college biology-chapter 5

transport proteins

allow materials to pass through the cell membrane using the interior of the protein; may or may not require energy

integral proteins

the general name for proteins that are physically embedded within the cell membrane

recognition proteins

act as molecular fingerprints to identify tissues or individuals

peripheral proteins

a general group of proteins positioned at the surface of the membrane

receptor proteins

bind extracellular substances that trigger changes in the cell's activity

passive transporters

proteins that allow molecules to move through the plasma membrane without expending energy

ion selective channels

contain molecular gates that move small molecules

bulk flow

mass movement of one or more substances in response to pressure, gravity, or other external force

hydrostatic pressure

the general term for a fluid force exerted against a cell wall and/or membrane enclosing the fluid

turgor pressure

term for hydrostatic pressure in plants

Exocytosis

a cytoplasmic vesicle moves to the cell surface; its own membrane fuses with the plasma membrane while its contents are released to the environment

receptor-mediated endocytosis

chemical recognition and binding of specific substances; coated pits sink into the cytoplasm and close on themselves

membrane cycling

membrane initially used for endocytotic vesicles returns receptor proteins and lipids back to the plasma membrane

Endocytosis

small patch of plasma membrane balloons inward and pinches off inside the cytoplasm

Pinocytosis

"cell drinking" / taking in liquid particles

fluid mosaic model

a composition of phospholipids, proteins, sterols, and gycolipids

phosopholipid

the primary component of the cell membrane; consists of both hydrophilic and hydrophobic regions

adhesion proteins

help cells of the same type stick together

communication proteins

Let signals travel rapidly between two adjoining cells

lipid bilayer

the double layer of phospholipids that forms the cell membrane

ATPases

use the energy of adenosine triphosphate to actively transport molecules across the membrane

osmosis

diffusion of water across a selectively permeable membrane (water concentration gradient between two regions)

Tonicity

refers to the relative solute concentrations of the fluids

hypotonic solution

the fluid one one side of a membrane that contains fewer solutes than the fluid on the other side of the membrane

hypertonic solution

the fluid on one side of a membrane that contains more solutes than the fluid on the other side of the membrane

isotonic solution

have the same solute concentration

osmotic pressure

the amount of force that prevents further increase in a solution's volume

Phagocytosis

"cell eating"...taking in solid particles / a cell engulfs microorganisms, large edible particles, and cellular debris