Unit 5 Cell membrane and transport

PRACTICE FOR SCIENCE 👽👹

Isotonic solution

Equal salt

a solution where the solute concentration and the water concentration is equal to the inside of the cell.

Equal rate of H2O diffusion, cell size stays the same in both animal and plant cells

Hypotonic solution

Less salt

a solution where the H2O concentration is higher than inside the cell

In animal cell, the higher concentration of water on outside of cell enters and bursts cell (cytolysis)

In plant cell the high concentration of water enters the cell and the vacuole enlarges - osmotic pressure and Turgor pressure increases

Hypertonic

More salts

A solution where the H2O concentration is lower than that inside the cell

In animal cell, the high concentration of water in the cell leaves it to the outside and the cell loses water and can shrivel up

In a plant cell, the high concentration of water leaves the cell and the osmotic pressure and turgor pressure decreases, Plasmolysis occurs

Plasmolysis

Cell membrane shrinks with water loss, in plant cells, the cell wilts

As the plant cell loses water in a hypertonic solution,the inner plasma membrane pulls away from the outer cell wall, this happens due to the decrease in turgor pressure and the not-moving rigid cell wall

Osmosis

diffusion of H2O from high to low concentration

No energy required

Water can slowly diffuse across lipid bilayer despite being polar

Selectively permeable membrane

Doesnt allow molecules to pass that are too big or charged molecules

Cytolysis

Process in which a cell has a lower concentration of water, causing an osmotic imbalance in which water rushed in the cell, causing it to burst

Net movement

Overall direction of movement of molecules before equilibrium is reached

Cell membrane

Bilayer, 2 layers of phospholipid

Selectively permeable - allows some molecules in but not others

flexible

Passive/active transport

Passive: No energy needed (high to low)

Active: Energy is needed (low to high)

Concentration gradient

Difference in the concentration of molecules across a space

Equalibrium

Concentration of molecules is qual throughout a space

NO concentration gradient

Molecules move randomly with NO NET movement in one direction

Simple diffusion

Molecules moving from an area of high to low concentration

Sometimes across a phospholipid bilayer

Going down with concentration gradient, no energy required

Facilitated diffusion

Diffusion using the help of MEMBRANE PROTEINS to allow molecules, ions (salts) or slightly larger molecules into and out of cell

Molecules move from high to low concentration

Membrane proteins include: channel protein, carrier protein and aquaporins (transport water only)

What is this (answer up to down)

Phosphate ( hydrophilic head, loves water-polar)

Glycerol

Fatty acid (hydrophilic, hate water, non-polar

Label this:

A, B, C, D, E, F, G, H, I

A: Lipid bilayer

B: phospholipid

C: Hydrophilic heads

D: Hydrophobic tails

E: cholesterol- allow fluidity

F: protein channels

G: carrier proteins

H: Sodium-Potassium pump (nerve cells)

I: Aquaporins (water only)

What is Turgor pressure in a plant cell

Pressure of full vacuol against membrane/ wall

What happens to a sell in a salty enviroment

Hypertonic,vacuole shrinks due to water leaving cell

Does not require energy from the cell

Passive transport

Difference in the concentration of a substance across a space

Concentration gradient

Concentration of a substance is equal throughout a space

Equilibrium

Movement of a substance down the substance's concentration gradient

Diffusion

Diffusion of water through a selectively permeable membrane

Osmosis

Causes a cell to shrink because of osmosis

Hypertonic solution

Causes a cell to swell because of osmosis

Hypotonic solution

Produces no change in cell volume because of osmosis

Isotonic solution

Transport protein through which ions can pass

Ion channel

Protein used to transport specific substances

Carrier protein

Passive transport using carrier proteins

Facilitated diffusion

Movement of a substance against the substance's concentration gradient

Active transport

Carrier protein used in active transport

Sodium-potassium pump

Movement of a substance by a vesicle to the inside of a cell

Endocytosis

Movement of a substance by a vesicle to the outside of a cell

Exocytosis

Endocytosis

Substances pulled in through the membrane

Receptor mediated (type of endocytosis)

Gets specific molecules. Involves binding to specific protein receptor molecules on a cell surface

Exocytosis

Substances pushing out through the membrane

Simple diffusion

Going down with the concentration gradient, no energy required

Transport proteins..

Allow specific ions or molecules to enter and exit cell