Tejinder Kaur, Academic Content Creator at Edumarz
Endoplasmic Reticulum:
It is a complex tubular network of membrane bound tubes and sheets which are found exclusively in the eukaryotic cell cytoplasm. Exception : Sperm cell and RBC
It is of two types:
Rough Endoplasmic Reticulum (RER)
Smooth Endoplasmic Reticulum (SER)
Rough Endoplasmic Reticulum (RER) –
The ER has several ribosomes embedded on its outer surface.
It is named so because of its appearance.
Ribosomes are responsible for the synthesis of protein.
RER is prominently observed in cells where protein synthesis happens such as in Liver cells.
Functions:
It is responsible for the synthesis of proteins.
It also plays a role in the folding of proteins and its sorting.
Smooth Endoplasmic Reticulum (SER) –
The ER which does not have ribosomes on its surface.
It is named so because of its smooth appearance.
This SER helps in the production of lipids.
SER is also responsible for transporting the products of RER to other cell organelles such as the Golgi Apparatus.
Functions:
It helps in the synthesis of essential lipids such as Cholesterol.
It is responsible for the synthesis of hormones.
It is the storehouse of Calcium ions which play a role in the nervous and muscular system.
Mitochondria is known as the “powerhouse of the cell”.
It is a double membrane bound cell organelle present in eukaryotic cell cytoplasm that produces the ATP, energy currency of the cell.
Since it is able to make its own DNA and ribosomes, it is called a Semi Autonomous Organelle.
Structure:
It is a double membrane organelle found in both plant and animal cells.
The structure consists of the outer membrane, inner membrane and a gel-like matrix.
Both the outer and inner membrane are separated by Inter membrane space.
The outer membrane has special proteins on its surface called porins.
The inner membrane is folded to form cristae.
The matrix of mitochondria is gel like and consists of enzymes, proteins, ribosomes and organic molecules.
Functions:
It helps in regulating the metabolic activities of the cell.
It promotes cell growth.
It plays an important role in programmed cell death, also known as apoptosis.
It is also involved in cellular respiration.