BACTERIA

BACTERIA INFORMATION

Discovered in the late 1600s by Anton van Leeuwenhoek, by accident.

Bacteria are prokaryotes (single celled) Their genetic material is not contained

in a nucleus.

BACTERIAL CELL STRUCTURE

Surrounded by a rigid cell wall. Just inside the cell wall is the cell

membrane. The region inside the cell membrane is

called the cytoplasm. Within the cytoplasm are tiny

structures called ribosomes and the cells genetic material.

May also have a flagellum, which helps with movement.

BACTERIAL CELL

CELL SHAPES

Spherical Rodlike Spiral The chemical makeup of the cell

determines its shape. Shapes, help identify types of bacteria

CELL SIZES

The average size for a bacterial cell is 0.5 to 1 micrometer.

Ecoli Streptococcus

OBTAINING FOOD AND ENERGY

Some bacteria are autotrophs, to eat they Capture the sun’s energy Energy form chemical substances in their

environment . Some bacteria are heterotrophs, to eat

they Consume other organisms Consume food other organisms make Consume a variety of foods from milk and

meat to decaying leaves.

RESPIRATION

Respiration is the process of breaking down food to release its energy.

Most Bacteria need oxygen to break down their food,(Aerobic bacteria)

There are a few kinds of bacteria that few do not need oxygen(Anaerobic bacteria).

REPRODUCTION

When bacteria have plenty of food, the right temperature, and other suitable conditions they thrive and multiply quickly.

Bacteria can reproduce as often as every 20 minutes!

There are three types of bacterial reproduction.

ASEXUAL REPRODUCTION

Asexual reproduction is a reproductive process that involves only one parent and produces offspring that are identical to the parent.

Bacteria reproduce by a form of asexual reproduction called binary fission.

Binary fission means one cell divides to form two identical cells.

Each bacteria has an exact copy of the parent cell’s genetic material

SEXUAL REPRODUCTION

Some bacteria under go simple sexual reproduction, which means two parents combine their genetic material to produce a new organism which is different from the parent cells.

This is called conjugation, when one bacterium transfers some of its genetic material into another bacterium through a thin, threadlike bridge that joints the cells. Figure 10 pg 52

The result is a new bacteria with a new combination of genetic material.

ENDOSPORE FORMATION

Bacteria that live in harsh conditions use the process of forming endospores.

An endospore is a small, rounded, thick-walled resting cell that forms inside a bacterial cell.

It contains the cell’s genetic material and some cytoplasm

Because endospores can resist freezing, heating, and drying they can survive for many years, until if finds a suitable environment, then the bacterial opens up and multiplies.

BACTERIA AND NATURE

Most bacteria are harmless or helpful! Bacteria are involved in oxygen and

food production, environmental recycling and cleanup, and in health maintenance and medicine production.

OXYGEN PRODUCTION

As autotrophic bacteria use the sun’s energy to produce food, they also release oxygen into the air.

FOOD PRODUCTION

Cheese, sauerkraut, pickles, apple cider, milk, buttermilk, yogurt, sour cream all need bacteria.

Bacteria can cause food to spoil by breaking down the food’s chemicals.

Heat Cold Pasteruization

ENVIRONMENTAL RECYCLING

Decomposers Organisms that break down large

chemicals in dead organism into small chemicals.

“Nature’s recyclers” breaking down dead leaves

Nitrogen-fixing bacteria Live in soil Help convert nitrogen gas from the air into

nitrogen products that plants need to grow.

ENVIRONMENTAL CLEANUP

Some bacteria cleanup oils spills in the ocean or gas that leaks into the soil under a gas station.

HEALTH AND MEDICINE

Bacteria help you digest food! Make vitamins for your body. Take the place of disease causing

bacteria Scientist make medicine from bacteria

Human insulin