Final answer:
Specialized functions in a cell that are bound in a membrane structure are called organelles. These structures are essential for cell operation and include components like the nucleus, mitochondria, and ribosomes which are unique to eukaryotic cells.
Step-by-step explanation:
Each cell performs many specialized functions, and where those specific functions are bound in a membrane structure, they are called organelles. Organelles are the specialized structures within the cytoplasm of a eukaryotic cell that carry out distinct functions necessary for the cell's survival and operation. Examples of organelles include the nucleus, which houses the genetic material; mitochondria, which are responsible for energy production; and ribosomes, which synthesize proteins. The presence of organelles is a defining feature of eukaryotic cells, distinguishing them from prokaryotic cells, which lack membrane-bound organelles.
The cell membrane, which surrounds each cell, is made up of a phospholipid bilayer embedded with proteins and serves as a selective barrier regulating the entry and exit of substances. Organelles also have unique membrane structures that play a key role in their functions, contributing to the overall diversity of cell types and functions within different organisms.