Organelle (noun, “OR-gan-ell”)
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.
In a sentence
Eukaryotic cells — like those in animals and plants — use organelles to keep themselves tidy.