mebrane transport and passive transport

Cell membranes are made up of

Bilalayer

Simple diffusion

Slipping directly through the fatty bilayer

Facilitated diffusion

Using a protein doorway

Active transport

Using a protein pump (requires energy)

Vesicle transport

Moving big loads via bubbles (endo/exocytosis)

Concentration gradient

Difference in concentration of a solute across a region

What is is selectively permeable

The cell membrane

Factors affecting permeability

Size of molecules

Chemical nature

Hydrophobic molecules fast or slow pass

Fast

Small, uncharged polar molecules fast or slow pass

Slow pass

Large, uncharged polar molecules fast or slow pass

No pass

Ions are fast or slow pass

No pass (Cl-, K+, Na+)

Passive transport is ___ to ____

High to low

Active transport ___ to _____

Low to high concentration

Osmosis

The specific movement of water

Facilitated diffusion

Using a protein doorwa

Simple diffusion

Slipping through the lipids

Diameter of molecules

Smaller diffuse faster

Temperature of solution

High tempt speed up diffusion

Electric charge of diffusing material

Charged particle slower diffusion

Concentration gradient

Steeper gradients faster diffusion

Dynamic equilibrium

Even when balanced, they moving

Gradient size

A bigger crowd on one side means a faster rush

Molecule mass

Lighter molecules bounce around faster and spread out quickly

Temperature

Heat adds energy and makes molecules bounce faster

Solvent density

Thicker fluids like dehydrated cytoplasm slow things down

Travel distance

The father the journey the slower the process

Diffusion in kidney; selective sorting (filtration)

Small molecules (water, salts) pass through easily

Diffusion in kidney; the barrier

Large molecules (blood cells, proteins) are kept inside

Channel proteins

Open tunnels for a quick passage

Carrier proteins

Revolving doors that bind and carry specific molecules

Ligand as a

Key to a lock

Aquaporins

Channel proteins that allow water to diffuse across the cell membrane at a very high rate

Integral protein

allows for transport

Channel proteins ( high-speed tunnels)

Moves tens of millions of molecules every second

Carrier proteins (the specialized doors )

Move thousands to a million molecules per second

Diffusion of water

Osmosis

Semipermeable membrane

Water flows through, but solutes (like salt) are blocked

Water moves via osmosis

From an area with a hig concentration of water to one of lower concentration

Hypertonic (higher)

The environment around the cell has a higher solute concentration than the cell

Hypotonic (lower)

The environment around the cell has a Lower solute concentration than the cell

Isotonic (similar)

The environment around the cell has the same solute concentration than the cell

Is osmosis hypertonic or hypotonic

Hypertonic; the environment around the cell (outside the cell) has a higher solute concentration than the inside cell

Do cells lose or gain water in osmosis

Lose

Hypotonic definition

The environment around the cell (outside the cell) has a lower solute concentration than the cell

Do cells lose or gain water in hypotonic

Cells gain water

Isontonic definition

Solute concentration s the same inside and outside the cell

Do cells lose or gain water in isotonic

No net water movement across the membrane

Tugor pressure

Water fils the vacuole, pushing the membrane against the wall to keep the plant upright