What Is An Organelle

What is an organelle?

Expert Answers
lebogar eNotes educator| Certified Educator

Organelles are tiny organs within each cell. Each organelle has a specific structure and function for keeping the cell in a homeostatic state. Plant and animal cells, even though alike in many ways, have a few organelle differences. Prokaryotes and Eukaryotes differ in that prokaryotes have hardly any organelles.

Animal cells have the following organelles:

nucleus - houses the nucleolus, DNA and RNA. It is surrounded by a nuclear membrane that is selectively permeable.

lysosome - this is referred to as a 'suicide sac' because it holds digestive enzymes that aid in recycling waste materials in the cells

vacuole - this houses water and nutrients for the cell

mitochondria - this is commonly referred to as the 'power house' of the cell due to it's ability to break down sugar in order to release energy for cell function. Mitochondrial DNA is housed here.

endoplasmic reticulum - this is a series of tunnel like structures that aid in transportation and ribosome production. There are two types: smooth ER (no ribosomes) and rough ER (ribosomes)

golgi - these organelles package and distribute proteins throughout the cell

ribosomes - these organelles are responsible for protein assemblage. They receive their assembly information from DNA in the nucleus.

The organelles sit in cytoplasm which is a thick nutrient broth in the cell. The cell is surrounded by a membrane that is semi-permeable.

The cell keeps its structure through a series of structures called the cytoskeleton, which also act as a transportation system.

Plant cells have the addition of chloroplasts which are pigmented organelles that aid in photosynthesis. They also have an outer cell wall, made of cellulose, encasing the cell membrane. Their vacuoles are much larger than those found in animal cells.

M.P. Ossa eNotes educator| Certified Educator

I love this question!

An organelle is to a cell what an organ is to a human body. The term "organelle" is basically the same as to say "little organ". This is interesting because, inside of the cell, the organelle operates on its own, using its own protective layer, and allowing the cell to perform specific functions. Similarly in our human body, our organs work in an interdependent way, and on their own, using each their own protective mechanisms and making sure that our bodies are performing to their most optimal condition.

An interesting thing to point out about organelles is that, since they operate within their own protective "compartments", they are often confused in terminology with just about every compartmentalized functioning part of the cell. This means that you have to be careful in understanding that organelles do specific functions that maintain the cell doing its work.

For example, in human cells, the mitochondria produces energy, the Golgi apparatus sorts proteins and modifies them, the vacuole stores and controls the passing of water or other liquids within the cell,  and of course the nucleus of the cell is its "headquarters" or "control center" which stores information.

So, as you can see, the organelle is to the cell (as stated before) the equivalent of what a human organ (such as the heart, lungs, liver, pancreas, etc) is to the human body: They make it work and work to perform basic and important functions.

besure77 eNotes educator| Certified Educator

An organelle is a specialized part of the cell that serves a specific purpose within the cell. There are many organelles present within a cell and they also vary depending on what kind of cell we are talking about, whether it be a plant or animal cell.

Here are a few of the organelles and their functions:

  • nucleus-this would be like the brain of the cell and gives direction to the rest of the cell
  • cell membrane-this provides protection for the cell and allows material to enter and leave the cell
  • vacuoles-these are used for storage of materials such as water
  • mitochondria-this is the powerhouse of the cell-it has ATP (energy)
  • endoplasmic reticulum-this is sort of like circulation for the cell-its use is for transportation

Plant cells have chloroplasts which have chlorophyll and a cell wall.

user2142749 | Student
  1. What is an organelle? What is their purpose? (Give an example)
  2. Describe the important contributions the Human Genome Project has made.
  3. Give one example of genetic engineering that you have heard of Why, again, is DNA important to life? (2 sentences) 
  4. The heads of phospholipids are much different from the tails of phospholipids. How so?

Access hundreds of thousands of answers with a free trial.

Start Free Trial
Ask a Question