Introduction to Bacteria 2 TYPES OF BACTERIA Bacteria

Introduction to Bacteria 2 TYPES OF BACTERIA: • Bacteria -Get food from an outside source • Blue-green Bacteria -Make their own food 1

BACTERIA Bacteria - small one celled monerans ØBacteria like a warm, dark, and moist environment They are found almost everywhere: -water -air -soil -food -skin -inside the body -on most objects 2

3 Shapes of Bacteria are classified by shape into 3 groups: Spiral: spirilla rod-shaped: bacilli, bacillus Round: cocci 3

3 Shapes of Bacteria Bacillus anthracis – (bacillus) Neisseria meningitidis (coccus) Leptospira interrogans – (spirilla) 4

7 Major Structures of a Bacteria Cell • Capsule • Cell wall • Ribosomes • Nucleoid • Flagella • Pilli • Cytoplasm 5

7 Major Structures of a Bacteria Cell Capsule Ø keeps the cell from drying out and helps it stick to food or other cells 6

7 Major Structures of a Bacteria Cell wall ØThick outer covering that maintains the overall shape of the bacterial cell 7

7 Major Structures of a Bacteria Cell Ribosomes Ø cell part where proteins are made Ø Ribosomes give the cytoplasm of bacteria a granular appearance in electron micrographs 8

7 Major Structures of a Bacteria Cell Nucleoid Ø a ring made up of DNA 9

7 Major Structures of a Bacteria Cell Flagella Ø a whip-like tail that some bacteria have for locomotion 10

7 Major Structures of a Bacteria Cell Amimation of E. coli 11

7 Major Structures of a Bacteria Cell Pilli Ø hollow hair-like structures made of protein Øallows bacteria to attach to other cells. ØPilli-singular ØPillus-plural 12

7 Major Structures of a Bacteria Cell Cytoplasm Ø clear jelly-like material that makes up most of the cell 13

Reproduction of Bacteria • Binary Fission- the process of one organism dividing into two organisms • Fission is a type of asexual reproduction • Asexual reproduction- reproduction of a living thing from only one parent How? . . . The one main (circular) chromosome makes a copy of itself Then it divides into two 14

Reproduction of Bacteria BINARY FISSION Bacteria dividing Completed 15

Reproduction of Bacteria • 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) 16

Bacterial Cell & Nucleiod DNA Ring DNA replication Cell wall synthesis Cell separation 17

Bacteria Survival Endospore • a thick celled structure that forms inside the cell • they are the major cause of food poisoning • allows the bacteria to survive for many years • they can withstand boiling, freezing, and extremely dry conditions • it encloses all the nuclear materials and some cytoplasm 18

Bacteria Survival Bacillus subtilis Endospore-the black section in the middle vhighly resistant structures vcan withstand radiation, UV light, and 19 boiling at 120 o. C for 15 minutes.

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 üimportant- because they send minerals and other materials back into the soil so 20 other organisms can use them

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 21

Harmful Bacteria Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar 22 (rough areas)

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 23

Helpful Bacteria E. coli on small intestines 24

Helpful Bacteria • Used to treat sewage üOrganic 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 25

Controlling Bacteria 3 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 H 2 O is removed • example: uncooked noodles & cold cereal 26

Controlling Bacteria Antiseptic 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 27

BLUE-GREEN BACTERIA Autotrophs – make their own food through photosynthesis Ølarger than most bacterial cells Øcommonly grow on water and surfaces that stay wet…such as rivers, creeks and dams ØSome live in salt water, snow, and acid water of hot springs Øfood source for animals that live in the 28 water

BLUE-GREEN BACTERIA Øcan be toxic to humans and animals Blooms- occur when the bacteria multiplies in great numbers and form scum on the top of the water 29

Lake Champlain 30

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Bacillus anthracis rod, vegetative stage prokaryote (bacterium) Image Number: 21185 A 33

Neisseria meningitidis - coccus prokaryote (bacterium) Image Number: 97214 E 34

Leptospira interrogans - spiral shaped prokaryote (spirochete) 35

Strep animation http: //www. hybridmedicalanimatio n. com/pages/jjani_qt/strep_pneu mo_qt. html Ecoli movement animatoin http: //www. hybridmedicalanimati on. com/pages/jjani_qt/ecoli_qt. h tml 36

Ecoli movement animatoin http: //www. hybridmedicalanimation. com/pa 37 ges/jjani_qt/ecoli_qt. html

HIV movie http: //www-micro. msb. le. ac. uk/Video/HIV. mov 38

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