Transport Across Membranes: Facilitated diffusion + Simple diffusion Flashcards
What are names for the two types of transport that exchange substances between cells and the environment?
The exchange of substances between cells and the environment occurs in ways that require metabolic energy (active transport) and ways that do not require metabolic energy (passive transport)
Are facilitated diffusion and simple diffusion examples of active or passive transport?
Facilitated and simple diffusion are both examples of passive transportation
What is the type of transportation that requires metabolic energy?
Active transportation
What are the two types of transportation and describe what they do/do not require?
There is active transportation that does require metabolic energy and there is passive transportation that does not require metabolic energy
What are the three factors to consider when talking about diffusion? (based on particles)
1) All particles are constantly in motion due to the kinetic energy they possess
2) The motion of particles is random, there is no set pattern to the way particles may move
3) Particles constantly bounce off of each other, including other objects
What does the term ‘passive’ refer to when describing passive transport?
‘Passive’ means the energy comes from the natural, inbuilt motion of particles rather than from an external source, like ATP
What is simple diffusion?
Simple diffusion is the net movement of molecules/ions from a region where they are highly concentrated to a region with lower concentration until they are evenly distributed
What type of state does simple diffusion occur in - liquids, solids or gases?
Simple diffusion occurs in gases or liquids, like oxygen and carbon dioxide
What two types of protein molecules are involved in facilitated diffusion?
Protein channels and Carrier proteins
What is facilitated diffusion?
A passive process that occurs down a concentration gradient at specific points on the plasma membrane, moving molecules from a region of high concentration to a region of lower concentration
How is the movement of charged ions/polar molecules made easier within the plasma membrane?
The movement of these molecules is made easier by transmembrane channels and carriers that span the membrane
What do protein channels/carrier proteins allow to pass through them?
Protein channels allow specific water - soluble ions to pass through, each channel opening up in the presence of different specific ions
How do protein channels perform facilitated diffusion?
Ions will bind with a protein channel causing it to change shape in a way that closes one side of the membrane and opens the other side
How do carrier proteins perform facilitated diffusion?
When molecules specific to the protein are present, they bind with the protein which causes a change in shape so the molecule is released to the inside of the membrane
Is there any external energy used in facilitated diffusion, like ATP?
No external energy is needed
