Parts of cell organelles. Explain with …

Various components present inside a cell are known as cell organelles. For example plasma membrane, nucleus cytoplasm all are cell organelles.
The plasma membrane also termed as a Cell Membrane or Cytoplasmic Membrane. It is a selectively permeable membrane of the cell, which is composed of a lipid bilayer and proteins.
The cytoplasm is present both in plant and animal cells. They are jelly-like substance, found between the cell membrane and nucleus.  They are mainly composed of water,  organic and inorganic compounds.
The nucleus is a double-membraned organelle found in all eukaryotic cells. It is the largest organelle, which functions as the control centre of the cellular activities and is the storehouse of the cell’s DNA. By structure, the nucleus is dark, round, surrounded by a nuclear membrane. 

Cell organelles are membrane bound little structures that perform activities in the cell. The various cell organelles are – Endoplasmic Reticulum, Ribosomes, Golgi apparatus, Lysosomes, Mitochondria, Plastids, Vacuoles, Peroxisomes and Centrosome.

i. Endoplasmic Reticulum:

The endoplasmic reticulum (ER) is a large network of membrane-bound tubes and sheets which looks like long tubules or round or oblong bags (vesicles). There are two types of ER– rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). RER looks rough under a microscope because it has ribosomes attached to its surface. The ribosomes are the sites of protein manufacture. The SER helps in the manufacture of fat molecules or lipids. Some of these proteins and lipids help in building the cell membrane. This process is known as membrane biogenesis. Some other proteins and lipids function as enzymes and hormones.

ii. Golgi Apparatus:

The Golgi apparatus was first described by Camillo Golgi. Golgi apparatus consists of a set of membrane-bounded, fluid filled vesicles, vacuoles and flattened cisternae. Cisternae are usually stacked together (placed one above the other) in parallel rows. Golgi apparatus exists as an extensive network near the nucleus in the animal cells. However, the plant cells contain many freely distributed subunits of Golgi apparatus, called dictyosomes. The Golgi apparatus arises from the membrane of the smooth endoplasmic reticulum, which in turn, originates from the rough endoplasmic reticulum.