Cell Functions
Middle School
Definition
The tasks that cells carry out to stay alive, such as taking in nutrients, releasing energy through respiration, removing wastes, growing, and reproducing. Specialised cells also perform particular jobs for the whole organism.
Worked examples
A red blood cell takes in oxygen in the lungs and releases it to body tissues, then carries carbon dioxide waste back to be exhaled.
This shows respiration, nutrient transport, and waste removal — all essential cell functions.
A nerve cell receives signals through its dendrites, processes them, and sends messages along its axon to other cells.
Specialised cells perform particular jobs; neurons transmit information for the organism.
Yeast cells break down glucose through respiration to release energy and produce carbon dioxide and alcohol as wastes.
Taking in nutrients, releasing energy, and removing wastes keep the cell alive.
Common mistakes
- Only animal cells have cell functions; plant cells just make food. → All cells — animal, plant, bacteria — carry out cell functions to stay alive. Every living cell respires, removes wastes, grows, and reproduces, regardless of type.
- Cell functions and cell structures are the same thing. → Cell structures are the parts (organelles); cell functions are the tasks those parts perform. The mitochondrion is a structure; releasing energy through respiration is its function.
Where you'll use it next
You'll apply cell functions when studying organ systems (how groups of specialised cells work together), cellular respiration and photosynthesis in detail, and later in genetics to understand how cells grow and reproduce.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026