Diffusion

Diffusion is mainly focused on gas particles. It is the net movement of particles from higher concentration to low concentration through partially permeable membrane by random movement, down the concentration gradient. Energy from the diffusion are gained from the kinetic energy of particle movement.

Examples: Gas exchange for respiration, getting rid of waste products.

Factors that influence diffusion

  1. Distance: Shorter Distance, the faster.
  2. Maintain Concentration Gradient, high and low.
  3. Surface Area: The Greater Area, the faster.
  4. Temperature: Higher temperature, the faster.

Osmosis

Osmosis is the movement of water molecules from high level water potential (dilute solution) to low level water potential (concentrated solution) through partially permeable membrane.

Effects of Animal and Plant cells in hyper/hypotonic solutions

Water Potential Animal Cell Plant Cell
Low Water Potential
Hypertonic Solution
(High Concentrated) Diffuse out.
Shrink and crenated. Diffuse out.
Flaccid, floppy
and plasmolysed.
High Water Potential
Hypotonic Solution
(Low Concentrated) Diffuse in.
Swell and burst. Diffuse In.
Becomes turgid
and deplasmolysed.

Active Transport

Active Transport is the movement of ions or larger molecules from low concentration to high concentration by protein carrier using energy from respiration. Example: Root Hair Cell going through Active Transport by allowing nitrate ions to enter.

Chapter Eight: Transport in Plants