Plasma membrane
A phospholipid bilayer with embedded proteins that surrounds both cells and organelles
Fluid Mosaic Model
model that explains the structure of cell membranes
Recognition protein:
Cell surface markers that identify cell types
Receptor proteins:
Proteins that recognize and bind to substances outside of the cell
Transport protein:
Protein that helps substances move across cell membrane
Enzyme:
Protein that assist chemical reactions inside cell
Peripheral proteins:
Proteins loosely attached to the surface of the membrane
Integral proteins
Proteins that penetrate hydrophobic core
Diffusion:
Process of random movement toward a state of equilibrium
Concentration
The amount of solute relative to the amount of solvent
Concentration gradient:
A difference in concentration of a substance across the space
Equilibrium:
Condition in which the concentration of a substance is equal throughout
Passive transport:
Movement of molecules across a cell membrane from an area of high concentration to an area of low concentration
Simple diffusion:
Random movement of molecules through the lipid bilayer of a membrane
Osmosis:
Special kind of diffusion that involves the movement of water through membrane
Hypertonic
An adjective describing a solution that has a higher solute concentration than another solution
Hypotonic:
An adjective describing a solution that has a lower solute concentration than another solution
Isotonic:
Adjective describing a solution that has an equal solute concentration as another solution
Facilitated Diffusion:
Proteins assisting in moving molecules across the membrane, down the gradient
Channel Proteins:
Proteins that go completely through the membrane and provide a safe passage through a polar core
Carrier Proteins:
Proteins which bind to the molecules to shield them from the interior of the membrane and change shape to transport them across the membrane
Active transport:
Transport of material across the cell membrane that goes up the concentration gradient
Sodium potassium pump:
A carrier protein that uses ATP to actively transport sodium ions (Na+) out of the cell and potassium ions (K+) into the cell
Bulk transport:
Moving large quantities of materials into or out of cell
Endocytosis:
Process by which material is brought into a cell by invagination of the plasma membrane and the formation of a vesicle
Exocytosis:
Process by which material is pushed out of a cell by invagination of the plasma membrane and the formation of a vesicle
Coupled Transport
The movement of more than one molecule at the same time across a cell membrane.
Symport
A mechanism of transport across a membrane in which two different molecules move in the same direction in a coupled transport
Uniport
A mechanism of transport across a membrane in which only one molecule at a time passes across the membrane.
Antiport
A mechanism of transport across a membrane in which two different molecules move in opposite directions in a coupled transport
Phagocytosis
"cell eating" type of endocytosis in which large particles are taken in by the cell
Pinocytosis
"cell drinking" type of endocytosis in which liquids or very small particles are taken in by cells
Receptor mediated endocytosis
Type of pinocytosis that is very specific and efficient in which specific molecules can be brought into the cell and are determined by receptors
Cell junctions
Special membranes, formed by cells, that allow cells to attach to one another, communicate with one another, and exchange materials with one another
Desmosome
A strong cell to cell junction that attaches adjacent cells to one another
Tight Junction:
Leak proof junction that creates tight seal between cells
Gap Junction:
Form channels between adjacent cells and allow communication between cells with the exchange of materials