We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are Organelles?

Mary McMahon
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Organelles are tiny structures that perform very specific functions within cells. The term is a reference to organs, likening the way these structures operate in cells to the way organs function in the body. A number of different organelles can be found inside various types of plant, animal, and bacteria cells. Each has its own important task, such as producing energy or manufacturing proteins.


These structures have a wide range of functions, most of which are tasks that are critical to the life of the cell. The most important structures are the nucleus, the endoplasmic reticulum (ER), the Golgi apparatus, mitochondria, and chloroplasts. Each of these tends to be located in specific areas of cells. Typically, the nucleus is located near the center, with the ER and Golgi located nearby, and the remaining organelles spread within the cell.

The type and number of organelles present within a cell varies, depending on the cell's purpose. For example, almost all plant and animal cells contain a nucleus, with the notable exception of mature red blood cells, which do not contain any organelles or genetic material. Another example is that muscle cells typically have many more mitochondria than other cell types, because more energy is required to keep muscle cells working effectively.


Researchers believe that the overall reason that organelles evolved is that cells benefit from isolating the many complex chemical reactions that occur within them. Within plant and animal cells, each one is encased in its own membrane, which helps the unit function. One of the main benefits of this protection is that, within a membrane-enclosed unit, chemical conditions such as pH can be modified without affecting the entire cell. Similarly, the contents of each is isolated from what is occurring within the cell at large.

Certain organelles are so big that their shape and surface can be seen under a light microscope. These include mitochondria and the Golgi, as well as the cell nucleus. An electron microscope is required to view them more closely, however. It was not until these structures could be examined via electron microscopy that researchers began to understand how they functioned.

Energy Production

Mitochondria are responsible for providing cells with usable energy. They are found in most complex organisms, including fungi and plants as well as animals. The main function of these structures is to produce a molecule called adenosine triphosphate, or ATP, which is the main source of energy in animal and fungi cells, and a secondary source for plants. Mitochondria have additional functions as well, including cell metabolism regulation and calcium storage.

Certain organelles are found only within a specific type of organism. The most well-known example is chloroplasts, which are found only in the cells of plants and algae. Chloroplasts use sunlight to produce glucose through the process known as photosynthesis. Another example is the carboxysome, which is found only in certain bacterial species. Carboxysomes allow the bacteria to turn carbon into organic molecules that they can use for energy.

Protein Production and DNA Interactions

Many organelles are able to communicate with one another, either due to their proximity, or via chemical signaling. For instance, the endoplasmic reticulum connects to the Golgi apparatus, and both of these units are involved in the production of new proteins. New proteins are manufactured in the endoplasmic reticulum, and from there, move to the Golgi, where they are modified and packaged for transport to other locations in the cell.

Another example of this communication is that which occurs between the nucleus of a cell and the other organelles within it. Although the nucleus and the DNA it contains do not physically connect with other cell structures, it communicates with the rest of the cell through protein signaling molecules. The membrane that envelops the nucleus controls what can enter and leave the structure, by limiting traffic to special proteins that are able to interact with DNA strands.


Just as the larger organs can be affected by health problems, individual organelles can also be subject to medical conditions and congenital disorders. These structures are so essential for cell function that diseases that affect them often cause severe symptoms and, in some cases, are fatal. Dysfunction can have wide-ranging and unexpected results.

Endoplasmic reticulum dysfunction has been implicated in conditions such as cystic fibrosis, and in Alzheimer’s, Huntington’s, and Parkinson’s diseases. In each case, cellular dysfunction that puts stress on the ER is thought to contribute to the symptoms that develop. Diseases that affect the Golgi include congenital disorders that cause liver disease, mental disability, and seizures, and they typically cause death before a child reaches two years old.

A large family of conditions known as mitochondrial disorders can cause everything from digestive problems to blindness, depending on the specific nature of the disorder that a person is affected by. These conditions can be difficult to treat, as they usually involve congenital defects which cause damage to all of the organelles involved across a given cell type.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a All The Science researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

By anon972092 — On Oct 01, 2014

Between prokaryote and eukaryote have three things in common: they both have cell membranes, ribosomes, cell walls (eukaryote plants have cell walls), and chromosomes.

By anon330548 — On Apr 17, 2013

Cells are more complex than a motor vehicle.

By anon234738 — On Dec 13, 2011

Your motorcycle isn't a living thing, so it can't evolve. People created your motorcycle and may adapt the design to improve its functioning, just as a living thing may adapt to its environment. That doesn't make the information about adaptations religion.

Scientific research proves that living organisms adapt to different climates, food supplies and other conditions and those adaptations may involve changes/evolution at the cellular level.

By anon222809 — On Oct 16, 2011

"These structures have evolved over time to serve specific functions which will further the life of the host organism." My motorcycle doesn't evolve over time, on the contrary, is not a cell more complex than my stuff? How does science prove that organelles have evolved over time? I don't like religion in science teaching.

By catapult43 — On Jan 29, 2011

I was wondering what the relationship was between organelles and the nucleus. And, I found out that the nucleus is an organelle. And, eukaryotic cells (defined by having a nucleus) have organelles, one of which is the nucleus. Just thought I'd share!

By ivanka — On Jan 27, 2011

@purple shark - thanks for the extra info!

I didn't know what a "unit membrane" was -- I thought you might have meant unified membrane -- so I looked it up and in case others wanted to know it's just the name of the membrane. It's also called a cell membrane or a plasma membrane or a plasmalemma.

By PurpleSpark — On Sep 28, 2010

My son had to do a science report on organelles and I helped him with his research. These are some of the things that we learned:

Most organelles are membrane bound, meaning that they have a unit membrane around them.

Some cells will have more of a particular organelle because they enable it to carry its function.

The prokaryotic cells don’t have membrane bound organelles.

Some of the organelles are visible with a strong light microscope.

Mary McMahon

Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.