Question

an organelle found in most eukaryotic cells described as \cellular power plants\, because their primary function is to convert organic materials into energy in the form of atp
this is a membrane - bound organelle in eukaryotic cells that is the production and transportation of proteins.
this is any functional structure within the confines of a cell; literally a \small organ\; it usually has a membrane - based structure

Explanation:

1. Mitochondria are known as "cellular power plants" as they convert organic materials into ATP.
2. The endoplasmic - reticulum is involved in protein production and transportation.
3. An organelle is a functional structure in a cell, like a "small organ" with a membrane - based structure.

Answer:

1. Mitochondria
2. Endoplasmic reticulum
3. Organelle