Farmasevtika instituti farmakologiya va klinik farmatsiya kafedrasi

 
Digestion of Pinocytotic and Phagocytic Foreign Substances Inside the Cell
—
Function of the Lysosomes
Almost immediately after a pinocytotic or phagocytic vesicle appears inside a cell, one or more 
lysosomes
 
become attached to the vesicle and empty their 
acid hydrolases 
to the inside of the vesicle, 
as shown in Figure 2-12. Thus, a 
digestive vesicle 
is formed insidethe cell cytoplasm in which the 
vesicular hydrolases begin hydrolyzing the proteins, carbohydrates, lipids, amino acids, glucose, 
phosphates, and so forth that can diffuse through the membrane of the vesicle into the cytoplasm. What 
is left of the digestive vesicle, called the 
residual body, 
represents indigestible substances. In most 
instances, this is finally excreted through the cell membrane by a process called 
exocytosis, 
which is 

---

essentially the opposite of endocytosis. Thus, the pinocytotic and phagocytic vesicles containing 
lysosomes can be called the 
digestive organs 
of the cells. 
Synthesis and Formation of Cellular Structures by Endoplasmic Reticulum and 
Golgi Apparatus 
Specific Functions of the Endoplasmic Reticulum 
The extensiveness of the endoplasmic 
reticulum and the Golgi apparatus in secretory cells has already been emphasized. These structures are 
formed primarily of lipid bilayer membranes similar to the cell membrane, and their walls are loaded 
with protein enzymes that catalyze the synthesis of many substances required by the cell. Most 
synthesis begins in the endoplasmic reticulum. The products formed there are then passed on to the 
Golgi apparatus, where they are further processed before being released into the cytoplasm. But first, 
let us note the specific products that are synthesized in specific portions of the endoplasmic reticulum 
and the Golgi apparatus.