Chapter 17 1

VOCABULARY Aerobic respiration Antibiotic Antiseptic Bacterial culture Binary fission Conjugation Classification Disinfectant Ecological role Fermentation Motility Mutation Prokaryote Resistant/resistance 2

READING Basic structure of prokaryotic cell – p Unifying characteristics – p Form, distribution, motility, ecological role, nutrition, human diseases – p , Fermentation, aerobic respiration, photosynthesis in Monerans – p How bacterial decomposers and parasites obtain their food – p.365 Antibiotics, disinfectants, antiseptics – p.374 Antibiotic resistance – p.368 Beneficial roles – p

4 THE FIVE KINGDOMS

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

6 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

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

8 3 Shapes of Bacteria Bacillus anthracis – (bacillus) Neisseria meningitidis (coccus) Leptospira interrogans – (spirilla)

9 7 Major Structures of a Bacteria Cell Capsule Cell wall Ribosomes Nucleoid Flagella Pilli Cytoplasm

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

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

12 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

13 Nucleoid 7 Major Structures of a Bacteria Cell  a ring made up of DNA

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

15 Pilli 7 Major Structures of a Bacteria Cell  hollow hair-like structures made of protein  allows bacteria to attach to other cells.  Pilli-singular  Pillus-plural

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

Bacteria Reproduce Quickly In optimal conditions, an E. coli bacteria can double every 20 minutes. The time it takes a bacteria to double is known as the Generation time

A Growth Table Time (min)# of E. Coli Time (min)# of E. Coli

At just over 6.5 hours you have over 1 MILLION E. coli. Imagine that growing on your sandwich

This type of growth has a special name. It is known as Exponential growth. Exponential growth starts out slow but once it gets going it grows quickly.

Lets Graph it! Time # o f E. c o l i

Time (min) # o f E. c o l i # of E. coli versus Time

Salmonella Salmonella has a generation time of about 30 minutes It can be found on chicken and can make you quite sick. Luckily it takes about 10 million of them to get sick so that’s quite a few.

Lets calculate how long it takes for bacteria to reach 10,000,000 if we have 1000 on our chicken sandwich.

The Special Equation There is a special equation to use with exponential growth N = N 0 2 t/T N = is the number of bacteria N 0 = the number of bacteria you start with T = the amount of time it takes to double t = the actual time

In ideal optimal conditions in about 3 days bacteria could reproduce sooooo much that they would weigh more than our planet.

Lucky for us Lucky for us those conditions don’t usually exist, and a graph of bacterial growth generally looks like this

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

30 BINARY FISSION Bacteria dividing Completed Reproduction of Bacteria

31 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 Bacteria

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

33 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

34 Bacillus subtilis Endospore-the black section in the middle  highly resistant structures  can withstand radiation, UV light, and boiling at 120oC for 15 minutes. Bacteria Survival

35 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

36 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

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

38 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

E.coli on small intestines Helpful Bacteria

40 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

41 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

42 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

43 BLUE-GREEN BACTERIA Autotrophs – 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

44 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

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

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

Leptospira interrogans - spiral shaped prokaryote (spirochete)