Exam 3 content Flashcards
(89 cards)
What are Cell membranes made up of?
It is made up of a phospholipid bilayer with carbs (for labeling), cholesterol to keep it fluid, and proteins (which can carry out common functions like transport).
What kinds of molecules can passively diffuse through a cell membrane?
Hydrophobic molecules like steroids can dissolve to pass through. Along with small uncharged molecules like O2 and C2.
What distinguishes active transport from passive transport?
Active transport requires ATP to occur
What are the characteristics of passive transport?
It requires no energy, and it moves molecules down a concentration gradient
Does the concertation gradient of diffusion move up or down?
Down
What occurs when dynamic equilibrium is established in diffusion?
There is still movement but not any net movement
Do two solutes in diffusion have any impact on each other?
No they move at thier own rate they are unaffected by eachother
What are some factors that influence the rate of diffusion?
Temperature, size of the molecule, polarity, and difference in the concentration gradient
What is osmosis?
The passive diffusion of water
What is “free water” in the context of osmosis?
“Free water” refers to water that is not connected to any of the other molecules in the solution
What does tonicity mean?
It refers to the ability of the cell to gain or lose water based on its own and the surrounding concentration levels.
What does is mean when a solution is hypertonic?
It means that the concertation of the solute it higher outside of the cell membrane.
What does it mean when a solution is hypotonic?
It means that concentration of the solution is higher inside the cell than outside the cell.
What does it mean when a solution is isotonic to the cell it surrounds?
It means that the concentration of the solute is equal inside and outside the cell
What happens to a human RBC when it’s in a hypertonic solution?
it to shrink/shrivel up (since it wants to reduce the concentration levels outside of it)
What happens to a human RBC when it’s in a hypotonic solution?
the cell is going to swell and burst due to the water coming in trying to dilute it
What happens to a human RBC when it’s in a isotonic solution?
It’s in an ideal solution and will be able to maintain a state of equilibrium
What do carrier proteins do?
They bind to molecules and modify their shape to help them get across the membrane
What does aquaporin do to help H2O diffuse across the membrane?
They support the diffusion of H2O by working with the gradient
What does it mean for an ion channel to ligand gated?
It means that in order for the channel to open a certain hormone or neurotransmitter needs to bind to the receptor for it to open
What does it mean for an ion channel to be voltage gated?
It means that when the potentials change inside/outside of the cell to a certain point it will trigger for the channel to open ex sodium potassium pump
What does it mean for an ion channel to be a leak channel?
It means that the channel is always open hence its a little leaky
What does it mean for an ion channel to be mechanically gated?
It means that there has to be physical pressure on the membrane for it to open
Is facilitated diffusion active or passive transport?
It is passive transport because it moves the ions down its concentration gradient and does not need ATP