Anatomy & Physiology
A practical map of the body's structures and systems
Lesson 4 of 20
The cell & organelles
Cells carry out the chemical processes that sustain tissues and organs. A membrane separates the cell from its surroundings and regulates exchange. Organelles perform specialized tasks, from energy conversion to protein production. Cell function depends on coordinated activity rather than any single component.
Key points
- The plasma membrane is a selective boundary made largely of a phospholipid bilayer.
- The nucleus stores most genetic material and helps regulate cell activity.
- Mitochondria generate much of the cell's usable ATP.
- Ribosomes assemble proteins; rough endoplasmic reticulum supports protein processing.
- The Golgi apparatus modifies, sorts, and packages molecules for transport.
Key terms
- Plasma membrane
- Selective boundary regulating exchange between a cell and its environment.
- Nucleus
- Cell compartment containing most DNA and coordinating gene expression.
- Mitochondrion
- Organelle that produces much of a cell's ATP through aerobic metabolism.
- Ribosome
- Structure that links amino acids to build proteins.
- Golgi apparatus
- Organelle that modifies and packages cellular products.
Memory tip
Think of the nucleus as the archive, ribosomes as builders, and Golgi as the shipping center.
Clinical note
Cells differ in shape and organelle abundance according to their specialized roles.
Unit checkpoint
Lock it in: match the terms, then test yourself.