Amoeba Sisters: Cell Transport

Cell membrane

Structure that regulates what goes in and out of cells

Phospholipid bilayer

Two layers of lipids with polar heads and nonpolar tails

Simple diffusion

Passive transport of small non-polar molecules across the cell membrane

Passive transport

Movement of molecules across the cell membrane without requiring energy

Facilitated diffusion

Passive transport of molecules with the help of transport proteins

Transport proteins

Proteins in the cell membrane that assist in the movement of molecules

Active transport

Movement of molecules against the concentration gradient, requiring energy (ATP)

ATP

Adenosine triphosphate, a molecule that provides energy for cellular processes

Sodium-potassium pump

Example of active transport that moves sodium and potassium ions across the cell membrane

Endocytosis

Process of bringing substances into the cell by fusing the cell membrane

Vesicles

Membrane-bound sacs formed during endocytosis to transport substances inside the cell

Receptor-mediated endocytosis

Type of endocytosis where substances must bind to receptors to enter the cell

Pinocytosis

Type of endocytosis that allows the cell to take in fluids

Exocytosis

Process of releasing molecules from the cell by fusing vesicles with the cell membrane

Cell wall

Structure found in plant cells that provides support and protection