UPTAKE OF NUTRIENTS BY CELL THROUGH PASSIVE TRANSPORT

1. To:
Dr. N. Karthik
Assistant Professor
Department of Microbiology
Sacred Heart college, Tirupattur.
Presented by:
SALOMI V (BP211509)
I M.sc Applied Microbiology
Department of Microbiology
Sacred Heart college, Tirupattur.
UPTAKE OF NUTIENTS BY CELLS:
PASSIVE TRANSPORT

2. PASSIVE TRANSPORT / UPTAKE
In passive process substances cross the membrane from
an area of higher concentration to an area of lower
concentration by the cell.
There are three forms of passive uptake /
transport.
1. Simple diffusion
2. Facilitated diffusion
3. Osmosis

3. 1. SIMPLE DIFFUSION

4. 2. Facilitated Diffusion
Facilitated Diffusion is that molecules move from high solute concentration to low solute concentration
through a protein channel.
The movement of larger molecules like glucose through the cell membrane – larger molecules must be
“helped”.
NO ENERGY IS NEEDED = PASSIVE TRANSPORT
 Facilitated Diffusion in Prokaryotes
EXAMPLE: Glycerol EXAMPLE: Suger, Aminoacid & Vitamins
( Non- specific transport) (specific transprot)
 Facilitated Diffusion in Eukaryotes

5. 3.Osmosis
Osmosis is the net movement of solvent molecules across a
selectively permeable membrane from an area with a high
concentration to an area of low concentration.
Water crosses cell membrane via special channels called
“Aquaporins”.
Osmosis : Diffusion of water.

6. ISOTONIC SOLUTION
 Water concentration is equal inside and outside the cell, thus rates
of diffusion are equal in both directions.
 No net moment of water.

7. Hypotonic solution
 Water moves into the cell.
 If the Cell wall is strong, the cell swells and
 If the cell is weak or damage, the cell bursts (Osmotic lysis).

8. Hypertonic solution
 Water moves out of the cell and
 the cell becomes shrink (Plasmolysis).