Why do cell walls become brittle when dried?

[Johnleprekan]

Why do cell walls such as in an herb become brittle when dried? What is water doing exactly to hold it together before it was dried?

 

[Drakkith]

I'm no expert, but my little bit of research seems to explain that healthy cells use turgor pressure to remain rigid. Without water the cells cannot use turgor pressure to remain rigid and will wilt.