This document provides an overview of cell biology concepts covered in an AP Biology course. It discusses the structures and functions of organelles such as the nucleus, mitochondria, chloroplasts, lysosomes, endoplasmic reticulum, and Golgi apparatus. It explains how cells produce proteins, make energy, digest materials, transport vesicles, and divide. The cytoskeleton and its role in maintaining cell shape, anchoring organelles, and enabling cell motion are also summarized.