Chapter 4- Passive and Active transport rundown

What is selective permeability

a trait of cell membranes, allowing the passage of some molecules but not others

Passive transport requires how much energy?

None

What is diffusion

the process of the random movement of particles towards a desired state of equilibrium

What is the usual direction of diffusion

High concentration to low concentration

Diffusion of molecules across a membrane depends on what

diameter, temperature, concentration gradients, and area

What kind of molecule diameter diffuses the easiest ?

Small

What kind of temperature allows for prime diffusion

Higher temperatures

What kind of concentration gradients result in prime diffusion

Higher concentration gradients

What kind of surface areas result in prime diffusions?

Larger surface areas

Passive transport is also known as what?

Simple diffusion

What molecules can be diffused simply (through passive transport)

Non polar, hydrophobic, small, uncharged molecules

What are aquaporins

Channels specifically made for the diffusion of water

What is osmotic pressure?

The amount of pressure needed to prevent the flow of water

What is osmolarity?

the total number of solute particles per liter of water ( or how much of the solute has been dissolved by water)W

What is the connection between osmolarity and osmotic pressure

The higher the osmolarity, the higher the osmotic pressure

What is tonicity

The measure of the relative concentration of the solutes on either side of the membrane

What does tonicity determine

The direction of water movement

Isotonic solution means that

There are equal amounts of solution on both sides of the membrane

Hypotonic solution means that

There is a lower concetration of membrane impermeable solutes than the other solution

Hypertonic solution means

There is a higher concentration of membrane impermeable solutes than the other solution

What is the movement/ concentration gradient of water

Hypotonic to hypertonic (low to high)

What happens to cells in a hypotonic solution?

They take in water, and burst

What happens to cells in hypertonic solutions?

they loose water, and shrivel

What is turgor pressure

a kind a pressure that is built when cells with walls are attempting to limit their water intake

What kind of diffusion is used for the transport of polar molecules

facilitated diffusion

how are polar molecuels moved across a membrane?

Through channel and carrier protiens

What are channel protiens

Protions that form channels in the membrane

What are carrier protiens

protiens that bind to substances to speed up their diffusion

What is active transport

the kind of diffusion that requires ATP energy or something like it

What is primary active transport

using atp to move substances against their concentration gradients

What is one way to remember primary active transport

Same concentration to same concentration (High to high, or Low to Low)

What is secondary active transport

the kind of diffusion that uses left over energies from primary transport and/or an existing concentration gradient to move particles against their gradients

What is one way to remember the movement seen in secondary active transport?

Low to high concentrations.