Rough endoplasmic reticulam (rer) ( introduction structure & function)

cell organelle rer ppt presented in American University of Barbados

1. ROUGH ENDOPLASMIC RETICULUM BY : Yogesh Vishwakarma Jay Patel Navneet Shukla

2. ENDOPLASMIC RETICULUM Electron microscopic studies of eukaryotic cells reveal the presence of a network or reticulum of tiny tubular structured in the cytoplasm that is called the endoplasmic reticulum . Endoplasmic reticulum divides compartments i.e luminal (Inside ER ) and extra luminal cytoplasm .

3. TYPES OF ENDOPLASMIC RETICULUM ROUGH ENDOPLASMIC RETICULUM SMOOTH ENDOPLASMIC RETICULUM

4. Only found in eukaryotic cells (both animal and plant cell ) . Manufacturing site for lipid and many protein Many of this produced for exported to other organelles . INTRODUCTION

5. Difference between ser and rer SER RER Ribosomes are absent Present near the cell membrane . Formed of tubules . Found in lipid forming cells Eg : Adipocyte , Interstitial cells ,Adrenal cortical cell Leucocyte, Retinal cells . Ribosomes present Present near the nucleus . Formed of cisternae . Found in protein forming cells Eg : Acinal cells , goblet cells , plasma cells , Nissl’s granules , endocrine cells etc .

6. Structure Composed of greatly convoluted but flattish sealed sacs . It is called rough because it is studded on its outer surface with ribosome . About 13 million ribosome are present on the RER in the average liver cell . RER is found throughout the cell but the density is higher near the nucleus and the Golgi apparatus .

7. ROLES OF RER- ORGANELLE IS PRIMARLY CONCERNED WITH SYNTHESIS, FOLDINGS AND MODIFICATION OF PROTEINS. IT PLAYS AN IMPORTANT ROLE IN THE RESPONSE OF THE CELL TO UNFOLDED PROTEINS AND PLAYS A ROLE IN APOPTOSIS, DUE TO ITS CLOSE INTERACTION WITH MITOCHONDRIA. IT PLAYS AN IMPORTANT ROLE IN MODULATING THE RESPONSE OF THE CELL TO STRESS AND IN QUALITY CONTROL FOR CORRECT PROTEIN FOLDING. IT PLAYS NUMBER OF ROLES WITHIN A CELL, LARGELY ASSOCIATED WITH PROTEIN SYNTHESIS.

8. FUNCTION RER working with membrane bound ribosomes they take polypeptides and amino acids from cytosol and make proteins . Protein produced for the plasma membrane , Golgi apparatus , Secretory vesicles , Lysosome , endosome ,and the ER itelf . Certain cells of the pancreas and the digestive tract produced high volume of protein as digestive enzyme.

9. Protein are delivered into the lumen or space inside the ER. In the lumen some proteins have sugar groups added to them to form glycoproteins. Some have metal group added to them .

10. PROTEIN FOLDING UNIT It is in the lumen of the RER that protein are folded to produced the highly important biochemical architecture which will provide ‘Lock & Key’ and other recognition and linking sites.

11. PROTEIN QUALITY CONTROL SECTION It is also take place in lumen of ER Any protein are found incorrectly formed or folded are rejected . The protein is wrongly folded as a result of receiving and altered genetic message . The required protein never exported from the lumen of RER .

12. FROM ROUGH ER TO GOLGI APPARATUS : Protein are transfer to golgi apparatus for finishing . They are conveyed in the vesicles or possibly directly between the ER and Golgi surface . After finishing they are delivered to specific location .

13. ENDOPLASMIC RETICULUM STRESS DISTURBANCE IN THE FUNCTION OF ER LEADS TO EVOLUTIONARILY CONSERVED CELL STRESS RESPONSE , THE UNFOLDED PROTEIN RESPONSE, WHICH IS AIMED AT COMPENSATION FOR DAMAGE BUT CAN TRIGGER CELL DEATH IF THE DYSFUNCTION IS SEVERE OR PROLONGED. ER INITIATED CELL DEATH PATHWAYS HAVE RECOGNIZED SEVERAL DISEASES LIKE-HYPOXIA ISCHEMIA INJURY NEURODEGENERATION HEART DISEASES

14. THANK YOU !