Transport

How things enter and leave a cell?

How many types of passive/active transport are there?

passive = 3

Active. = 3

List the types of passive transport?

Osmosis

Diffusion

Facilitated Diffusion

List the types of Active Transport:

Endocytosis

Exocytosis

Active Transport

Define Osmosis

The transport of water across a semi-permeable membrane (cell membrane)

It moves down the concentration gradient until an equilibrium is reached

If there is a higher concentration of solutes within the cell than outside, what happens to reach equilibrium?

Solutes cannot travel across the cell membrane (because it is too big), therefore the water will travel across the cell membrane, down the concentration gradient, into the cell (hypotonic)

The water is attracted to the solutes, so it will move across the cell membrane until an equilibrium is reached.

Isotonic solution definition:

ISO = same

same conc of water in cell and in solution

Hypotonic definition:

HYPO = Less

less solutes outside cell

Hypertonic solution:

HYPER = More

More solutes outside cell

What travels through Carrier Proteins? How does it work?

Large, Non-lipid-soluble molecules

Molds around specific molecules

Glucose and Amino Acids

What travels through Channel Proteins? How does it work?

Water filled channels, carries water soluble materials

Define Simple Diffusion:

The transport of lipid soluble molecules across the phospholipid bilayer

this could be oxygen, carbon dioxide, fats and vitamins

Define Osmosis:

The transport of water across a cell membrane, via phospholipids mainly, or channel proteins, down the concentration gradient.

Define facilitated diffusion:

The transport of non lipid soluble molecules across a cell membrane using a channel protein (if theyre small) or carrier protein (if theyre large, where the protein shape will change).

Define Active Transport:

The transport of molecules across a membrane with ATP (Adenosine Triphosphate)

It, like diffusion, requires protein carriers, what makes it different from diffusion, is it goes against the concentration gradient, therefore it uses ATP

Define Passive Transport:

The movement of molecules across a membrane that does not require ATP (Adenosine Triphosphate)

Define solute pumping:

Baso Active transport

moving against conc gradient with ATP, examples include sodium-potassium pump,

Define Exocytosis

The transport of hormones, mucus and waste, packaged by the Golgi Apparatus which then binds to the membrane and expels it out. (Involving ATP)

Define endocytosis:

It forms in the membrane then travels towards a lysosome where the contents within the vesicle are broken down.

It usually carries dead cells or bacteria.

The break down of this is called phagocytosis

Define phagocytosis:

The process of engulfing a large cell such as bacteria to remove it from the environment. (via endocytosis, taken to lysosome enzyme to break it down)

Define Pinocytosis:

“the cell drinking” droplets of dissolved fats from outside the cell.

The only way molecules will travel across the plasma membrane is if:

they are small enough

they are not polar

they are assisted by a membrane carrier

What travels passively across a membrane, explain why?

Oxygen,Carbon Dioxide, Glucose

They are being used and created all the time, they need to be transported consistently