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BACTERIA

Bacteria - small one celled

Bacteria like a warm, dark, and moist environment

They are found almost everywhere:

-water -air

-soil -food

-skin -inside the body

-on most objects

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Introduction to EubacteriaCharacteristics of Bacteria

•Autotroph – Make own food through photosynthesis

•Heterotroph - Get food from an outside source

•Unicellular – one cell big

•Prokaryote – cell does not

have a nucleus

•Blue-green Bacteria

•AKA: Cyanobacteria

-Make their own food

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2 TYPES OF Bacteria:

•Bacteria

-Good bacteria: makes food (yogurt, saurkraut, cheese), helps digestion

-Bad bacteria: can cause disease (strep throat, eye infections, pimples, MRSA)

•Blue-green algae

•AKA: Cyanobacteria

-Make their own food through Photosynthesis

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Spiral:spirilla

rod-shaped: bacilli, bacillus

Round:cocci

3 Shapes of 3 Shapes of BacteriaBacteria

Bacteria are classified by shape into 3 groups:

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coccus ROUND Chains:

Pairs:

Clumps:

bacillus ROD

spirillum SPIRAL

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3 Shapes of 3 Shapes of BacteriaBacteria

Bacillus anthracis – (bacillus)

Staphylococcus meningitidis (coccus)

Leptospira interrogans – (spirilla)

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Major Structures of a Bacteria Cell

•Capsule

•Cell wall

•Ribosomes

•DNA

•Flagella

•Cilia

•Cytoplasm

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1. Capsule

7 Major Structures of a Bacteria Cell

keeps the cell from drying out and helps it stick to food or other cells

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2.Cell wall

7 Major Structures of a Bacteria Cell

Thick outer covering that maintains the overall shape of the bacterial cell

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3.Ribosomes

7 Major Structures of a Bacteria Cell

cell part where proteins are made

Ribosomes give the cytoplasm of bacteria a granular appearance in electron micrographs

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4.DNA

7 Major Structures of a Bacteria Cell

controls the Bacteria

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5. Cilia

7 Major Structures of a Bacteria Cell

hollow hair-like structures made of protein

allows bacteria to attach to other cells.

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6.Flagella

7 Major Structures of a Bacteria Cell

a whip-like tail that some bacteria have for movement

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7. Cytoplasm

7 Major Structures of a Bacteria Cell

clear jelly-like material that makes up most of the cell

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•Binary Fission- the process of one organism dividing into two organisms

•Fission is a type of asexual reproduction

Reproduction of Reproduction of BacteriaBacteria

How?...The one main (circular) chromosome makes a copy of itselfThen it divides into two

•Asexual reproduction- reproduction of a living thing from only one parent

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BINARY FISSION

Bacteria dividing Completed

Reproduction of Reproduction of BacteriaBacteria

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•The time of reproduction depends on how desirable the conditions are

•Bacteria can rapidly reproduce themselves in warm, dark, and moist conditions

•Some can reproduce every 20 minutes

(one bacteria could be an ancestor to one million bacteria in six hours)

Reproduction of Reproduction of BacteriaBacteria

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Bacterial Cell & DNA Ring

DNA replication

Cell wall synthesis

Cell separation

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ANTIBIOTICS

Antibiotics- •A chemical substance used to kill or slow the growth of bacteria

•Anti = against

•Antibiotics = against life•Does not kill viruses

•Overused? •Could lead to more resistant bacteria

•Bio = life

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Bacteria Survival

Endospore- •a thick celled structure that forms inside the cell

•they are the major cause of food poisoning

•they can withstand boiling, freezing, and extremely dry conditions•it encloses all the nuclear materials and some cytoplasm

•allows the bacteria to survive for many years

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Bacillus subtilisEndospore-the black section in the middle

highly resistant structures

can withstand radiation, UV light, and boiling at 120oC for 15 minutes.

Bacteria Survival

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Bacteria Survival – Food sources

parasites – bacteria that feed on living things

saprophytes – use dead materials for food (exclusively)

decomposers – get food from breaking down dead matter into simple chemicals

important- because they send minerals and other materials back into the soil so other organisms can use them

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Helpful Bacteria•Decomposers help recycle nutrients into

the soil for other organisms to grow

•Bacteria grow in the stomach of a cow to break down grass and hay

•Most are used to make antibiotics

•Some bacteria help make insulin

•Used to make industrial chemicals

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E.coli on small intestines

Helpful Bacteria

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•Used to treat sewage          

Organic waste is consumed by the bacteria, used as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution, or unsightly mess.

•foods like yogurt, cottage & Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk

Helpful Bacteria

NITROGEN FIXING BACTERIA PRODUCE NITROGEN FOR PLANT TO USE – LEGUMES (BEAN PLANTS)

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Helpful Bacteria

NITROGEN CYCLE

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Harmful Bacteria • some bacteria cause diseases

•Animals can pass diseases to humans

Communicable Disease – Disease passed from one organism to another

This can happen in several ways:•Air•Touching clothing, food, silverware, or toothbrush•Drinking water that contains bacteria

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Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas)

Harmful Bacteria

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Controlling Bacteria3 ways to control

bacteria:1) Canning- the process of sealing food in airtight cans or jars after killing bacteria

•endospores are killed during this process

2) Pasteurization- process of heating milk to kill harmful bacteria

3) Dehydration- removing water from food•Bacteria can’t grow when H2O is

removed •example: uncooked noodles & cold cereal

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Controlling BacteriaAntiseptic vs. Disinfectants

Antiseptic- chemicals that kill bacteria on living things

•means – “against infection”

Examples: iodine, hydrogen peroxide, alcohol, soap, mouthwash

Disinfectants- stronger chemicals that destroy bacteria on objects or nonliving things

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BLUE-GREEN BACTERIAAutotrophs – make their own

food through photosynthesis

commonly grow on water and surfaces that stay wet…such as rivers, creeks and dams

larger than most bacterial cells

Some live in salt water, snow, and acid water of hot springs

food source for animals that live in the water

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BLUE-GREEN BACTERIA

Blooms- occur when the bacteria multiplies in great numbers and form scum on the top of the water

can be toxic to humans and animals