Membrane Transport 2.6 Flashcards
What is passive transport?
The net movement of molecules from a high to low concentration without metabolic energy (ATP)
Identify two examples of passive transport.
Diffusion-movement of molecules from high concentration to low concentration across a membrane (small nonpolar molec)
Facilitated Diffusion-mvmt molec high concen to low concen through transport proteins (small polar/hydrophobic ions)
What is active transport?
Requires direct input of energy (ATP) to move molecules against the concentration gradient.
Identify three examples of active transport.
a pump, exocytosis, or endocytosis
What is required for active transport?
ATP
What is a concentration gradient?
When a solute is more concentrated in one area than another
What causes a concentration gradient?
A membrane separates the two concentrations, only allowing certain molecules in or out of the cell.
What is endocytosis?
The cell forms vesicles using ATP to transport large molecules into the cell.
Describe the three types of endocytosis.
phagocytosis-cell takes in large particles
pinocytosis-cell takes in extracellular fluid containing dissolved substances
receptor mediated-receptor proteins are used to capture specific target molecules in vesicles
Identify an example of a material that would require endocytosis.
proteins or lipids or other large molecules
How are the food materials brought in by endocytosis digested?
Lysosomes attach to the vacuole and release the nutrients, carrying the waste to the plasma membrane for exocytosis to occur.
What is exocytosis?
Internal vesicles use ATP to fuse with the plasma membrane and secrete large macromolecules out of the cell.
Identify an example of a material that would require exocytosis.
signaling proteins, hormones, and waste.
