cell transport

diffusion

The movement of molecules from an area of high concentration to an area of low concentration (hypertonic solution -> hypotonic solution)

osmosis

The movement of water across the cell membrane

(hypotonic -> hypertonic) 

osmotic pressure

The force exerted by the water within the animal cell (osmosis)

turgor pressure

The force exerted by the water within the plant cell against the cell wall

plasmolysis

cell membrane shrinking away from cell wall when placed in a hypertonic (high solute concentration) environment, → wilting

crenation

plasmolysis in red blood cells

hypertonic

High solute concentration solution (high solute; low water)

hypotonic

Low solute concentration solution (high water; low solute)

isotonic

Same solute concentration solution

phagocytosis

Cell eating, when the cell membrane engulfs solids/more extensive materials

pinocytosis

Cell drinking, when the cell membrane forms vesicles around liquids

receptor-mediated endocytosis

Receptors on the membrane have to bind to the substance for it to move into the cell. 

endocytosis

A type of transport where a cell takes in food/liquid

exocytosis

A type of transport where a cell pushes food/liquid out of the membrane. 

solute

being dissolved by solvent

solvent

dissolving solute

concentration

amount/percentage of something in a substance

facilitated diffusion

Transport proteins within the membrane help move molecules across the cell membrane (passive transport)

active transport

Transport that requires ATP energy 

passive transport

Transport that does not require ATP energy 

semi permeable

When the cell only allows some substances to pass through it but not others. 

equilibrium

When molecules are spread evenly throughout an area, an equilibrium is balance, and diffusion stops

contractile vacuole

Organelle within the cell that helps pump out excess water, preventing the cell from over-expanding.

• helps w osmosis in plants

homeostasis

Maintaining biological balance, stable

cell membrane

Made up of a phospholipid bilayer, it helps move things in and out of the cell. 

sodium/potassium protein pump

carrier protein has space for 3 sodium - phosphate group attaches, carrier changes shape and releases 3 sodium - new shape: can hold 2 potassium - phosphate group releases, carrier back to original shape - releases potassium - repeat

• A form of active transport uses ATP

• Pumps sodium out of the cell, and potassium into the cell 

• For every 3 sodium ions out, 2 potassium ions in

• Used to set up transporting messages along a nerve cell

protein pump

• USES ENERGY (against gradient) 

• Any protein embedded in the cell membrane that pumps ions and solutes across the membrane. 

channel proteins

allow substances to pass through the membrane via a channel

1. Energy NOT required ❌

2. Very SPECIFIC (each protein transports only 1 kind of molecule)

3. NO shape change

4. Ex: Aquaporin moves water molecules faster into the cells

carrier proteins

transport substances by changing shape 

1. Energy IS required ✅ (from ATP - energy storing molecule)

2. Changes shape & interacts to transport across the membrane

3. Also SPECIFIC: (each protein transports only 1 type of molecule)

4. Ex: Sodium & Potassium carrier proteins move sodium and potassium into the cells 

cell recognition proteins

1. Help antibodies identify which cells are foreign invaders or not by telling them that they are part of the body's self-protein (recognize foreign invaders)

2. Ex: Glycoproteins in the cell membrane, carbohydrate on top

receptor proteins

1. has a unique shape that allows a specific molecule to dock at it & it transmits a signal to the cell

   2. Ex: insulin receptor proteins in the liver

enzymatic protein

1. Speed up chemical reactions needed for the cell, substrate -> product

   2. Ex: Membrane enzymes involved in metabolism

junction protein

 holds different membranes together & links cells

integral protein

protein embedded through the membrane

peripheral protein

protein on the edge/side of a membrane

function of cholesterol in membrane

keeps cell strong/holds shape

glycolipids

Lipids that attach to carbohydrate chains

glycoproteins

proteins that attach to carbohydrate chains

function of glycolipids/glycoproteins

tells immune system not to attack tissue (cell recognition)

transport proteins

General term for carrier and channel proteins

types of passive transport

Diffusion, facilitated diffusion (channel proteins), osmosis

types of active transport

Na K pumps, endocytosis, exocytosis, carrier proteins

can diffuse through membrane - protein not required

Small gases (oxygen, carbon dioxide), water, non-charged molecules

cannot diffuse through membrane - protein required

Charged molecules + ions, macromolecules, viruses

salt water/onion lab reaction

After the saline solution was added to the onion, the plant cells shrunk because they were placed in a hypertonic solution, extracting water from the cells.

human cells

0.9% salt, 99.1% water

pump/concentrate (generally)

suggest active transport when discussing transport across the cell membrane.

osmosis occurs towards the

hypertonic solution (low water)

simple diffusion

type of passive transport: substances don’t need transport protein, can diffuse through membrane

why does osmosis flow towards hypertonic solutions?

to reach the equilibrium, to balance water

why do you get dehydrated when consuming salt?

The salt you consume (hypertonic) attracts the water from the body cells (hypotonic) to that salt, resulting in dehydration of your body.