An organelle is a structure inside a cell that has a specific job. Did you notice that “organelle” has the word “organ” in it? The “-elle” at the end of a word indicates that it is something very small. So organelle literally means “very small organ.”
In our bodies, we have organs — structures that have specific jobs. Kidneys, for instance, remove waste. Cells have organelles that also do specific jobs, just on a smaller scale. Often, organelles are individual sacks of proteins set off from the rest of the cell by a membrane. But sometimes, they are just little clumps of proteins working together in the cell.
One example of an organelle is the nucleus. It stores the cell’s DNA. Chloroplasts are organelles found in plants. It’s where a plant makes sugars.
In a sentence
Eukaryotic cells — like those in animals and plants — use organelles to keep themselves tidy.