Download 1. Collect data lab. Demo lab about plasmolysis. 2. Definition of

October 22, 2016
Aim: Active transport
Hw. Study for the test Wednesday 9/26. Typed lab report due
10/27
Go over handout hw.
1. Collect data lab. Demo lab about plasmolysis.
2. Definition of active transport
3. Forms of active transport
4. Examples
5. Practice Test
Difussion is caused by molecules moving,
the collision provide the energy
Simple diffusion →
air, liquids and through phospholypid
bilayer
Facilitated diffusion → happens through protein channels.
Mosaic model of the cell membrane
October 22, 2016
Active transport:
Movement of particles from an area of low
concentration to an area of high concentration.
It requires ATP (energy)
The process involves protein pumps and vesicles.
If the process is towards the inside of the cell is
called endocytosis
If the process is towards the outside is called
exocytosis.
A special case of endocytosis is called
• phagocytosis (large particles are ingested)
http://www.ibiblio.org/virtualcell/textbook/chapter3/cmf1.htm
October 22, 2016
To summarize
Passive transport
includes:
Molecules move
high to low concentration
No ATP.
Simple diffusion ( small molecules
such as water, oxygen and CO2), liquids, gasses,
and through phospholypid membrane
Facilitated diffusion: Through protein channels
(Sugars, amino acids, and other medium size molecules)
Osmosis; the movement of water through a semi
permeable membrane. The net movement is affected by
the solution surrounding the cell. (Hypertonic or
Hypotonic solution)
Pump proteins, for example in nerve
cells pumping NA+ and K+ to create
electric charge inside the cell.
Endocytosis
ingestion of substances
Active Transport
Molecules move from
low concentration to high
Requires ATP
Pinocytosis ingestion of
"dissolved" molecules (medium size) n a solution
i
Phagocytosis: Ingestion
of large molecules forming
vesicles.
• Exocytosis
Exocytosis Expulsion of molecules
October 22, 2016