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The upcoming discussion will update you about the differences between Primary and Secondary Walls.
Difference # Primary Walls:
1. Primary wall is laid inner to middle lamella.
2. It is formed in young growing cell.
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3. It is capable of extension.
4. The wall grows by intussusception or addition of materials inside.
5. It is single layered.
6. Hydration is 60%.
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7. Cellulose content is comparatively low.
8. Cellulose micro fibrils are shorter, wavy and loosely arranged.
9. Protein content is high, up to 5%.
10. Hemicellulose content is high, up to 50%.
11. Lipid content is 5-10%.
12. Additional chemicals like lignin are absent.
13. Primary wall is thin (0.1-3 µm).
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14. Pits are usually absent in a primary wall.
Difference # Secondary Walls:
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1. Secondary wall is laid inner to primary wall.
2. Secondary wall is formed when the cell has stopped growing.
3. Extensibility is usually absent.
4. It grows by accretion or deposition of materials on the existing structure.
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5. Secondary wall is three or more layered.
6. Hydration is 30—40%.
7. Cellulose content is comparatively high.
8. Cellulose micro fibrils are longer, closely arranged, straight and parallel.
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9. Protein content is low, 1% or less.
10. Hemicellulose content is 25% of the total.
11. Lipid is absent or negligible.
12. Lignin, suberin, etc. are present.
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13 .Secondary walls is quite thick (3-19 µm).
14. Pits often occur in the secondary wall.
