AAT Bioquest

What are the different types of organelles?

Posted August 25, 2022


The different types of organelles include: 


A large membrane-bound organelle, the nucleus houses the cell’s DNA and uses the DNA’s genetic information to regulate most of the cell’s activities including growth and metabolism. DNA replication and RNA transcription occur in the nucleus. 


The nucleolus is a small structure located within the nucleus. It houses the RNA and is the site of ribosome biogenesis.


Known as the powerhouses of the cell, Mitochondria are rod-shaped organelles that perform cellular respiration, converting glucose and oxygen into energy molecules called adenosine triphosphate or ATP. 

Endoplasmic reticulum

The Endoplasmic reticulum (ER) is a membranous organelle composed of multiple interconnected sacs and tubes. It shares part of its membrane with the membrane of the nucleus. There are two types of ER. The rough ER is studded with ribosomes and coordinates protein synthesis. The smooth ER, which lacks ribosomes, is involved in steroid hormone production, lipid synthesis, and detoxification. 


Ribosomes synthesize proteins that are critical to the survival of the cell. They may be found free-floating in the cytosol or embedded in the rough endoplasmic reticulum. 

Golgi apparatus

Made up of multiple sacs of membrane-bound sacs called cisternae, Golgi apparatus is located in close proximity to the endoplasmic reticulum (ER). Raw proteins from the rough ER are transported to the Golgi apparatus, where they are modified. The processed proteins may be packed in vesicles for shipping to other parts of the cell or they may be stored in the Golgi apparatus.  

Cell membrane

The cell membrane is a biological membrane made up of two layers of lipid film. It surrounds the entire cell, separating the interior of the cell from the external environment. In addition to its protective function, the cell membrane also regulates the movements of molecules into and out of the cell. 


All the material encapsulated within the cell membrane, except for the nucleus, is referred to as the cytoplasm. 


Cytosol is a complex cellular fluid that occurs inside the cell and occupies the entire intracellular space. It includes small molecules such as ions, nucleotides, amino acids, sugars, and lipids, as well as macromolecules such as RNA and proteins dissolved in water.  70% of the cytosol is made up of water with the other molecules dissolved in the water making up the remaining 30%. 


Made up of actin filaments, microtubules, and intermediate filaments, the cytoskeleton covers every available space inside the cells, forming the skeleton system. Contraction or expansion of the cytoskeleton results in the cell getting deformed. 


Peroxisome plays a role in breaking down fatty acids to generate energy. Those present in the liver cells facilitate detoxification of substances such as alcohol, drugs, and other chemicals. 


Packed with digestive enzymes, lysosomes function as the cell’s recycling center. They are responsible for breaking down substances into raw materials such as sugars, nucleotides, lipids, and amino acids, which can be used by the cell for building new organelles. Lysosomes are known as suicide bags because of their ability to autolyze and digest their own cell in case of any damage to the cell.

Additional resources

Cell Structures and Organelles

The Role of Organelles in Intestinal Function, Physiology, and Disease