Transport in plants occurs over long distances through the vascular system or within cells. Materials move in and out of cells by diffusion, facilitated diffusion, or active transport. Diffusion is a passive, slow movement along a concentration gradient without energy expenditure. Facilitated diffusion uses helper proteins like porins and aquaporins to selectively transport hydrophilic substances without expending energy. Active transport moves substances against a concentration gradient faster than passive transport by utilizing ATP as an energy source.

1. Plant physiology
Transport in plants
by Dr. Ema

2. Translocation- Transport over long distances through
vascular system (Xylem and phloem).

3. Passage of materials in and out of the cell carried out by number of methods-
 Diffusion
 Facilitated diffusion
 Active transport
Means of transport-
Cellular transport / transport in living cell

4. Diffusion –
• Movement of substance along with the concentration gradient
• No energy expenditure
• Movement is passive and slow
• Short distance
Diffusion Rate-
Size of particles
Gradient of concentration
Permeability membrane
separating them
(hydrophobicity)
Temperature
Pressure

5. Facilitated Diffusion-
• Hydrophilicity (finds difficult to pass through the membrane)
• Specific/ selective for uptake
• Helper protein needed called Porin (forms large pores in the outer
membrane of plastide, mitochrondria and bacteria)
• Water channels called aquaporins (8 diff. types)
• Rotation movement and releasing substance inside the cell.
• No energy expenditure

6. • Uniport- when a molecule moves across a membrane independent of
other molecules the process is called as uniport.
• Symport- co-transport where both molecule cross the membrane in the
same direction at the same time.
• Antiport- co-transport where both molecule moves in the opposite
direction.

7. Active transport
• Uphill transport
• Against concentration gradient
• Utilizes ATP as energy
• Faster than passive transport
• Very specific

8. Thank you