Polymorphism in lysosomes, Biology

Polymorphism in Lysosomes

Polymorphism, i.e. existence of a structure in more than one form, is an important feature of lysosomes. Several different forms of lysosomes have been identified within the cell as primary lysosomes, secondary lysosomes, residual bodies and autophagic vacuoles

Primary lysosomes: These are newly formed organelles. They are believed to be derived from the maturing face of Golgi complex whose digestive enzymes have not yet taken part in hydrolysis.

Secondary lysosomes: are formed from fusion of primary lysosomes with the vesicles containing variety of substrates known as 'phagosome'. After fusion, their membrane undergoes a change and enzymes are activated so that the substrate is digested. After activation they may continue hydl-oiysis repeatedly. The secondary lysosomes which fuse. with vesicles containing extracellular substrite brought into the cell by endocytosis are known as heterophagic lysosomes or heterophagosome whereas lysosomes fusing with vesicles containing particles isola~cdf rom cell's own cytoplasm like mitochondria, microbodies, and fragments of endoplasmic reticulum are known as autophagic vacuoles. During pathological conditions or during cell growth, autodigestion of cellular organelles is a normal event.

Residual bodies:
lncomplete digestion of foreign substances leads to the formation of residual bodies. Residual bodies are huge, irregular in shape and are electron dense. In some cells they remain for a long time and play a role in the aging process. In some other cells, the content of the residual bodies leave the cell by exocytosis.

Lysosomes are responsible for the .intracellular digestion of a variety of substances such as food molecules, disease causing organisms, etc. This process is called heterophagy. Lysosomes are also responsible for digestion of cell's own cytoplasmic constituents. This process is called autophagy. It is important that lysosomes do not rupture and release their contents inside living cells as they would start digesting the cell and cell will die.

Posted Date: 12/10/2012 2:41:18 AM | Location : United States







Related Discussions:- Polymorphism in lysosomes, Assignment Help, Ask Question on Polymorphism in lysosomes, Get Answer, Expert's Help, Polymorphism in lysosomes Discussions

Write discussion on Polymorphism in lysosomes
Your posts are moderated
Related Questions
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

List structures found in unicellular organisms that are an adaptation to their free-living life and are not usually found in the cells of multicellular organisms.

Explain Trapezoidal Full Mucoperiosteal Flaps a) Similar to rectangular flap except: The 2 vertical incisions are at obtuse angle with the Horizontal incision, b) Mostly

Products of Cleavage (Morula and blastula) In several cases, the blastomeres in early cleaving stages tend to presume spherical shape like that of the egg earlier than cleava

How do normal flora protect against infection? a. Compete for space and nutrients with pathogens b. Release antimicrobial agents to kill pathogens c. Contribute to host health by p

Sporozoans – Protozoan Sporozoans of the genus Plasmodium are responsible for causing a serious human disease, malaria. They are among, the best known parasites which live in

Explain cardiac examination auscultation and its techniques? Auscultation of the heart sound and associatcd sound is very important to diagnose the cardiovascular diseases. It

Explain the Deficiency and Toxicity of vitamin A? Who defines VAD as tissue concentrations of vitamin A low enough to have adverse health consequences even if there is no evide

Cell culture products: Animal cell cultures are used to generate virus vaccines, as well as different kind  of useful biochemical which are mainly high molecular weight prote

Q. High Para-sternal or Ductal View? This view is obtained by sliding transducer one or two spaces upward and medially from PLAX view. This view is specifically used to vi