Biology (Day 15; Passive and Active Transport) Flashcards
Understand the lesson
Passive transport
type of transport that does not require energy to occur
concentration gradient
a region of space over which the concentration of a substance changes
permeability
the quality of a membrane that allows substances to pass through it
equilibrium
the state at which a substance is equally distributed throughout a space
what is diffusion
during diffusion, substances move from an area of high concentration to low concentration, until the concentration becomes equal throughout a space
After reaching equilibrium, do particles stop moving across the cell membrane?
no; this is a continuous process
Why does diffusion only work with smaller, uncharged particles?
Only smaller particles can easily diffuse through the lipid bilayer, whereas large particles cannot fit in between the individual phospholipids that are packed together
Facilitated diffusion
larger molecules undergo facilitated diffusion through the usage of membrane proteins
What types of membrane proteins are there?
channel proteins and carrier proteins
Do molecules that undergo facilitated diffusion move within a concentration gradient?
yes; but the transport proteins protect them from the hydrophobic region as they pass through
Active transport
type of transport that requires energy to occur
what happens in active transport?
substances move against the concentration gradient (from areas of low concentration to high concentration)
Which protein does active transport require?
carrier proteins
True or false. Active transport requires both carrier proteins and channel proteins.
false; they only require carrier proteins
How do the carrier proteins in active transport differ from those in facilitated diffusion?
they need ATP to change conformation
