Cell Transport

Transport through the cell Membrane
Transport without energy or Passive Transport:

Diffusion - tiny particles like oxygen can move through the gaps in
the cell membrane...the molecules generally move to spread out
evenly

Facilitated Diffusion - just like regular diffusion but molecules move
from high to low concentration by sliding through gap created by
proteins in the cell membrane

Diffusion

Key idea – The main way that small molecules

move across the cell membrane

Diffusion – is a type of passive transport process of molecules moving from an

area of high concentration to an area of lower concentration until they spread out evenly

Diffusion

What causes Diffusion?

- Diffusion is always

happening as molecules
push and bump against
each other in an effort to spread out evenly.

- Moves from high to Low concentration!!

Diffusion of Oxygen
Example: Oxygen in the blood is higher then in a

cell so the oxygen moves into the cell by
diffusing to an area of lower concentration, the
opposite happens as the blood circulates back to the lungs.

Osmosis

Osmosis - The diffusion of water across

a selectively permeable membrane

Key Idea – because cells cannot function

properly without adequate water, many cellular process depend on osmosis

Osmosis

Osmosis and Diffusion

- water spreading from high concentration
to low concentration

Effects of Osmosis
- Effects the size of
cells based on available
water

Active transport

Passive transport – movement of molecules

that does not require energy

Active transport – movement across the cell

membrane that requires energy

4.

Transport through the cell Membrane Transport Using Energy:

Active transport or moving things into the cell that requires energy
with protein is on method of getting resources into the cell...this
occurs when moving things from a low concentration to a high (like moving things uphill)

Two other types of energy required transport are: endocytosis
(moving large particles into the cell) and ectocytosis (moving large particles out of the cell)

Prokaryotes

The prokaryotes are a group of organisms that lack a

cell nucleus or any other membrane-bound
organelles. There are 2 groups Archaea and Bacteria.

Eukaryotes

The presence of a nucleus defines eukaryotes. All species

of large complex organisms are eukaryotes, including animals, plants and fungi, although most species of eukaryote are protist microorganisms.