This presentation is the property of its rightful owner.
1 / 13

# By Ms. Chu PowerPoint PPT Presentation

By Ms. Chu. How Quickly Can Bacteria Multiply?. In this imaginary experiment, beans will represent bacterial cells. Put an imaginary bean in an imaginary cup. This bean will represent the first generation of bacteria. 1. How Quickly Can Bacteria Multiply?.

By Ms. Chu

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

By Ms. Chu

### How Quickly Can Bacteria Multiply?

• In this imaginary experiment, beans will represent bacterial cells.

• Put an imaginary bean in an imaginary cup. This bean will represent the first generation of bacteria.

1

### How Quickly Can Bacteria Multiply?

• Approximately every 20 minutes, a bacterial cell reproduces by dividing into two cells.

• Put 2 beans into a second cup to represent the second generation of bacteria.

2

### How Quickly Can Bacteria Multiply?

• Calculate how many bacterial cells there would be in the third generation if each cell in cup 2 divided into two cells.

3

### How Quickly Can Bacteria Multiply?

• Repeat previous step five more times.

• How many cells are in the eighth generation?

• How much time has elapsed since the first generation?

4

32

5

6

64

128

7

8

### How Quickly Can Bacteria Multiply?

• Cup 1 – 1 bacterium

• Cup 2 – 2 bacteria (20 min)

• Cup 3 – 4 bacteria (40 min)

• Cup 4 – 8 bacteria (60 min)

• Cup 5 – 16 bacteria (80 min)

• Cup 6 – 32 bacteria (100 min)

• Cup 7 – 64 bacteria (120 min)

• Cup 8 – 128 bacteria (140 min)

### How Quickly Can Bacteria Multiply?

• From one single bacterium, we got 128 bacteria in the eighth generation!

• And it only took 2h 20 min (140 min) !

Click “play” to view video.

Click “play” to view video.

### The Bacterial Cell Structures

• Cell wall: rigid surrounding of bacterial cell that protects it

• Cell membrane: inside cell wall, controls what materials pass into and out of cell

• Cytoplasm: contains gel-like material

### The Bacterial Cell Structures

• Ribosomes: tiny structures in cytoplasm, chemical factories where proteins are produced

• Genetic material: tangled string looking, inside cytoplasm, contains instructions for cell functions

• Flagella: long, whiplike structures that help a cell to move (singular flagellum)

### The Bacterial Cell Structures

• For more on bacteria, go to:

http://www.phschool.com/webcodes10/index.cfm?wcprefix=ced&wcsuffix=1022&fuseaction=home.gotoWebCode&x=16&y=7