Skip to main content

Endoplasmic reticulum

Name :- Endoplasmic Reticulum (ER)

Properties :
  • ER is a network of tubular and microsomal vesicular structures which is present inside the cell.
  • The tubules and vesicles are interconnected.
  • ER covered by a limiting membrane which is formed by proteins and bilayered lipids.
  • The lumen (diameter - 400 to 700 angstrom) of ER contains a fluid medium called endoplasmic matrix.
  • Total surface area of ER (in some cells like liver cells) can be as much as 30-40 times the cell membrane area.
  • ER forms the link between nucleus and cell membrane by connecting them.

Endoplasmic Reticulum (ER)


Types of ER ....
  1. Rough Endoplasmic Reticulum (RER) / Granular Endoplasmic Reticulum (GER)
  2. Smooth Endoplasmic Reticulum (SER) / Agranular Endoplasmic Reticulum (AER) / Tubular Endoplasmic Reticulum (TER)
1. RER : Rough appearance of ER is due the attachment of ribosomes (granules) to it's outer surface. Hence, it is also celled GER.

Functions :
  •  Synthesis of proteins (specially those proteins which are secreted from the cells like insulin from β - cells, and formation of glycosylated proteins or glycoproteins by adition of carbohydrate with proteins).
  • Degradation of worn-out organelles like mitochondria by autophagosome.
2. SER : ER with smooth appearance. It is formed by many interconnected tubules.

Functions : 
  • Synthesis of non-protein substances like cholesterol, steroid hormones, lipids, phospholipids, lipoprotein and sebum etc.
  • Role in cellular metabolism by it's enzymes which are present outer surface of the ER.
  • Storage and metabolism of calcium.
  • Catabolism and detoxification of toxic substances some drugs and carcinogens (cancer producing substances) in liver.
Similar Posts ....
Labels:

Comments

Post a Comment

Please do not enter any spam link in the comment box

Popular posts from this blog

Histology text & Atlas by Brijesh kumar

Histology text & Atlas by Brijesh kumar Download book pdf About file:- File type - pdf File size - 26.35 MB Pages - 392 Language - English 
Post a Comment
Read more

Lysosomes

Name :- Lysosomes, garbage system of the cell, suicidal bag of the cell Properties : These are membrane bound vesicular structures founds throughout the cytoplasm. These are formed by the process of packaging in the golgi apparatus. Enzymes of lysosomes are synthesized in rough endoplasmic reticulum. Among the organelles, the lysosomes have the thickest covering membrane that is formed by a bilayered lipid material . Lysosomes have 50 different hydrolytic enzymes, known as acid hydroxylases. Types of Lysosomes : Primary lysosomes, this is an inactive of form of lysosomes. Secondary lysosomes, this is an active form of lysosomes (lysosomes active during phagosome or endosome and at this time lysosomes pH become acidic and enzymes are activate). Lysosomal Enzymes :   Proteases :- which hydrolyze the proteins into amino acids. Lipases :- which hydrolyze the lipids into fatty acids and glycerides. Amylases :- which hydrolyze the polysaccharides into glucose. Nucleases :- whi
Post a Comment
Read more

Practical Medicine (P. J. Mehta's)

Practical Medicine (P. J. Mehta's) 20th edition CONTENTS PART-1 CLINICAL CASES 1. History Taking and Symptomatology 2. General Examination 3. Abdomen 4. Respiratory System 5. Cardiovascular System 6. Central Nervous System PART-2 TABLE-WORK 7. Medical Emergencies 8. Electrocardiography 9. Radiology 10. Instruments 11. Procedures 12. Hematology 13. Clinical Pathology 14. Pathology Specimens 15. Drugs ABOUT BOOK Name Book Practical Medicine (P. J. Mehta’s) Author/ Editior (20 th edition) SP Mehta, SR Joshi, Nihar P Mehta / Dr. Hardik shah, Dr. Sunita Iyer, Dr. Nikesh Jain, Dr. Rajiv Shah. Type pdf. Size 69.47 MB Pages 630 Pages type Colored Quality (Good/average/bad) Good D ownload Now Similar Posts :- 1.  Park’s Textbook of PSM 2.  Review of Preventive and Social Medicine (Vivek Jain) 3.  Medicine (Exam Preparatory
Post a Comment
Read more