Page 62 - Medicinal Plants_PharmD general

Plant Physiology

The science of physiology is concerned with studies of life process
of living organism. Life process or physiological process is chemical or
physical change occurring within a cell or an organism. According to this
definition the following are the essential physiological processes in plants:

1- Photosynthesis.
2- Respiration.
3- Starch synthesis.
4- Protein synthesis.
5- Fat synthesis.

Carbohydrates, proteins and lipids are food reserves or food storage
product which are produced in plant through the basic metabolic pathways.
The majority of vegetable drugs owe their therapeutic activity to secondary
plant product. The production of these secondary metabolites is dependent
on the fundamental metabolic cycles of the living tissue. Pharmacognosists
are particularly interested in the secondary plant products.

The living plant cell possesses a highly organized structure with
various organelles which are:

1- Nucleus.
2- Endoplasmic reticulum ribosomes
3- Mitochondria
4- Chloroplast
5- Vacuole
6- Golgi bodies

These organelles allow the creation of different chemical
environments within one cell, and furthermore, by their structure they
increase the area available for surface reaction. All physiological processes
within the cell are catalysed by specific enzymes which generally speed up
the ratio of reactions.

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