AP bio ch5 and 6

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