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.

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.

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.

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?

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