unit 4 sav lab

Lab

Unit 4 Lab

Surface Area and Volume

There is one data sheet for this lab

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Print the data sheet to submit via FAX or snail mail , or go HYPERLINK "http /www .cod .edu /people /faculty /fancher /DataSheets .htm " \t "NEW here for a Microsoft Word .doc version which can be submitted as an email attachment

Adapted from an exercise by Helena Mauceri

Size is a very significant parameter of living things . Since a great deal of chemical activity goes on inside any

living cell , a lot of materials are used and produced , and a constant exchange of materials between the interior of the cell and the surrounding environment is essential for the continuation of life . And the size of a cell is vitally connected to its ability to efficiently carry on these negotiations with the environment

Two extremely significant parameters of a cell (or any other object ) are affected by changes in size : the surface area , and the volume . In the case of a cell , the surface area controls the degree to which the cell can "negotiate " with the outside world . The volume controls how much negotiation is required . So the efficiency of the cell is directly affected by the relationship between the amount of surface and the amount of volume : the surface area to volume ratio (SA /V

As an object like a cell increases in size without changing its shape both the surface area and the volume increase . The catch is that the volume , which is a cubed function , increases faster than the surface area , which is a squared function . This has tremendous potential consequences for the survival of the cell . As is discussed in the "Big and Small " essay , this SA /V problem places a practical limitation on the potential size of a cell . If an organism is going to evolve large size various strategies must be employed to get around this problem

Here are some equations which will be useful in completing this exercise

Constants

SA surface area

V volume

H height

W width

L length

SA of a cube H W number of sides

V of a cube H W L

SA to V ratio SA /V

Objectives

The purpose of this lab is to investigate the significance of surface area to volume ratio and its relationship to the size of a cell or an organism

Materials

Calculator

Procedure Cube 1

Cube 2

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Use the data sheet to record your findings

The diagram above shows two cubes . Cube 1 has a side length of 1 cm 2 has a side length of 5 cm . Calculate the surface area (in cm2 ) and volume (in cm3 ) for each of these two cubes . Calculate the SA /V ratio (in cm2 /cm3 ) for each of them (NOTE : the SA /V is divided out - don 't leave it as a fraction ) Record these values on the data sheet

Imagine that a bunch of cubes like Cube...