| A | B |
|---|
| The process of keeping the internal conditions in an organism stable | Homeostasis |
| The movement of materials into and out of cells | Cellular transport |
| The membrane that surrounds the contents of a cell and allows only certain things into and out of the cell | Cell membrane |
| A property of cell membranes that allows only certain things to cross by not others | Selectively permeable |
| The two layers of phospholipid molecules arranged tail to tail that help to make up cell membranes | Phospholipid bilayer |
| Processes such as endocytosis and exocytosis that require some of the cell's energy to move from an area of lower concentration to an area of higher concentration | Active transport |
| Processes such as osmosis and diffusion that do not require energy from the cell | Passive transport |
| The movement of molecules from an area of higher concentration to an area of lower concentration | Diffusion |
| A different in the concentration of ions or other dissolved particles between two regions | Concentration gradient |
| The state of having equal concentrations | Equilibrium |
| The diffusion of molecules across a membrane through special proteins in the membrane | Facilitated diffusion |
| Proteins present in the cell membrane that allow different types of substances to pass through the membrane | Transport proteins |
| The movement of water across a membrane | Osmosis |
| Dissolved particles | Solute |
| Having a higher solute concentration outside the cell and causing the cell to shrink | Hypertonic |
| Having a higher solute concentration inside the cell and causing the cell to swell | Hypotonic |
| Having equal solute concentrations inside and outside the cell | Isotonic |
| A protein present in the cell membrane that helps to move materials into and out of the cell | Transport protein |
| Process used by a cell to take in a large particle | Endocytosis |
| Process used by a cell to release materials out of the cell | Exocytosis |
| the smallest unit of life | cell |
| a barrier that separates a cell from its surroundings; it controls what comes in and goes out of the cell | cell membrane |
| another term for cell membrane | Plasma membrane |
| a normal biological response in which the effects of a reaction slow or stop that reaction. Where the cell or body's response is opposite of the stimuli | negative feedback loop |
| a closed chain of cause and effect that amplifies a change or disturbance in a system, making it self-reinforcing. | positive feedback loop |
