Cells, Organelles, and Their Functions

Cells are the basic building blocks for all organisms. They can be broken down into two types: eukaryotic and prokaryotic cells. Eukaryotic cells are those in which the cells organelles are bounded by a membrane. These can be found in animals, plants, fungi, and protists. Prokaryotic cells do not have distinct organelles. These can be found in prokaryotic organisms. This article will mainly discuss animal cells with organelles.

What are organelles?

As previously mentioned, what differentiates eukaryotic cells are the cells’ organelles are bounded by membranes. The word organelle means “little organ”. This is a great way to think of the microscopic components. Organelles are to cells as organs are to human beings. They are separate entities that carry different functions to ensure the livelihood of the cell. In animal cells, these include the nucleus, mitochondria, ribosomes, the Golgi apparatus, lysosomes, and the vacuole.

The Nucleus

The nucleus is where deoxyribonucleic acid (DNA) is stored and managed. Continuing with the human organs analogy, the nucleus is like the brain of the cell. It chooses which DNA is to be turned on and off and when. DNA contains the instructions for cell reproduction, growth, and survival.

This organelle also contains several sub-organelles. These are the nucleolus, nucleosomes, and chromatins. The nucleus and all its components work together to turn DNA instructions into messenger RNA, which is used to carry out important actions. Animal cells with organelles and all eukaryotic cells contain a nucleus.

The Mitochondria

The mitochondria are the powerhouse of the cell. It is where energy is produced. This occurs through the process of cellular respiration. Sugars and fats are broken down and turned into adenosine triphosphate (ATP). ATP is then utilized by the cell to carry out tasks in all the cell’s organelles.


Ribosomes are tiny organelles found throughout the cell, usually attached to the endoplasmic reticulum, or floating freely through the cytoplasm. They take the messenger RNA created by the nucleus and use its stored information to create polypeptide chains. These polypeptide chains are then synthesized to create proteins.

The endoplasmic reticulum (ER) is a membrane containing connected sacs used to produce, process, and transport proteins. It is located outside of the nucleus. The smooth ER is used as a storage facility for proteins, a synthesizer of lipids, and a remover of waste. The rough ER is where ribosomes are attached.

The Golgi Apparatus

The Golgi apparatus is where recently created proteins from the ER are sorted and packed into vesicles. This organelle is a membrane containing disconnected sacs. The vesicles disperse these proteins to their necessary places throughout the cell.


Lysosomes are a type of vesicle. They are small organelles that aid in digestion, excretion, and cell renewal.

The Vacuole

The vacuole acts as a storage facility for the entire cell. It holds waste, water, food, and other necessary substances.

Other Important Parts

A cell’s organelles play important roles in keeping the cell running smoothly. Some other components that help facilitate this are the cytoplasm and cell membrane.

The cytoplasm is a jelly-like substance that fills the cell. In animal cells with organelles, the organelles would tumble around the cell without this substance. Just imagine how well cell organelles would be able to function if they were flopping all around like coins in your pocket. Then vesicles would never be able to transport proteins to their necessary destinations.

The cell membrane helps the cell keep its shape. It also helps the cell remain separated from other cells and unwanted substances. This object makes sure that nothing enters the cell without permission and that waste is removed as necessary. Like the cytoplasm, it keeps things working properly. Without the cell membrane, cells would be sliding all over the place—in an even worse fashion than if the cytoplasm didn’t exist. Vesicles transporting information could fall to an entirely different part of your body. The membrane ensures that a cell is a single unit.

In summary, cell organelles are what keep things going. Without them, we’d all be prokaryotic bacteria, living extremely simple lives. All these objects can be found in virtually all animal cells with organelles. From skin cells to fat cells, each of these can be found within.


Author: Khaiylah Bustamante