Page 22 - PG 101-Course notes مذكرة النظري 24-25 with spec
P. 22
Me
Dic Medicinal plants (PG 101) Level 1 Clinical Pharmacy-PharmD
1- Middle Lamella
■ It is the first partition arises between two cells.
■ It made up of mostly of calcium and magnesium pectate.
■ The middle lamella of the new cells comes in contact with the original primary cell
wall layer forming a small cavity and the original cell wall dissolved. The middle lamella
becomes continuous, and the cavity develops as an intracellular space.
2- The primary cell wall
■ This second layer consists mainly of cellulose molecules.
■ It capable of extension as the cell grows.
3- The secondary cell wall
When the cell ceases to enlarge, the protoplast secretes additional substances on the inner
of the primary wall, in the form of successive layers. These layers consist mainly of
cellulose, hemicellulose, lignin (a complex material that is responsible for hardness of
6
