Human Phys 1.3 Flashcards
What is diffusion?
Random molecular movement (move on their own)
How does diffusion always occur?
Down a concentration gradient (downhill)
What is simple diffusion determined by?
Amount of substance available
Velocity of motion
Number of size and openings (permeability)
What does facilitated diffusion always require?
Carrier protein
What is always true about flow down gradients?
There will always be an energy gradient (supports flow) and a resistance to flow
Flow
Movement of substances from one point in the system to another
Why does flow occur?
Due to the presence of an energy gradient
What can determine the direction of flow?
More than one gradient
What will there always be when it comes to flow?
Some form of resistance
What is true about resistance in flow?
It can be varied or physiologically controlled
Are there multiple gradients during flow?
Yes (working at same time)
What is osmosis?
Flow down gradient
How do molecules diffuse?
Independently of one another
Does the presence of a gradient mean flow will always occur?
No (due to resistance)
Chemical gradient
Flow occurs from higher to lower concentration