Lysosomes function

TOPIC# 7 LYSOSOMES

LYSOSOMES

MEANING

Lyso means splitting and soma means body.

INTRODUCTION

Lysosomes are cytoplasmic organelles found in most eukaryotes different from other organelle in morphology(Form and Shape).

They are single membrane bounded organelle and are simple sacs that contain hyrolytic Enzymes(50 types of Enzymes) and Acid phosphatase enzymes.

DISCOVERY:

It was discovered by De Duve in 1949. he called them sucide bags.

SIZE

It is about 0.1-1 micrometer in diameter.

COMPOSITION

Composed of Protein,lipids and Enzymes(class hydrolases)

LOCATION:

They are present in cytoplasm and mostly present in those cells which are active and do phagocytosis(the eating of worn out cells and other cell materials) .

They are abundant iin those cells which exhibit phagocytic activity.e.g Neutrophils,WBCS,macrophages etc.

SYNTHESIS OF LYSOSMES

It is synthesized by RER and modified by Golgf apparatus.

Actually lysosomes are enzymes covered by membrane which are collectively called lysosome.These enzymes are formed by RER and membrane sorrounded from these enzymes done by Golgi apparatus.This is called primary lysosomes but when it hydrolytic or digestive activity it is called as secondary lysosmes or mature lysosomes.

FUNCTION OF LYSOSOME

1- Its main function is digestive activity.

2- when any foreign particle gain entry to cell it is hydrolyse or digested by lysosomes into smaller pieces and this process is called PHAGOCYTOSIS.

3-They also exhibit AUTOPHAGY( The self eating of worn out part of cells.) and in this way materials of cells are recycled and renewed.

4-There enzymes can also result in degeneration of cell ,as may occur during development process.

5-Metomorphosis is also done by lysosomes.

MALFUNCTIONING OF LYSOSOMES

Several congenital diseases have been found due to accumulation of substances such as glycogen and lipids within cell.They are storage diseases caused because of abscence of lysosomal enzymes.

FOR EXAMPLE

1- GLYCOGENOSIS TYPE 2 disease in which the muscle and liver appeared to be filled with glycogen within membrane bounded organelles.

In this disease one enzyme is absent which convert glycogen into glucose.

2-TAY SACS DISEASE in which lipids are accumulated in brain cells lead to mental retardation and even cause death.here also lysosomal enzyme is absent.

IMPORTANT MCQS IN THIS TOPIC

1-Lysosomes are also called as:

Answer: SCAVENGER OR SUICIDE BAGS

2-Lysosomes are sorrounded by _ membranes.

Answer: SINGLE

3-Lysosomes are discovered by:

Answer: DE DUVE

4-Lysosomes are discovered in:

Answer: 1949

5-The diameter of lysosomes is:

Answer: 0.1-1 MICROMETER

6-Lysosomes contain_class of Enzymes: