Chapter 5 -1 Flashcards
(18 cards)
What are the different types of transport?
Diffusion
Passive transport
Active transport
Bulk flow
Passive transport ______ energy
Active transport ______ energy
not require
require
What is diffusion?
the movement of molecules across the selectively permeable lipid bilayer
What does diffusion occur with?
small and nonpolar molecules
What is diffusion affected by?
size, temp, concentration steepness
What is Osmosis?
the diffusion of water across a membrane
water moves down its concentration gradient
What is osmosis based of?
Tonicity, which is the relative solute concentration of 2 fluids
Hypotoinc if…?
Hypertonic if…?
Isotonic if…?
fewer solutes
more solutes
same amount
Cell survival depends on?
controlling water balance
What is passive transport?
facilitated diffusion -diffusion via transport proteins
What are the different types of passive transport?
channel proteins or gates
What do channel proteins/gates do?
allow large /polar molecules and ions
and can be affected by charge - electrical gradient
What happens in active transport?
a solute is moved against its concentrations gradient
What does active transport require?
Energy, ATP and protein pumps
What does ATP activate?
transporter protein/pump
What does the binding of a phosphate group do?
changes protein shape and affinity for solute in some pumps
What is an example of ATP?
Sodium- Potassium pump
What does the membrane pump set up?
the membrane potential
