Passive Transport Flashcards
(20 cards)
What is passive transport
Movement of materials or molecules across the membranes without the use of the cells energy. Molecules use their own kinetic energy (energy of motion). Materials move DOWN their concentration gradient from high concentration to low concentration
What are some types of passive transport
Diffusion, Osmosis, and Facilitated Diffusion
What is diffusion
Movement of small uncharged molecules across a membrane. Example: oxygen and carbon dioxide
What is osmosis
Simply the diffusion of water
What does hypertonic mean
Refers to a solution having a higher concentration of solute in it than the solution it is being compared to
What does hypotonic mean
Refers to a solution having a lower concentration of solute in it than the solution it is being compared to
What does isotonic mean
Solutions have equal concentrations of solutes when compared
What is a solute
The substance that gets dissolved
What is a solvent
The substance that does the dissolving
Solute + Solvent + ?
Solution
What does permeable mean
Means it will pass through
How do animal cells respond to hypotonic solutions
water enters, cell swells and may burst (lysis)
How do animal cells respond to isotonic solutions
no NET movement of water, cell stays normal size
How do animal cells respond to hypertonic solutions
water leaves, cell shrinks and crenates
How do plant cells respond to hypotonic solutions
water enters, cell swells a bit and becomes turgid
How do plant cells respond to isotonic solutions
no net movement of water, cell stays normal size
How do plant cells respond to hypertonic solutions
water leaves, cytoplasm shrinks and plasmolyses
What is facilitated diffusion
The diffusion of molecules across the cell membrane with the aid of special carrier proteins or channel proteins
What are carrier proteins
Change shape to allow materials into a cell. They help speed up the rate of diffusion when the demand for molecules, such as glucose is high within a cell
What are channel proteins
Water filled passages that help charged particles called ions enter a cell
