intro to micro notes

The Biology Spot:

The Microbiology Classroom

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AN INTRODUCTION TO MICROBES

1) What is the oldest form of life?

BACTERIA

-age of the earth: around 4.6 billion years old

-fossilized bacteria found in rocks: 3.8 billion years old

2) What is the most abundant and diverse form of life and why?

BACTERIA

-distribution: everywhere ( 1 billion per gram of soil, 1/3 of human feces, etc.)

-most are similar in appearance and structure

-most genetically diverse: simplicity allows for "fast evolution"

-most metabolically diverse: can eat almost anything ( most prefer organic foods like us; but some prefer inorganic foods ( petroleum, cyanide, etc.)

-most diverse in habitat: able to exploit inanimate and animate environments

(volcanoes to your intestines to your desk)

-fairly new study to science: only 1500 species identified (1%)

3) What are the 4 main categories of living microbes?

1) BACTERIA

2) FUNGI

3) PROTISTA

4) ALGAE

4) What 2 categories of microbes border between living and nonliving?

1) VIRUSES

2) PRIONS

5) What are 4 major roles microbes play in nature?

1) DECOMPOSERS:

-most feed on dead material to recycle vital nutrients and minerals

2) PHOTOSYNTHESIZERS:

-more oxygen produced from cyanobacteria and algae than plants

3) SYMBIOTES:

-live inside host to aid in metabolism (the cellulose diet of a cow is broken down really by bacteria not its intestines)

4) PARASITES:

-1-5% are pathogenic (disease causing)

-examples: bubonic plague, tuberculosis, pneumonia, cholera, whooping cough, etc.

6) What are 4 major commercial applications of microbes?

1) FOOD AND DRINK

-bacteria used in the production of most breads, dairy products and alcoholic beverages

Examples:

breads: sourdough ( Lactobacillus sanfransisco)

dairy: swiss cheese holes due to the gas production of a bacteria

alcoholic beverages: Zymomonas bacteria in a Maguey cactus undergo fermentation to make cactus beer or tequila

2) HOUSEHOLD PRODUCTS

-most cleaning agents used in the house borrow bacterial enzymes (detergents, drain cleaners, etc.)

-beauty products (acetone)

-insecticides

3) MEDICINE

-most antibiotics are made from bacteria and fungi found in the soil

-vaccines made from altered versions of the pathogenic bacteria

4) RESEARCH AND BIOTECHNOLOGY

-mass reproduction of microbes and single chromosome makes them the "perfect guinea pig" for research

-genes can be inserted into a bacteria to mass produce a specific compound: insulin, human growth factor, and interferons ( group of proteins naturally produced believed to "interfere" with viral growth)

-PCR (polymerase chain reaction): a widely used technique to mass produce millions of the same piece of genetic material uses an enzyme from a bacteria found in the hot springs ( Thermus aquaticus)

7) Where do microbes get their names?

sources of names:

1) appearance: shape and arrangement

3 general shapes:

1) circular: coccus: Micrococcus luteus

2) rod-like: bacillus: Bacillus megatarium

3) spiral: spirillium: Borrelia burgdorferi ( Lyme's disease)

Arrangement

1) chains: Streptococcus

2) clustered: Staphlyococcus

2) scientist who discovered the microbe: Escherichia coli named after Theodor Escherich

3) its habitat: Escherichia coli "coli" name after the colon in which it inhabits

8) What are 5 criteria you can use to classify a microbe in our class?

1) SHAPE

2) ARRANGEMENT

3) GRAM STAIN: type of cell wall is colored and viewed under microscope

4) MOTILE

5) EATING HABITS: types of agar it will grow on

9) How do we classify microbes?

-based on old binomial classification system of Linneus: Genus + species

** Latin-based

** classified mainly be appearance

** 7 category system: Kingdom, Phylum, Class, Order, Family, Genus, and Species

-classification systems are changing to show genetic and evolutionary relationships

** 8^th category added in the 1980s from ribosomal RNA evidence: DOMAIN

** Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species

3 DOMAINS OF LIFE

1) Archaea: Extreme bacteria in cold, hot, acidic or salty environments

2) Bacteria: Bacteria in any other environment

3) Eukarya: Kingdom Fungi, Kingdom Protista, Kingdom Plantae, Kingdom Animalia

2 DIFFERENT CELL ARCHITECTURES OF MICROBES

PROKARYOTE	EUKARYOTE

-includes 2 domains (Archaea & bacteria)	-includes Eukarya domain
-genetic material unprotected -genetic material coiled up in one circular chromosome	-genetic material protected by a membrane NUCLEUS -multiple chromosomes
-all chemical reactions occur in cell fluid	-most chemical reactions occur in specialized compartments (ORGANELLES)
-extremely small ( < 1 micrometer)	-varied sizes ( 5 um to 2 meters)

Introduction to Microbes Discussion Review

1) Comparisons: Find the similarities and differences among the 3 domains of life.

Table 2. Phenotypic properties of Bacteria, Archaea and Eukarya.

PROPERTY	EUKARYA DOMAIN	BACTERIA DOMAIN	ARCHAEA DOMAIN
Cell organization	Eukaryotic	Prokaryotic	Prokaryotic
Nuclear membrane	Present	Absent	Absent
Number of chromosome	1+	1	1
Chromosome shape	Linear: propeller like	Circular	Circular
Cell wall	Absent	Present: Protein-sugar combo (peptidoglycan)	Some do and some don't -no peptidoglycan
Amino acid that starts protein production	Methionine	N-formyl methionine	Methionine
Protein production inhibited by the antibiotic, streptomycin	No	Yes	No
Protein production inhibited by diptheria toxin	Yes	No	Yes

a) What are two ways Archaea and Bacteria are similar?

b) What are two ways Archaea and Eukarya are similar?

c) Are Archeabacteria more closely related to Bacteria or Eukarya? Explain.

2) Is this a photograph of a prokaryote or a eukaryote? Explain.

3) Write 5 statements that sum up our discussion "Introduction to Microbes"

4) Write down all the new words introduced in our discussion with a brief description.