SlideShare a Scribd company logo
Ultra-structure of Endoplasmic reticulum
and functions
Dhole N. A.
Department of Botany,
Digambarrao Bindu ACS College, Bhokar
Endoplasmic Reticulum (ER):
• Within the cytoplasm of most animal cells is an extensive network (reticulum) of
membrane-limited channels, collectively called the endoplasmic reticulum (or ER).
• The endoplasmic reticulum is a name derived from the fact that in the light
microscope it looks like a “net in the cytoplasm.”
• The endoplasmic reticulum is only present in the eukaryotic cells. However, the
occurrence of the endoplasmic reticulum varies from cell to cell.
• For example, the erythrocytes (RBC), egg and embryonic cells lack in the
endoplasmic reticulum.
• Some portion of ER membranes remains continuous with the plasma
membrane and the nuclear envelope.
• ER may be rough or smooth. The outer surface of rough ER has attached
ribosomes, whereas smooth ER does not have attached ribosomes.
• The endoplasmic reticulum acts as secretory, storage, circulatory and nervous
system for the cell. It is also the site of the biogenesis of cellular membranes.
https://microbenotes.com/endoplasmic-reticulum-er-structure-types-functions/
Structure of Endoplasmic Reticulum (ER):
• The membrane of the endoplasmic reticulum is 50 to 60 Aº thickness and
fluid-mosaic like the unit membrane of the plasma membrane.
• The membranes of the endoplasmic reticulum are found to contain many
kinds of enzymes that are needed for various important synthetic activities.
The most important enzymes are the stearases, NADH-cytochrome C
reductase, NADH diaphorase, glucose-6-phosphatase, and Mg++ activated
ATPase.
• The membrane of endoplasmic reticulum remains continuous with the
membranes of the plasma membrane, nuclear membrane, and Golgi
apparatus.
• The cavity of the endoplasmic reticulum is well developed and acts as a
passage for the secretory products.
The endoplasmic reticulum may occur in the following three forms:
1. Lamellar form or cisternae
2. Vesicular form or vesicle and
3. Tubular form or tubules.
The Cisternae:
• RER usually exists as cisternae that occur in those cells which have synthetic
roles as the cells of the pancreas, notochord, and brain.
• The cisternae are long, flattened, sac-like, unbranched tubules having a
diameter of 40 to 50 μm.
• They remain arranged parallelly in bundles or stakes.
The Vesicles:
• The vesicles are oval; membrane-bound vacuolar structures having a
diameter of 25 to 500 μm.
• They often remain isolated in the cytoplasm and occur in most cells but
especially abundant in the SER.
The Tubules:
• The tubules are branched structures forming the reticular system along with
the cisternae and vesicles.
• They usually have a diameter from 50 to 190 μm and occur almost in all the
cells.
• Tubular form of ER is often found in SER and is dynamic in nature, i.e., it is
associated with membrane movements, fission and fusion between
membranes of cytocavity network.
Types of Endoplasmic Reticulum (ER)
1. Smooth Endoplasmic Reticulum
2. Rough Endoplasmic Reticulum
1. Smooth Endoplasmic Reticulum:
• They are also called as the agranular endoplasmic reticulum.
• This type of endoplasmic reticulum possesses smooth walls because the
ribosomes are not attached to its membranes.
• The smooth type of endoplasmic reticulum occurs mostly in those cells,
which are involved in the metabolism of lipids (including steroids) and
glycogen. Eg. adipose cells, interstitial cells, glycogen storing cells of the liver,
conduction fibers of heart, spermatocytes, and leucocytes.
2. Rough Endoplasmic Reticulum:
• It possesses rough walls because the ribosomes remain attached to its
membranes.
• On their membranes, rough ER (RER) contains certain ribosome specific,
transmembrane glycoproteins, called ribophorins I and II, to which are
attached the ribosomes while engaged in polypeptide synthesis.
• The rough type of endoplasmic reticulum is found abundantly in those cells
which are active in protein syntheses such as pancreatic cells, plasma cells,
goblet cells, and liver cells.
Functions:
• Functions of smooth ER include lipid metabolism (both catabolism and anabolism;
they synthesize a variety of phospholipids, cholesterol, and steroids).
• Glycogenolysis (degradation of glycogen; glycogen being polymerized in the
cytosol).
• Drug detoxification (by the help of the cytochrome P-450).
• The endoplasmic reticulum provides an ultrastructural skeletal framework to the
cell and gives mechanical support to the colloidal cytoplasmic matrix.
• The exchange of molecules by the process of osmosis, diffusion and active
transport occurs through the membranes of the endoplasmic reticulum.
• The endoplasmic reticulum is the main component of the endomembrane system, also
called the cytoplasmic vacuolar system or cytocavity network.
• The endoplasmic membranes contain many enzymes that perform various synthetic and
metabolic activities. Further, the endoplasmic reticulum provides an increased surface for
various enzymatic reactions.
• The endoplasmic reticulum acts as an intracellular circulatory or transporting system.
• As a growing secretory polypeptide emerges from the ribosome, it passes through the RER
membrane and gets accumulated in the lumen of RER. Here, the polypeptide chains
undergo tailoring, maturation, and molecular folding to form functional secondary or
tertiary protein molecules.
• RER pinches off certain tiny protein-filled vesicles which ultimately get fused to cis Golgi.
• The ER membranes are found to conduct intra-cellular impulses. For example, the
sarcoplasmic reticulum transmits impulses from the surface membrane into the deep
region of the muscle fibers.
• The ER membranes form the new nuclear envelope after each nuclear division.
• The SER contains several key enzymes that catalyze the synthesis of cholesterol which is
also a precursor substance for the biosynthesis of two types of compounds— the steroid
hormones and bile acids.
• RER also synthesize membrane proteins and glycoproteins which are cotranslationally
inserted into the rough ER membranes. Thus, the endoplasmic reticulum is the site of the
biogenesis of cellular membranes.
References:
• http://www.gcwk.ac.in/econtent_portal/ec/admin/contents/160_18Z
C304%20_2020120306433821.pdf
• https://microbenotes.com/endoplasmic-reticulum-er-structure-
types-functions/
Thank you

More Related Content

What's hot

Quaternary structure of protein By KK Sahu Sir
Quaternary structure of protein By KK Sahu SirQuaternary structure of protein By KK Sahu Sir
Quaternary structure of protein By KK Sahu Sir
KAUSHAL SAHU
 
Cell motility cilia and flagella
Cell motility  cilia and flagellaCell motility  cilia and flagella
Cell motility cilia and flagella
ALLIENU
 
Endoplasmic reticulum class IX
Endoplasmic reticulum class IXEndoplasmic reticulum class IX
Endoplasmic reticulum class IX
Durga Shree
 
Mitochondrial genome
Mitochondrial genomeMitochondrial genome
Mitochondrial genome
GANESHKUMARKOLI
 
Protein targetting
Protein targettingProtein targetting
Supramolecules assembly by kk sahu
Supramolecules assembly by kk sahuSupramolecules assembly by kk sahu
Supramolecules assembly by kk sahu
KAUSHAL SAHU
 
Endoplasmic reticulum- cell Organelle
Endoplasmic reticulum- cell OrganelleEndoplasmic reticulum- cell Organelle
Endoplasmic reticulum- cell Organelle
AshishNain
 
Endoplasmic reticulum
Endoplasmic reticulum Endoplasmic reticulum
Endoplasmic reticulum
SalmaAjmal
 
Diversity of cell shape and size
Diversity of cell shape and sizeDiversity of cell shape and size
Diversity of cell shape and size
Akanksha Golchha
 
Structural organization of Chromosome
Structural organization of Chromosome   Structural organization of Chromosome
Structural organization of Chromosome
HARINATHA REDDY ASWARTHA
 
Eukaryotic chromosome
Eukaryotic chromosomeEukaryotic chromosome
Eukaryotic chromosome
EstherShoba1
 
Protein sorting and targeting
Protein sorting and targetingProtein sorting and targeting
Protein sorting and targeting
KAUSHAL SAHU
 
Nucleus structure and function
Nucleus   structure and functionNucleus   structure and function
Nucleus structure and function
Thippeswamy M
 
Origin of biomolecules.. sairam
Origin of biomolecules.. sairamOrigin of biomolecules.. sairam
Origin of biomolecules.. sairam
Sai Ram
 
Ultrastructure of Nucleus and functions
Ultrastructure of Nucleus and functionsUltrastructure of Nucleus and functions
Ultrastructure of Nucleus and functions
Digambarrao Bindu ACS College, Bhokar
 
Nucleus
NucleusNucleus
Nucleus
Akshay More
 
Peroxisomes
PeroxisomesPeroxisomes
Peroxisomes
Sam Shaikh
 
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATION
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL  REGULATIONCELL CYCLE , MITOSIS ,MEIOSIS AND CELL  REGULATION
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATION
LIFE SCIENCES
 
Cell motility
Cell motilityCell motility
Cell motility
Abdoulwahab Mahde
 
Structure and functions of endoplasmic reticulum
Structure and functions of endoplasmic reticulumStructure and functions of endoplasmic reticulum
Structure and functions of endoplasmic reticulum
ICHHA PURAK
 

What's hot (20)

Quaternary structure of protein By KK Sahu Sir
Quaternary structure of protein By KK Sahu SirQuaternary structure of protein By KK Sahu Sir
Quaternary structure of protein By KK Sahu Sir
 
Cell motility cilia and flagella
Cell motility  cilia and flagellaCell motility  cilia and flagella
Cell motility cilia and flagella
 
Endoplasmic reticulum class IX
Endoplasmic reticulum class IXEndoplasmic reticulum class IX
Endoplasmic reticulum class IX
 
Mitochondrial genome
Mitochondrial genomeMitochondrial genome
Mitochondrial genome
 
Protein targetting
Protein targettingProtein targetting
Protein targetting
 
Supramolecules assembly by kk sahu
Supramolecules assembly by kk sahuSupramolecules assembly by kk sahu
Supramolecules assembly by kk sahu
 
Endoplasmic reticulum- cell Organelle
Endoplasmic reticulum- cell OrganelleEndoplasmic reticulum- cell Organelle
Endoplasmic reticulum- cell Organelle
 
Endoplasmic reticulum
Endoplasmic reticulum Endoplasmic reticulum
Endoplasmic reticulum
 
Diversity of cell shape and size
Diversity of cell shape and sizeDiversity of cell shape and size
Diversity of cell shape and size
 
Structural organization of Chromosome
Structural organization of Chromosome   Structural organization of Chromosome
Structural organization of Chromosome
 
Eukaryotic chromosome
Eukaryotic chromosomeEukaryotic chromosome
Eukaryotic chromosome
 
Protein sorting and targeting
Protein sorting and targetingProtein sorting and targeting
Protein sorting and targeting
 
Nucleus structure and function
Nucleus   structure and functionNucleus   structure and function
Nucleus structure and function
 
Origin of biomolecules.. sairam
Origin of biomolecules.. sairamOrigin of biomolecules.. sairam
Origin of biomolecules.. sairam
 
Ultrastructure of Nucleus and functions
Ultrastructure of Nucleus and functionsUltrastructure of Nucleus and functions
Ultrastructure of Nucleus and functions
 
Nucleus
NucleusNucleus
Nucleus
 
Peroxisomes
PeroxisomesPeroxisomes
Peroxisomes
 
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATION
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL  REGULATIONCELL CYCLE , MITOSIS ,MEIOSIS AND CELL  REGULATION
CELL CYCLE , MITOSIS ,MEIOSIS AND CELL REGULATION
 
Cell motility
Cell motilityCell motility
Cell motility
 
Structure and functions of endoplasmic reticulum
Structure and functions of endoplasmic reticulumStructure and functions of endoplasmic reticulum
Structure and functions of endoplasmic reticulum
 

Similar to Ultrastructure of Endoplasmic reticulum and functions.pptx

Cell Biology Lec 1.ppt
Cell Biology Lec 1.pptCell Biology Lec 1.ppt
Cell Biology Lec 1.ppt
MohamedTharwat970652
 
Cell
CellCell
EUKARYOTIC CELLS PPT BT I.pptx
EUKARYOTIC CELLS PPT BT I.pptxEUKARYOTIC CELLS PPT BT I.pptx
EUKARYOTIC CELLS PPT BT I.pptx
VirionLowry
 
Cell Structure and Function by Dr. Zahoor Mir.pptx
Cell Structure and Function by Dr. Zahoor Mir.pptxCell Structure and Function by Dr. Zahoor Mir.pptx
Cell Structure and Function by Dr. Zahoor Mir.pptx
healthvisionphysioth
 
Cell Structure & Cell Division
Cell Structure & Cell DivisionCell Structure & Cell Division
Cell Structure & Cell Division
Shahin Hameed
 
CELL-the-unit-of-life-8.pptx
CELL-the-unit-of-life-8.pptxCELL-the-unit-of-life-8.pptx
CELL-the-unit-of-life-8.pptx
MUSharavanaPriyan
 
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
Jitendra Bhargav
 
CELL STRUCTURE.pptx
CELL STRUCTURE.pptxCELL STRUCTURE.pptx
CELL STRUCTURE.pptx
VRAGHAVI
 
CELL Biochemistry - new.ppt
CELL Biochemistry - new.pptCELL Biochemistry - new.ppt
CELL Biochemistry - new.ppt
AnnaKhurshid
 
Endoplasmic reticulum.pdf
Endoplasmic reticulum.pdfEndoplasmic reticulum.pdf
Endoplasmic reticulum.pdf
Amity
 
Cell biology
Cell biologyCell biology
Cell biology
MohamedRizwan87
 
CELL Biochemistry.ppt
CELL Biochemistry.pptCELL Biochemistry.ppt
CELL Biochemistry.ppt
AnnaKhurshid
 
Endoplasmic Reticulum and Golgi Apparatus.pptx
Endoplasmic Reticulum and Golgi Apparatus.pptxEndoplasmic Reticulum and Golgi Apparatus.pptx
Endoplasmic Reticulum and Golgi Apparatus.pptx
Abhinav Baranwal
 
Cell: The Unit of Life
Cell: The Unit of LifeCell: The Unit of Life
Cell: The Unit of Life
DrHeenaDevnani
 
Cell the unit of life ncert cell wall to golgi complex
Cell the unit of life ncert  cell wall to golgi complexCell the unit of life ncert  cell wall to golgi complex
Cell the unit of life ncert cell wall to golgi complex
HARINATHA REDDY ASWARTHA
 
the animal cell, parts and functions for students consumption
the animal cell, parts and functions for students consumptionthe animal cell, parts and functions for students consumption
the animal cell, parts and functions for students consumption
Lubega school of health sciences
 
cell.pptx
cell.pptxcell.pptx
cell.pptx
HakeemJawad1
 
Endoplasmic reticulu mppt
Endoplasmic reticulu mpptEndoplasmic reticulu mppt
Endoplasmic reticulu mppt
Genevia Vincent
 
CELLULAR ORGANELLES.pptx
CELLULAR ORGANELLES.pptxCELLULAR ORGANELLES.pptx
CELLULAR ORGANELLES.pptx
AnushkaBais3
 
Cell, the unit of life
Cell, the unit of lifeCell, the unit of life
Cell, the unit of life
pooja singh
 

Similar to Ultrastructure of Endoplasmic reticulum and functions.pptx (20)

Cell Biology Lec 1.ppt
Cell Biology Lec 1.pptCell Biology Lec 1.ppt
Cell Biology Lec 1.ppt
 
Cell
CellCell
Cell
 
EUKARYOTIC CELLS PPT BT I.pptx
EUKARYOTIC CELLS PPT BT I.pptxEUKARYOTIC CELLS PPT BT I.pptx
EUKARYOTIC CELLS PPT BT I.pptx
 
Cell Structure and Function by Dr. Zahoor Mir.pptx
Cell Structure and Function by Dr. Zahoor Mir.pptxCell Structure and Function by Dr. Zahoor Mir.pptx
Cell Structure and Function by Dr. Zahoor Mir.pptx
 
Cell Structure & Cell Division
Cell Structure & Cell DivisionCell Structure & Cell Division
Cell Structure & Cell Division
 
CELL-the-unit-of-life-8.pptx
CELL-the-unit-of-life-8.pptxCELL-the-unit-of-life-8.pptx
CELL-the-unit-of-life-8.pptx
 
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
CELL ANATOMY AND PHYSIOLOGY SLIDESHARE
 
CELL STRUCTURE.pptx
CELL STRUCTURE.pptxCELL STRUCTURE.pptx
CELL STRUCTURE.pptx
 
CELL Biochemistry - new.ppt
CELL Biochemistry - new.pptCELL Biochemistry - new.ppt
CELL Biochemistry - new.ppt
 
Endoplasmic reticulum.pdf
Endoplasmic reticulum.pdfEndoplasmic reticulum.pdf
Endoplasmic reticulum.pdf
 
Cell biology
Cell biologyCell biology
Cell biology
 
CELL Biochemistry.ppt
CELL Biochemistry.pptCELL Biochemistry.ppt
CELL Biochemistry.ppt
 
Endoplasmic Reticulum and Golgi Apparatus.pptx
Endoplasmic Reticulum and Golgi Apparatus.pptxEndoplasmic Reticulum and Golgi Apparatus.pptx
Endoplasmic Reticulum and Golgi Apparatus.pptx
 
Cell: The Unit of Life
Cell: The Unit of LifeCell: The Unit of Life
Cell: The Unit of Life
 
Cell the unit of life ncert cell wall to golgi complex
Cell the unit of life ncert  cell wall to golgi complexCell the unit of life ncert  cell wall to golgi complex
Cell the unit of life ncert cell wall to golgi complex
 
the animal cell, parts and functions for students consumption
the animal cell, parts and functions for students consumptionthe animal cell, parts and functions for students consumption
the animal cell, parts and functions for students consumption
 
cell.pptx
cell.pptxcell.pptx
cell.pptx
 
Endoplasmic reticulu mppt
Endoplasmic reticulu mpptEndoplasmic reticulu mppt
Endoplasmic reticulu mppt
 
CELLULAR ORGANELLES.pptx
CELLULAR ORGANELLES.pptxCELLULAR ORGANELLES.pptx
CELLULAR ORGANELLES.pptx
 
Cell, the unit of life
Cell, the unit of lifeCell, the unit of life
Cell, the unit of life
 

More from Digambarrao Bindu ACS College, Bhokar

Ultra-structure and functions of plasma membrane.pptx
Ultra-structure and functions of plasma membrane.pptxUltra-structure and functions of plasma membrane.pptx
Ultra-structure and functions of plasma membrane.pptx
Digambarrao Bindu ACS College, Bhokar
 
Ultrastructure and functions of Chloroplast.pptx
Ultrastructure and functions of Chloroplast.pptxUltrastructure and functions of Chloroplast.pptx
Ultrastructure and functions of Chloroplast.pptx
Digambarrao Bindu ACS College, Bhokar
 
Ultrastructure of Lysosomes and its functions
Ultrastructure of Lysosomes and its functionsUltrastructure of Lysosomes and its functions
Ultrastructure of Lysosomes and its functions
Digambarrao Bindu ACS College, Bhokar
 
Ultrastructure of Golgi appratus and functions.pptx
Ultrastructure of Golgi appratus and functions.pptxUltrastructure of Golgi appratus and functions.pptx
Ultrastructure of Golgi appratus and functions.pptx
Digambarrao Bindu ACS College, Bhokar
 
Ultra-structure of Ribosomes and functions
Ultra-structure of Ribosomes and functionsUltra-structure of Ribosomes and functions
Ultra-structure of Ribosomes and functions
Digambarrao Bindu ACS College, Bhokar
 
8. Vegetative and sexual reproduction in funaria
8. Vegetative and sexual reproduction in funaria8. Vegetative and sexual reproduction in funaria
8. Vegetative and sexual reproduction in funaria
Digambarrao Bindu ACS College, Bhokar
 
7. Funaria : External morphology and internal structure of axis
7. Funaria : External morphology and internal structure of axis7. Funaria : External morphology and internal structure of axis
7. Funaria : External morphology and internal structure of axis
Digambarrao Bindu ACS College, Bhokar
 
6. Classification and economic importance of bryophytes
6. Classification and economic importance of bryophytes6. Classification and economic importance of bryophytes
6. Classification and economic importance of bryophytes
Digambarrao Bindu ACS College, Bhokar
 
5. Sexual reproduction in marchantia
5. Sexual reproduction in marchantia5. Sexual reproduction in marchantia
5. Sexual reproduction in marchantia
Digambarrao Bindu ACS College, Bhokar
 
2. Marchantia distribution and external features
2. Marchantia distribution and external features2. Marchantia distribution and external features
2. Marchantia distribution and external features
Digambarrao Bindu ACS College, Bhokar
 
1. General characters of bryophytes
1. General characters of bryophytes1. General characters of bryophytes
1. General characters of bryophytes
Digambarrao Bindu ACS College, Bhokar
 
Economic importance of viruses and bacteria
Economic importance of viruses and bacteriaEconomic importance of viruses and bacteria
Economic importance of viruses and bacteria
Digambarrao Bindu ACS College, Bhokar
 
Plant nutrition minor elements
Plant nutrition minor elementsPlant nutrition minor elements
Plant nutrition minor elements
Digambarrao Bindu ACS College, Bhokar
 
Plant nutrition major elements
Plant nutrition major elementsPlant nutrition major elements
Plant nutrition major elements
Digambarrao Bindu ACS College, Bhokar
 
Ascent of sap and transpiration
Ascent of sap and transpirationAscent of sap and transpiration
Ascent of sap and transpiration
Digambarrao Bindu ACS College, Bhokar
 
Plant water relation
Plant water relationPlant water relation
Diffusion, diffusion pressure, diffusion pressure deficit
Diffusion, diffusion pressure, diffusion pressure deficitDiffusion, diffusion pressure, diffusion pressure deficit
Diffusion, diffusion pressure, diffusion pressure deficit
Digambarrao Bindu ACS College, Bhokar
 
7. Economic importance of viruses and bacteria
7. Economic importance of viruses and bacteria7. Economic importance of viruses and bacteria
7. Economic importance of viruses and bacteria
Digambarrao Bindu ACS College, Bhokar
 
6. yellow vein mosaic of bhindi
6.  yellow vein mosaic of bhindi6.  yellow vein mosaic of bhindi
6. yellow vein mosaic of bhindi
Digambarrao Bindu ACS College, Bhokar
 
5. Tobacco mosaic virus
5. Tobacco mosaic virus5. Tobacco mosaic virus
5. Tobacco mosaic virus
Digambarrao Bindu ACS College, Bhokar
 

More from Digambarrao Bindu ACS College, Bhokar (20)

Ultra-structure and functions of plasma membrane.pptx
Ultra-structure and functions of plasma membrane.pptxUltra-structure and functions of plasma membrane.pptx
Ultra-structure and functions of plasma membrane.pptx
 
Ultrastructure and functions of Chloroplast.pptx
Ultrastructure and functions of Chloroplast.pptxUltrastructure and functions of Chloroplast.pptx
Ultrastructure and functions of Chloroplast.pptx
 
Ultrastructure of Lysosomes and its functions
Ultrastructure of Lysosomes and its functionsUltrastructure of Lysosomes and its functions
Ultrastructure of Lysosomes and its functions
 
Ultrastructure of Golgi appratus and functions.pptx
Ultrastructure of Golgi appratus and functions.pptxUltrastructure of Golgi appratus and functions.pptx
Ultrastructure of Golgi appratus and functions.pptx
 
Ultra-structure of Ribosomes and functions
Ultra-structure of Ribosomes and functionsUltra-structure of Ribosomes and functions
Ultra-structure of Ribosomes and functions
 
8. Vegetative and sexual reproduction in funaria
8. Vegetative and sexual reproduction in funaria8. Vegetative and sexual reproduction in funaria
8. Vegetative and sexual reproduction in funaria
 
7. Funaria : External morphology and internal structure of axis
7. Funaria : External morphology and internal structure of axis7. Funaria : External morphology and internal structure of axis
7. Funaria : External morphology and internal structure of axis
 
6. Classification and economic importance of bryophytes
6. Classification and economic importance of bryophytes6. Classification and economic importance of bryophytes
6. Classification and economic importance of bryophytes
 
5. Sexual reproduction in marchantia
5. Sexual reproduction in marchantia5. Sexual reproduction in marchantia
5. Sexual reproduction in marchantia
 
2. Marchantia distribution and external features
2. Marchantia distribution and external features2. Marchantia distribution and external features
2. Marchantia distribution and external features
 
1. General characters of bryophytes
1. General characters of bryophytes1. General characters of bryophytes
1. General characters of bryophytes
 
Economic importance of viruses and bacteria
Economic importance of viruses and bacteriaEconomic importance of viruses and bacteria
Economic importance of viruses and bacteria
 
Plant nutrition minor elements
Plant nutrition minor elementsPlant nutrition minor elements
Plant nutrition minor elements
 
Plant nutrition major elements
Plant nutrition major elementsPlant nutrition major elements
Plant nutrition major elements
 
Ascent of sap and transpiration
Ascent of sap and transpirationAscent of sap and transpiration
Ascent of sap and transpiration
 
Plant water relation
Plant water relationPlant water relation
Plant water relation
 
Diffusion, diffusion pressure, diffusion pressure deficit
Diffusion, diffusion pressure, diffusion pressure deficitDiffusion, diffusion pressure, diffusion pressure deficit
Diffusion, diffusion pressure, diffusion pressure deficit
 
7. Economic importance of viruses and bacteria
7. Economic importance of viruses and bacteria7. Economic importance of viruses and bacteria
7. Economic importance of viruses and bacteria
 
6. yellow vein mosaic of bhindi
6.  yellow vein mosaic of bhindi6.  yellow vein mosaic of bhindi
6. yellow vein mosaic of bhindi
 
5. Tobacco mosaic virus
5. Tobacco mosaic virus5. Tobacco mosaic virus
5. Tobacco mosaic virus
 

Recently uploaded

快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
hozt8xgk
 
Alternate Wetting and Drying - Climate Smart Agriculture
Alternate Wetting and Drying - Climate Smart AgricultureAlternate Wetting and Drying - Climate Smart Agriculture
Alternate Wetting and Drying - Climate Smart Agriculture
International Food Policy Research Institute- South Asia Office
 
HUMAN EYE By-R.M Class 10 phy best digital notes.pdf
HUMAN EYE By-R.M Class 10 phy best digital notes.pdfHUMAN EYE By-R.M Class 10 phy best digital notes.pdf
HUMAN EYE By-R.M Class 10 phy best digital notes.pdf
Ritik83251
 
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Creative-Biolabs
 
Anti-Universe And Emergent Gravity and the Dark Universe
Anti-Universe And Emergent Gravity and the Dark UniverseAnti-Universe And Emergent Gravity and the Dark Universe
Anti-Universe And Emergent Gravity and the Dark Universe
Sérgio Sacani
 
AJAY KUMAR NIET GreNo Guava Project File.pdf
AJAY KUMAR NIET GreNo Guava Project File.pdfAJAY KUMAR NIET GreNo Guava Project File.pdf
AJAY KUMAR NIET GreNo Guava Project File.pdf
AJAY KUMAR
 
23PH301 - Optics - Optical Lenses.pptx
23PH301 - Optics  -  Optical Lenses.pptx23PH301 - Optics  -  Optical Lenses.pptx
23PH301 - Optics - Optical Lenses.pptx
RDhivya6
 
Applied Science: Thermodynamics, Laws & Methodology.pdf
Applied Science: Thermodynamics, Laws & Methodology.pdfApplied Science: Thermodynamics, Laws & Methodology.pdf
Applied Science: Thermodynamics, Laws & Methodology.pdf
University of Hertfordshire
 
8.Isolation of pure cultures and preservation of cultures.pdf
8.Isolation of pure cultures and preservation of cultures.pdf8.Isolation of pure cultures and preservation of cultures.pdf
8.Isolation of pure cultures and preservation of cultures.pdf
by6843629
 
cathode ray oscilloscope and its applications
cathode ray oscilloscope and its applicationscathode ray oscilloscope and its applications
cathode ray oscilloscope and its applications
sandertein
 
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
Advanced-Concepts-Team
 
The cost of acquiring information by natural selection
The cost of acquiring information by natural selectionThe cost of acquiring information by natural selection
The cost of acquiring information by natural selection
Carl Bergstrom
 
Farming systems analysis: what have we learnt?.pptx
Farming systems analysis: what have we learnt?.pptxFarming systems analysis: what have we learnt?.pptx
Farming systems analysis: what have we learnt?.pptx
Frédéric Baudron
 
GBSN - Biochemistry (Unit 6) Chemistry of Proteins
GBSN - Biochemistry (Unit 6) Chemistry of ProteinsGBSN - Biochemistry (Unit 6) Chemistry of Proteins
GBSN - Biochemistry (Unit 6) Chemistry of Proteins
Areesha Ahmad
 
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Sérgio Sacani
 
Compexometric titration/Chelatorphy titration/chelating titration
Compexometric titration/Chelatorphy titration/chelating titrationCompexometric titration/Chelatorphy titration/chelating titration
Compexometric titration/Chelatorphy titration/chelating titration
Vandana Devesh Sharma
 
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
Travis Hills MN
 
11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf
PirithiRaju
 
Sciences of Europe journal No 142 (2024)
Sciences of Europe journal No 142 (2024)Sciences of Europe journal No 142 (2024)
Sciences of Europe journal No 142 (2024)
Sciences of Europe
 
IMPORTANCE OF ALGAE AND ITS BENIFITS.pptx
IMPORTANCE OF ALGAE  AND ITS BENIFITS.pptxIMPORTANCE OF ALGAE  AND ITS BENIFITS.pptx
IMPORTANCE OF ALGAE AND ITS BENIFITS.pptx
OmAle5
 

Recently uploaded (20)

快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
快速办理(UAM毕业证书)马德里自治大学毕业证学位证一模一样
 
Alternate Wetting and Drying - Climate Smart Agriculture
Alternate Wetting and Drying - Climate Smart AgricultureAlternate Wetting and Drying - Climate Smart Agriculture
Alternate Wetting and Drying - Climate Smart Agriculture
 
HUMAN EYE By-R.M Class 10 phy best digital notes.pdf
HUMAN EYE By-R.M Class 10 phy best digital notes.pdfHUMAN EYE By-R.M Class 10 phy best digital notes.pdf
HUMAN EYE By-R.M Class 10 phy best digital notes.pdf
 
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...
 
Anti-Universe And Emergent Gravity and the Dark Universe
Anti-Universe And Emergent Gravity and the Dark UniverseAnti-Universe And Emergent Gravity and the Dark Universe
Anti-Universe And Emergent Gravity and the Dark Universe
 
AJAY KUMAR NIET GreNo Guava Project File.pdf
AJAY KUMAR NIET GreNo Guava Project File.pdfAJAY KUMAR NIET GreNo Guava Project File.pdf
AJAY KUMAR NIET GreNo Guava Project File.pdf
 
23PH301 - Optics - Optical Lenses.pptx
23PH301 - Optics  -  Optical Lenses.pptx23PH301 - Optics  -  Optical Lenses.pptx
23PH301 - Optics - Optical Lenses.pptx
 
Applied Science: Thermodynamics, Laws & Methodology.pdf
Applied Science: Thermodynamics, Laws & Methodology.pdfApplied Science: Thermodynamics, Laws & Methodology.pdf
Applied Science: Thermodynamics, Laws & Methodology.pdf
 
8.Isolation of pure cultures and preservation of cultures.pdf
8.Isolation of pure cultures and preservation of cultures.pdf8.Isolation of pure cultures and preservation of cultures.pdf
8.Isolation of pure cultures and preservation of cultures.pdf
 
cathode ray oscilloscope and its applications
cathode ray oscilloscope and its applicationscathode ray oscilloscope and its applications
cathode ray oscilloscope and its applications
 
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
 
The cost of acquiring information by natural selection
The cost of acquiring information by natural selectionThe cost of acquiring information by natural selection
The cost of acquiring information by natural selection
 
Farming systems analysis: what have we learnt?.pptx
Farming systems analysis: what have we learnt?.pptxFarming systems analysis: what have we learnt?.pptx
Farming systems analysis: what have we learnt?.pptx
 
GBSN - Biochemistry (Unit 6) Chemistry of Proteins
GBSN - Biochemistry (Unit 6) Chemistry of ProteinsGBSN - Biochemistry (Unit 6) Chemistry of Proteins
GBSN - Biochemistry (Unit 6) Chemistry of Proteins
 
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
 
Compexometric titration/Chelatorphy titration/chelating titration
Compexometric titration/Chelatorphy titration/chelating titrationCompexometric titration/Chelatorphy titration/chelating titration
Compexometric titration/Chelatorphy titration/chelating titration
 
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...
 
11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf
 
Sciences of Europe journal No 142 (2024)
Sciences of Europe journal No 142 (2024)Sciences of Europe journal No 142 (2024)
Sciences of Europe journal No 142 (2024)
 
IMPORTANCE OF ALGAE AND ITS BENIFITS.pptx
IMPORTANCE OF ALGAE  AND ITS BENIFITS.pptxIMPORTANCE OF ALGAE  AND ITS BENIFITS.pptx
IMPORTANCE OF ALGAE AND ITS BENIFITS.pptx
 

Ultrastructure of Endoplasmic reticulum and functions.pptx

  • 1. Ultra-structure of Endoplasmic reticulum and functions Dhole N. A. Department of Botany, Digambarrao Bindu ACS College, Bhokar
  • 2. Endoplasmic Reticulum (ER): • Within the cytoplasm of most animal cells is an extensive network (reticulum) of membrane-limited channels, collectively called the endoplasmic reticulum (or ER). • The endoplasmic reticulum is a name derived from the fact that in the light microscope it looks like a “net in the cytoplasm.” • The endoplasmic reticulum is only present in the eukaryotic cells. However, the occurrence of the endoplasmic reticulum varies from cell to cell. • For example, the erythrocytes (RBC), egg and embryonic cells lack in the endoplasmic reticulum.
  • 3. • Some portion of ER membranes remains continuous with the plasma membrane and the nuclear envelope. • ER may be rough or smooth. The outer surface of rough ER has attached ribosomes, whereas smooth ER does not have attached ribosomes. • The endoplasmic reticulum acts as secretory, storage, circulatory and nervous system for the cell. It is also the site of the biogenesis of cellular membranes.
  • 5. Structure of Endoplasmic Reticulum (ER): • The membrane of the endoplasmic reticulum is 50 to 60 Aº thickness and fluid-mosaic like the unit membrane of the plasma membrane. • The membranes of the endoplasmic reticulum are found to contain many kinds of enzymes that are needed for various important synthetic activities. The most important enzymes are the stearases, NADH-cytochrome C reductase, NADH diaphorase, glucose-6-phosphatase, and Mg++ activated ATPase.
  • 6. • The membrane of endoplasmic reticulum remains continuous with the membranes of the plasma membrane, nuclear membrane, and Golgi apparatus. • The cavity of the endoplasmic reticulum is well developed and acts as a passage for the secretory products.
  • 7. The endoplasmic reticulum may occur in the following three forms: 1. Lamellar form or cisternae 2. Vesicular form or vesicle and 3. Tubular form or tubules.
  • 8. The Cisternae: • RER usually exists as cisternae that occur in those cells which have synthetic roles as the cells of the pancreas, notochord, and brain. • The cisternae are long, flattened, sac-like, unbranched tubules having a diameter of 40 to 50 μm. • They remain arranged parallelly in bundles or stakes.
  • 9. The Vesicles: • The vesicles are oval; membrane-bound vacuolar structures having a diameter of 25 to 500 μm. • They often remain isolated in the cytoplasm and occur in most cells but especially abundant in the SER.
  • 10. The Tubules: • The tubules are branched structures forming the reticular system along with the cisternae and vesicles. • They usually have a diameter from 50 to 190 μm and occur almost in all the cells. • Tubular form of ER is often found in SER and is dynamic in nature, i.e., it is associated with membrane movements, fission and fusion between membranes of cytocavity network.
  • 11. Types of Endoplasmic Reticulum (ER) 1. Smooth Endoplasmic Reticulum 2. Rough Endoplasmic Reticulum
  • 12. 1. Smooth Endoplasmic Reticulum: • They are also called as the agranular endoplasmic reticulum. • This type of endoplasmic reticulum possesses smooth walls because the ribosomes are not attached to its membranes. • The smooth type of endoplasmic reticulum occurs mostly in those cells, which are involved in the metabolism of lipids (including steroids) and glycogen. Eg. adipose cells, interstitial cells, glycogen storing cells of the liver, conduction fibers of heart, spermatocytes, and leucocytes.
  • 13. 2. Rough Endoplasmic Reticulum: • It possesses rough walls because the ribosomes remain attached to its membranes. • On their membranes, rough ER (RER) contains certain ribosome specific, transmembrane glycoproteins, called ribophorins I and II, to which are attached the ribosomes while engaged in polypeptide synthesis. • The rough type of endoplasmic reticulum is found abundantly in those cells which are active in protein syntheses such as pancreatic cells, plasma cells, goblet cells, and liver cells.
  • 14. Functions: • Functions of smooth ER include lipid metabolism (both catabolism and anabolism; they synthesize a variety of phospholipids, cholesterol, and steroids). • Glycogenolysis (degradation of glycogen; glycogen being polymerized in the cytosol). • Drug detoxification (by the help of the cytochrome P-450). • The endoplasmic reticulum provides an ultrastructural skeletal framework to the cell and gives mechanical support to the colloidal cytoplasmic matrix. • The exchange of molecules by the process of osmosis, diffusion and active transport occurs through the membranes of the endoplasmic reticulum.
  • 15. • The endoplasmic reticulum is the main component of the endomembrane system, also called the cytoplasmic vacuolar system or cytocavity network. • The endoplasmic membranes contain many enzymes that perform various synthetic and metabolic activities. Further, the endoplasmic reticulum provides an increased surface for various enzymatic reactions. • The endoplasmic reticulum acts as an intracellular circulatory or transporting system. • As a growing secretory polypeptide emerges from the ribosome, it passes through the RER membrane and gets accumulated in the lumen of RER. Here, the polypeptide chains undergo tailoring, maturation, and molecular folding to form functional secondary or tertiary protein molecules.
  • 16. • RER pinches off certain tiny protein-filled vesicles which ultimately get fused to cis Golgi. • The ER membranes are found to conduct intra-cellular impulses. For example, the sarcoplasmic reticulum transmits impulses from the surface membrane into the deep region of the muscle fibers. • The ER membranes form the new nuclear envelope after each nuclear division. • The SER contains several key enzymes that catalyze the synthesis of cholesterol which is also a precursor substance for the biosynthesis of two types of compounds— the steroid hormones and bile acids. • RER also synthesize membrane proteins and glycoproteins which are cotranslationally inserted into the rough ER membranes. Thus, the endoplasmic reticulum is the site of the biogenesis of cellular membranes.