A&P Seeley 3.2

The movement of one specific ion or molecule across the membrane.

The movement of two different ions or molecules in the same direction across the plasma membrane

The movement of two different ions or molecules in opposite directions across the plasma membrane

Transport proteins that move specific ions and molecules from one side of the plasma membrane to the other

Proteins or glycoproteins in the plasma membrane with an exposed receptor site on the outer cell surface.

Acts as an intermediate between a receptor and other cellular proteins

Alpha, beta, and gamma

Membrane proteins that can catalyze chemical reactions on either the inner or the outer surface of the plasma membrane

The plasma membrane allows only certain substances to pass through it

• Directly through the phospholipid membrane
• Membrane channels
• Transport proteins
• Vesicles

The movement of solutes from an area of higher solute concentration to an area of lower solute concentration

The concentration difference between two points divided by the distance between the two points

The diffusion of water across a selectively permeable membrane.

Water channel proteins that increase membrane permeability to water in some cell types

The force required to prevent the movement of water by osmosis across a selectively permeable membrane

Solutions with the same concentration of solute particles that have the same osmotic pressure

A solution that has a greater concentration of solute particle and therefore a greater osmotic pressure

A dilute solution with the lower osmotic pressure

When water moves by osmosis from the cell into the hypertonic solution causing the cell to shrink

When a partition containing small holes is placed in a stream of moving liquid.

The process by which transport proteins mediate the movement of large water-soluble molecules

Each transport protein binds to and transports only a single type of molecule or ion

The result of similar molecules binding to the transport protein

The rate of movement of molecules across the membrane is limited by the number of available transport proteins

A carrier-mediated or channel-mediated process that moves substances into or out of cells from a higher to a lower concentration

A mediated transport process that requires energy provided by ATP

Involves the active transport of an ion out of a cell

The internalization of substances

A membrane-bound sac found within the cytoplasm of a cell

• (cell eating)
• Applies to endocytosis when solid particles are ingested and phagocytic vesicles are formed

• (cell drinking)
• Smaller vesicles are formed and molecules dissolve in liquid

The plasma membrane contains specific receptor molecules that recognize certain substances and allow them to be transported into the cell by phagocytosis or pinocytosis.

The membrane of the vesicle fuses with the plasma membrane and the content of the vesicle is expelled from the cell