1. Surface Area and Volume and Cells

2. Cells Shapes The surface area and volume of a cell play an important role in getting enough oxygen and food into the cell.

3. Surface Area The area on the outside of a shape For a cube: add the area of each side of the cube Area = 100 Surface Area = 100+100+100+100+100+100 = 600

4. Volume The space inside the shape Volume = length x width x height On a cube: V = S 3 4 4 4 Volume = 4 x 4 x 4 = 64

5. Example The volume of this set of cubes is 4, assuming each block is equal to 1 cm on a side. The surface area is 16 because we can see 16 sides of the cubes, including the bottom.

6. Try This Build each of the cubes with the blocks and find the surface area and volume. The surface area will equal the number of faces you can see times the area of the side The volume is equal to the number of blocks you use times the volume of each block. Number the problems from 1 – 9 from right to left.

7. Activity Make 3 cubes with the following side lengths: 1 2 3 Complete the following chart: Side LengthSurface AreaVolumeRatio of Surface Area to Volume

8. Pattern for 1 side cube

9. Pattern for 2 side cube

10. Pattern for 3-sided cube

11. Activity Make 3 cubes with the following side lengths: 1 2 3 Complete the following chart: Side LengthSurface AreaVolumeRatio of Surface Area to Volume 16 cm 2 1 cm 3 6/1= 6 224 cm 2 8 cm 3 24/8 = 3 354 cm 2 27 cm 3 54/27 = 2

12. Surface Area/Volume for cells Cells are small because they need a large surface area to volume ratio

13. Cell Size Cells need to exchange gases, bring in food, and get rid of waste If the membrane is too small for the size of the cell, the cell will not survive.

14. Cell Shape The cell shape makes a difference in the ratio of surface area to volume. Long shapes have a greater surface area than square shapes.