CELL SIZE AND SHAPE PP. 72-73

Cell shape Cell shape reflects function of cell Ex: long extensions of nerve cell send and receive messages Skin cell-flat, plate-like to cover and protect

Why is a cell small? Difficulty exchanging materials (such as nutrients, oxygen, and waste products) across the cell

Why is this important to the cell? Substances cannot get to the center, or out of the center of the cell fast enough if it’s too big

Cell size Cell size is limited by its surface area-to-volume ratio Larger the cell, the volume increases faster than its surface area. Surface area to volume ratio decreases with increasing cell size (EX. 6:1 vs 3:1)

Assignments Transport Practice Diffusion lab or study guide HW: Finish lab (due tomorrow), SG, Cell Model

Summary of the Mini-Lab What was different about the 3 cubes? What happened when we placed the cubes (model cells) in the solution of NaOH? Did the NaOH diffuse the same distance?