1. Cell Structure Chapter 4

2. Cell Theory Robert Hooke was the first to use the word “cells” in living things. Work of Hooke and others created the cell theory

3. 3 Cell size is limited Most cells are small due to reliance diffusion. Rate of diffusion affected by: –Surface area available –Temperature –Concentration gradient –Distance

4. Cell size is limited As a cell’s size increases, its volume increases more rapidly than its surface area. 4

5. Cell Types Inside all cells are small, specialized structures called organelles. Cells are divided into two groups: –Prokaryotes - Eukaryotes

6. 6 Prokaryotes Simplest organisms Archaea and bacteria are prokaryotes. Eukaryotic Complex organisms Plant and animal cells

8. Not all cells are supposed to live Planned cell death is call apoptosis. Programmed into an organism’s development by their DNA.