytosis
Plasma membrane
A selectively permeable phospholipid bilayer forming the boundary of all cells
Plasmolysis
The process in plant cells where the plasma membrane pulls away from the cell wall as a result of the loss of water through osmosis
Selectively permeable
A membrane that acts selectively to allow certain substances to pass
Surface area:volume ratio
The relationship determines capacity for effective diffusion in a cell
Transmembrane protein
Protein that spans the plasma membrane
Turgor
The force exerted outward on a plant cell wall by the water contained in the cell
