Cell Organelles and there functions.

Cytoplasm and its Organelles

Cytoplasm:- Thick, Clear, Jelly-like substance Presend inside the cell Membrance in which cell organelles present.

Cell organelles

1). Endoplasmic Reticulum (ER):- It is a complex series of tubules whose walls are made up of unit membrane through this network of tubules the substances may be delivered from the other membrane of cell proper to the membrane of the nucleus.

Types:-

A). Agranular or Smooth ER

a). Contains no Granules

b). It is the site of steroid synthesis or the site of the detoxification process in other cells

c). It plays important role in Skeletal and Cardiac muscle.

B). Granular or Rough ER:-

a). It Contains Granules called Ribosomes.

b). It is the site of protein synthesis.

c). Free Ribosomes are also found in the cytoplasm that synthesizes cytoplasmic proteins

Example: HB (Haemoglobin)

2). Golgi Complex or Golgi Bodies

A)- It is a collection of membranous tubules and vesicles found always in the neighborhood of the nucleus, prominent in actively secreting gland cells.

B). Golgi bodies are called cell's post office.

Functions:-

A)- Site of formation of lysosomes

B)- It adds carbohydrates to proteins to form glycoproteins which play an important role in the formation of cells to form tissues.

Diagram:-

C)- It involves the transport of material within the cell.

3)- Mitochondrion

A)- Structure:- Lenght 5-12 μm, diameter 0.5-1 μm Globular in shape.

B). Few hundred to few thousands in different cells.

C). Made up of outer membrane and inner membrane.

D). Inner Membrane folded to form cristae(Shelves) which project into the interior of the Mitochondrial.

E)- Outer Membrane-enzymes with biological oxidation.

F). Mitochondrion contains enzymes concerned with 'citric acid cycle and respiratory chain oxidation.

G). Inner membranes contain ATPase and other enzymes related to the synthesis and metabolism of ATP.

The function of Mitochondrion:-

1). Mitochondria are power-generating units of cells and best developed in parts of cells where the energy-requiring processes take place.

example:- Rapidly contraction Skeletal muscle.

2). Also contain DNA and can synthesize proteins.

Diagram:-

4)- Lysosomes:- Large irregular structures surrounded by a unit membrane and are found in cytoplasm 250-70 μm in diameter. The atypical cells may contain several hundred Lysosomes.

It is felled with a large number of small granules 5-8 μm in diameter which contain a variety of enzymes called Lysosomes.

Functions of Lysosomes.

1)- Acts as a form of digestive(lytic) system for the cell because enzymes present it can digest essentially all macromolecules.

2) Phagocytosis:- Engulf Foreign bodies (eg:- Bacteria, Viruses, Fungi, etc)

3)- When a cell dies, Lysosomes enzymes cause autolysis of remnant eg:- that's why Lysosomes are called suicidal Bags.

5). PEROXISOMES:- Its structure is similar to that of Lysosomes.

Functions of Peroxisomes:- They destroy certain products formed from O ₂, especially H ₂O ₂, that can be toxic to the cells, hence the name Peroxisomes(the alcohol, a person drinks is mainly detoxified by peroxisomes of liver cells).

6). Microtubules:-

A). Are long hollow structures about 25 μm in diameter on which chromosomes, Mitochondria, and secretion granules move from one part of the cell to the other part

B). Microfilaments are long solid fibers 4-6 μm in diameter.

C). They have contractile protein actin and are responsible for cell motion.

Diagram:-