WARM UP: What is a microbe? What are the four types of microbes we will be studying? Before we get started: check your agar plates. Make observations on

WARM UP: What is a microbe? What are the four types of

microbes we will be studying?• Before we get started: check your agar

plates. Make observations on your lab sheet. Return your agar plate to the incubator.

• DO NOT OPEN THE LID!!!!!!!

1

2

Introduction to Bacteria

2 TYPES OF BACTERIA:

•Bacteria

-Get food from an outside source

•Blue-green Bacteria

-Make their own food

3

BACTERIA

Bacteria - small one celled monerans

Bacteria like a warm, dark, and moist environment

They are found almost everywhere:

-water -air

-soil -food

-skin -inside the body

-on most objects

4

Spiral:spirilla

rod-shaped: bacilli, bacillus

Round:cocci

3 Shapes of 3 Shapes of BacteriaBacteria

Bacteria are classified by shape into 3 groups:

1. The coccus• The cocci are spherical

or oval bacteria having one of several distinct arrangements based on their planes of division.

• a. Division in one plane produces either a diplococcus or streptococcus arrangement.

• b. Division in two planes produces a tetrad arrangement.

5

1. The coccus• d. Division in

random planes produces a staphylococcus arrangement.

• An average coccus is about 0.5-1.0 micrometer (µm) in diameter. (A micrometer equals 1/1,000,000 of a meter.)

6

2. The rod or bacillus• Bacilli are rod-

shaped bacteria. Bacilli all divide in one plane producing a bacillus, streptobacillus, or coccobacillus arrangement.

• a. bacillus: single bacilli

7

2. The rod or bacillus• b. streptobacillus:

bacilli arranged in chains

• c. a coccobacillus: oval and similar to a coccus

• An average bacillus is 0.5-1.0 µm wide by 1.0-4.0 µm long

8

3. The spiral

• Spirals come in one of three forms, a vibrio, a spirillum, or a spirochete.

• a. vibrio: a curved or comma-shaped rod

• b. spirillum: a thick, rigid spiral

9

3. The spiral

• c. spirochete: a thin, flexible spiral

• Spirals range in size from 1 µm to over 100 µm in length.

10

11

3 Shapes of 3 Shapes of BacteriaBacteria

Bacillus anthracis – (bacillus)

Neisseria meningitidis (coccus)

Leptospira interrogans – (spirilla)

12

7 Major Structures of a Bacteria Cell

•Capsule

•Cell wall

•Ribosomes

•Nucleoid

•Flagella

•Pilli

•Cytoplasm

13

Capsule


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

14

Cell wall


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

15

Ribosomes


cell part where proteins are made

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

16

Nucleoid


a ring made up of DNA

17

Flagella


a whip-like tail that some bacteria have for locomotion

18


Amimation of E.coli

http://www.hybridmedicalanimation.com/pages/jjani_qt/ecoli_qt.html

19

Pilli


hollow hair-like structures made of protein

allows bacteria to attach to other cells.

Pilli-singular Pillus-plural

20

Cytoplasm


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

21

•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

WARM UP:

• What are the three shapes of bacteria?

• What are the 7 major structures of the bacteria?

• DON’T FORGET TO CHECK YOUR AGAR PLATES! DO NOT OPEN THE LIDS!

22

23

BINARY FISSION

Bacteria dividing Completed


http://www.cellsalive.com/cam2.htm

24

•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)


25

Bacterial Cell & Nucleiod DNA Ring

DNA replication

Cell wall synthesis

Cell separation

26

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

27

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

28

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

29

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

30

1

1

1

1

1

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

Harmful Bacteria

31

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

32

1

1

1

1

1

E.coli on small intestines

Helpful Bacteria

33

•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

34

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

35

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

36

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

37

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

http://www.clf.org/gifs/BlueGreen-Algae.jpg

38

1

1

1

1

1

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

39

1

1

1

1

1

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

40

1

1

1

1

1

Leptospira interrogans - spiral shaped prokaryote (spirochete)

41

Ecoli movement animatoin

http://www.hybridmedicalanimation.com/pages/jjani_qt/ecoli_qt.html

Documents

WARM UP: What is a microbe? What are the four types of microbes we will be studying? Before we get started: check your agar plates. Make observations on