Cell Organelles III

Cell Organelles

Organelles in cell biology could be termed as the subunit within a cell that is dedicated to performing a specific function. Individual organelles are encompassed within their own lipid bilayers. In simple terms, it is the membrane-bound structure that is present within a cell. Cell fractionation is the process performed to purify cell organelles.

Cell Organelles and their Functions

We know that cells are of two types viz. Eukaryotes and Prokaryotes. Eukaryotes do not possess membrane-bound nuclei, unlike prokaryotes. Below is a brief description of certain vital eukaryotic cell organelles and their functions.

  • Ribosomes

Ribosomes are found in the form of tiny particles in a large number of cells. Each cell contains ribosomes that usually differ in size depending on whether the cell replicates or not. Ribosomes are divided into two types. They are either encompassed within the endoplasmic reticulum or are freely traced in the cell’s cytoplasm. Ribosomal RNA and Ribosomal proteins are the two components that together constitute ribosomes. They are used to synthesize the variety of proteins that ensure the survival of the cell.

  • Golgi Apparatus

Golgi Apparatus also termed as Golgi Complex is a membrane-bound nucleus. Its main function is to modify proteins. That is it searches sequences of amino acid proteins, it identifies specialized codes and makes the required changes. Further, these modified proteins are placed in Golgi so that it can transport elsewhere in the cell when required.

  • Nucleus

Nucleus stores the cell’s DNA and it is one of the largest organelles. Its main function is to monitor all activities of the cell which includes metabolism and growth by making use of DNA’s genetic information. Nucleoli in the nucleus are responsible for the synthesis of protein and RNA. The cell is comprised of only one nucleus but in some cases, the nucleus might split, but the cytoplasm would certainly not.

  • Mitochondria

Mitochondria is termed as the powerhouse of the cell. They are found in almost all eukaryotic cells. They usually vary in size and are either round or oval in shape. Mitochondria help to transform molecules. For instance, glucose is converted into adenosine triphosphate – ATP. The mitochondrial genome is inherited maternally in several organisms.

  • Endoplasmic Reticulum

It is a membranous organelle. A part of the endoplasmic membrane is shared with its membrane. It is found in all eukaryotic cells. The ER is divided into two types based on their physical and functional properties viz. Smooth and Rough ER. The smooth ER is involved in the production of lipids and the rough ER is involved in protein manufacture.

  • Chloroplasts

These are the cell organelles that are found in certain algae and plants. They are indulged in the synthesis and storage of foods. It is a type of a plastid that is either oval, round or disk in shape. Chlorophyll is a pigment that is present in chloroplasts that convert light energy captured from the sun to glucose, carbon -dioxide, and water for food.


Practise This Question

The fluid present between cell membrane and nucleus is called