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04. Cell Transport
Cell Transport
Term | Definition |
---|---|
Phospholipid bilayer | Forms a boundary between the cell and it's external environment. Made of two layers of lipids with the hydrophobic tails towards the inside. |
Homeostasis | Maintenance of constant internal conditions in an organism. |
Permeable | Allows materials to cross the cell membrane. |
Semipermeable | Allows some, but not all, materials to cross the cell membrane. |
Protein | Structures that are embedded in the cell membrane. Can be used as pores or pumps to let molecules into and out of the cell. |
Active transport | Drives molecules across a membrane from a region of lower concentration to a region of higher concentration. |
Against concentration gradient | The way molecules move during active transport. |
Endocytosis | The process of taking liquids or fairly large molecules into the cell by engulfing them in a membrane. |
Exocytosis | The release of substances out of a cell by the fusion of a vesicle with the membrane. |
Energy | ATP. Needed for active transport. |
Pump | Used during active transport to allow molecules against a concentration gradient. |
Passive transport | The movement of molecules across a cell membrane without energy input from the cell. |
Diffusion | The movement of molecules in a fluid or gas from a region of high concentration to a region of lower concentration. |
Osmosis | The movement of water from lower concentration of solutes to an area of higher concentration solutes through a membrane. |
Isotonic | The solution has an equal concentration of dissolved particles as the cell. Water moves across the membrane at the same rate. |
Hypertonic | Solution has a higher concentration of dissolved particles as the cell so the water flows out of the cell. |
Hypotonic | Solution has a lower concentration of dissolved particles as the cell so the water flows into the cell. |
Facilitated diffusion | Diffusion of molecules across a membrane through transport proteins. |
With Concentration Gradient | The way molecules move during passive transport. |
High to low | The way molecules move during passive transport. |
Solute | A substance that dissolves into a solvent. |
Solvent | The substance that is present in the greater amount that dissolves another substance. |
Equilibrium | The condition of a system in which competing influences are balanced, resulting in no net change |
Homeostasis | The maintenance of constant internal conditions in an organism. |