Cell membrane transport

diffusion

the transportation of materials from high concentration to low concentration

Cytoplasm: nutrients, ions, waste, gases, atp

across membrane: depends on permeability

facilitating transport proteins

• Opens door for a single molecule

• channel for diffusion

• bulk ion transport

• monomers absorber

• waste removal

• high to low concentration

Active transport proteins

• Individual molecule is taken through membrane

• uses ATP

• removal of toxins

• concentration of ions

• low to high concentration

Anything bigger to transport though materials

usage of endo and exocytosis through a vesicle ( into or out of)

How to quicken diffusion

better surface area to volume ratio: makes for more diffusion sites

smaller distance: makes for less collisions

increase of temperature: higher kinetic energy makes for more collisions

decrease size: more particles means more collisions

Diffusion vs Osmosis

molecules need to be balanced, if one concentration is higher than it will balance out, if the membrane isn’t permeable for that molecule water balances it.

Tonicitiy

a comparison between solute concentrations between different environments

Hypotonic environments in animal cells

Hypotonic environment: is when water is flowing into cell than the solutes

makes the animal cell burst (lysis)

isotonic environment in animal cells

Equal amount of solute and h2o flowing

no results happen

Hypertonic environments in animal cells.

more water flows out of the cell

results in the cell shrivelling up and causing plasmolysis

Hypotonic environments in plant cells:

More h2o flows into the cell than the solute

resulting in whats called turgur pressure

basically the cell membrane is trying to expand, but the cell wall is rough and holding its shape.

therefore making the plant cell very firm and wont wilt.

isotonic environments in a plant cells

equal flowing results in no net movement and no changes

hypertonic environments in a plant cells

hypertonic is when h2o is flowing out of the cell. making the cell shrivel and wilt.

• in plant cells this is plasmolysis

• plasmolysis is when the cell membrane is shrivelling up and wilting but the cell wall is staying intact therefore its name because the plasma membrane is wilting.

Channel proteins

• open a continues tunnel through the cell membrane

• allow specific molecules or ions to go through passively without changing their shape.

carrier proteins

• transport a specific molecule through the membrane without a tunnel

• a specific molecule binds with the carrier protein to change its shape so it can travel through

• passively or use of ATP

Cell recognition proteins

• typically glycoproteins (proteins with carbohydrates chains attached to it), act as cellular name tags

• allows immune system or other cells to recognize your body cells as “yourself” rather than pathogens or invaders

Receptor proteins

• they have specific shaped binding sites exposed to the outside of the cell

• When external chemical messengers—like hormones—bind to a receptor protein, it triggers a signal transduction pathway, changing internal cell activities

Enzymatic proteins

• membrane embedded enzymes

• directly speed up specific metabolic or chemical reactions at the surface of the membrane