BacteriaFrom Bacteria to Plants Chapter 2.2

Pages 56-66

Discovery• Believed to be one of the earliest forms of

life on Earth• Undiscovered until the 1600’s– Anton van Leeuwenhoek

Bact Basics• Bacteria are

Prokaryotes: genetic material is not contained in a nucleus– Also lack many other

structures found in cells.

Shape & Structure• Most bacteria have Cell Walls, for protection• Also has…– Cytoplasm that contains genetic material– Ribosomes which produce proteins– Flagellum (flagella) a whip-like structure / tail

used for movement.

Shape & StructureThree basic shapes1. Spherical2. Rod-like3. Spiral shaped• These shapes help

us identify bacteria

Tale of Two KingdomsArchaebacteria

• “Ancient,” having existed for billions of years

• Live in extreme environments – Hot springs– High salinity– High acidity

Eubacteria• Original autotrophs

(produce their own food) that developed our atmosphere

• Live in all non-extreme environments– The surface of any object– On animals– Inside animals

Reproduction• Bacteria reproduce through process

called Binary Fission

• Cell copies its genetic material then divides into two separate cells.

By the Numbers• The average surface in your bathroom

contains about 6,000 bacteria per square inch

• Disinfectants claim to kill 99.9% of germs• This would leave 5 bacteria… not bad• However, average sink space is about 2

square feet – leaving 120 bacteria behind.

By the Numbers

• Under decent conditions, binary fission can take place every 30 minutes

• After an hour, each bacteria will reproduce 2x, creating 480 bacteria

• It will take only 3 hours to create 7,680 bacteria where there was only 5 before.

What to Work On

• Finish reading about Bacteria in your textbook, pages 56-65

• Working as a group, answer the section review questions on page 65 (#’s 1-5)–One answer page per group