ER- RA

Slide 1: 

Endoplasmic Reticulum Mrs. RANI ASHOK Assistant Professor of Zoology Lady Doak College, Madurai - 2

THE ANIMAL CELL: 

THE ANIMAL CELL

Discovery: 

Discovery Porten – 1965 Further study – Fawset & Ito, Thiery, Rose and Pomerat

Occurrence: 

Occurrence Varies from cell to cell Egg and embryo – No ER Spermatocytes – Poorly developed Adipose, brown fat cells, adreno cortical cells – smooth/ agranular Pancreas, endocrine glands and other synthetic glandular cells – Granular ER Liver – SER, RER

Morphology: 

Morphology Cisternae Vesicle Tubules 40 – 50 microns Long, flat, sack like, unbranched Pancreas, notochord, brain 25 – 500 microns Oval Membrane bound Vacuolar Abundant in pancreas 50 – 190 microns Branched All cells

Ultra structure: 

Ultra structure Cavities bound by thin membrane of 50 – 60 angstrom thickness Trilaminar Cavity well developed for passage of secretory molecules

Types: 

Types Agranular Granular Annulate/ Lamellae Smooth wall No protein synthesis Seen in: pigmented retinal cell as myeloid body; Glycogen storage cell of liver; Spermatiocytes, Muscle – Sarcoplasmic reticulum Ribosomes attatched Protein synthesis Basophilic and hence called Ergastoplasm. Basophilic bosies and chromophilic substance Nissl bodies is seen No pores/ annuli Seen in: Oocytes & spermatocytes of vertebrates. Has octagonal symmetry Arise by evagination of nuclear membrane Associated with ribosomes

Enzymes contained: 

Enzymes contained Stearases NADH Cytochrome C reductase ATPase etc

Slide 9: 

FUNCTION: transports materials through the cell and makes proteins, water, and other toxic chemicals harmless Network of membrane that connects nuclear envelope to the cell membrane Two types: Soft and Rough

Function: 

Function Secretion, Storage & new synthesis of molecules Skeletal frame work Exchange of molecules Enzymes for synthesis and metabolism Conduct intracellular impulse – sarcoplasmic reticulum New nuclear membrane after the end of mitosis Detoxification process by hypertrophy

Slide 11: 

ROUGH ENDOPLASMIC RETICULUM (RER)

Slide 12: 

ROUGH ENDOPLASMIC RETICULUM (RER)

RER: PROTEIN SYNTHESIS: 

RER: PROTEIN SYNTHESIS

Synthesize: 

Synthesize New proteins Hb Fibrous proteins Serum proteins Enzymes Procollagen

Slide 15: 

SMOOTH ENDOPLASMIC RETICULUM (SER)

SER: LIPID SYNTHESIS: 

SER: LIPID SYNTHESIS

Synthesize: 

Synthesize Lipids Glycogen Steroid compounds Cholesteraol Glycerides Visual pigment

Slide 18: 

FUNCTION: makes proteins Small spherical, black dots Some are free in cytoplasm, others are attached to the ER Ribosomes

RIBOSOMES: 

RIBOSOMES Ribosomes = site of protein synthesis --assembled in the nucleolus --exported into the cytoplasm Free – unbound in the fluid cytoplasm, produce proteins for use in the cell Bound – attached to the endoplasmic reticulum, produce proteins for export or for the plasma membrane

Slide 20: 

Thank You