HKDSE Biology - Diffusion
Compulsory Part I Cells and Molecules of Life
Account for the movement of substances across membrane using the concepts of diffusion.
Diffusion referring to the net movement of molecules from higher concentration region to lower concentration region ⏩ down the concentration gradient.
Besides, diffusion is one of the passive transport which do not require energy.
Mechanism of simple diffusion
👆🏻This photo illustrated how diffusion assist the transport of molecules through cell membrane.
Simple diffusion 👉🏻 transport of molecules that can be dissolved in lipid bilayer (non-polar).
Mechanism of facilitated diffusion
👆🏻This photo showing diffusion occurred in channel protein
Facilitated diffusion 👉🏻 transport of molecules that cannot be dissolved in lipid bilayer (polar).
Example of diffusion 🔅
Factors influencing the rate of diffusion 🧭
As a HKDSE Biology student, remember how to speed up the rate of diffusion ❗️ ❕
1. Concentration gradient
2. Molecular size
3. Solubility in lipid
4. Sate of molecule
7. Surface area
8. Nature of diffusion surface
That's the end of this topic 👏🏻
Written by Bella | HKDSE Biology Specialist @ TUTTEE
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