Microbiology Chapter 1

The Scope of Microbiology

Microbiology: the specialized area of biology that deals with organisms too

Microorganisms or ________

Germs, viruses, ______, or “____”

Only a _____ minority cause ____ to other living beings

small to be seen with the naked eye

microbes

agents, bugs

small, harm

Major Groups of Microorganisms

Cellular microorganisms:

• Bacteria

• _______

• Fungi

• Protozoa

• _________—not technically a microorganism but able to

cause human infection

Archaea, Helminths

Noncellular microorganisms:

• Viruses

• ______

Prions

Microbes

Microbes are ____ and difficult to study

• Reproduce _______, large populations can be grown in the laboratory

• Cannot be seen directly, must be analyzed through indirect methods in addition to using microscopes

easy, rapidly

Microbiologists

Microbiologists study:

• ____ structure and function

• Growth and physiology

• ________

• ________ and evolutionary history

• Interactions with the living and nonliving environment

Cell, Genetics, Taxonomy

Branches of Microbiology

Medical Microbiology:

Deals with ________ that cause diseases in humans and _______

microbes, animals

Branches of Microbiology

Public Health Microbiology and Epidemiology:

• Monitor and control the spread of diseases in ___________

• USPHS, ___, and WHO

communities, CDC

Branches of Microbiology

Immunology:

• Complex web of __________ substances and cells produced in response to ________

• Includes vaccination, blood testing, and _______

protective, infection, allergy

Branches of Microbiology

Industrial Microbiology:

• Safeguards our food and water

• _____________

• Microbes used to create amino acids, ____, _____, enzymes, and vitamins

Biotechnology, beer, drugs

Branches of Microbiology

Agricultural Microbiology:

• Relationships between microbes and farm animals and _____

• _____ specialists and animal specialists

crops, Plant

Branches of Microbiology

Environmental Microbiology:

• Effect of microbes on the earth’s diverse ________

• Aquatic, soil, geomicrobiology, and __________

habitats, astrobiology

The Impact of Microbes on Earth

• ________ have shaped the development of the earth’s _______ and the evolution of other life forms for billions of years

• Soon after the earth was formed, the first ancient cells formed and from them, bacteria and archaea developed

• __________ appeared more than a billion years later

Microbes, habitats, Eukaryotes

Eukarya Versus Bacteria and Archaea

Cells with a _______ are classified as eukaryotes

• “______-” means true nucleus

• Cells without a nucleus are classified as _________

• ________ and archaea have no true nucleus

nucleus, Eukary, akaryotes, Bacteria

Bacteria Are Ubiquitous

Bacteria are ubiquitous, meaning they can be found nearly __________

They are found:

• Deep in the earth’s crust

• ____ ___ ____

• Oceans

• Inside the bodies of plants and animals

everywhere, Polar ice caps

Microbial Involvement in Shaping Our Planet

Microbes are deeply involved in the flow of _____ and ____ through the earth’s ecosystems

Bacteria invented ______________

• __________ photosynthesis and the later evolution of oxygenic photosynthesis

• The production of oxygen by microbes allowed _______ diversification

energy, food, photosynthesis, Anoxygenic, species

Photosynthetic Microorganisms

Photosynthetic microorganisms:

• Contribute the majority of the oxygen to the atmosphere

• Accomplished by bacteria and _____, which account for more than __% of the earth’s

photosynthesis

algae, 70%

Decomposition

Decomposition:

• _________ of dead matter and wastes

• Accomplished by bacteria and _____

Breakdown, fungi

Microbes Drives Structure and Content of Soil, Water, and Atmosphere

Microbes are the main forces that drive the structure and content of ___, water, and atmosphere

• ___ production by microbes

• Microbes living within the earth’s _____

• Bacteria and fungi living in complex associations with plants and animals

soil, Gas, crust

Human Use of Microorganisms

Humans have been using microorganisms for thousands of years to improve life and even shape civilizations

• _____ for production of bread, wine, and beer

• Other fungi used for ______ production

• Moldy bread used in Egypt to treat wounds

Yeast, cheese

Human Use of Microorganisms

Biotechnology:

• Manipulation of……

• microorganisms to make products in an industrial setting

Human Use of Microorganisms

Recombinant DNA technology: 

• Manipulates the genetics of microbes, plants, ……

• and animals to create new products and genetically modified organisms (GMOs)

Human Use of Microorganisms

Bioremediation: 

• Introduction of microbes into the environment to…..

• restore stability or to clean up toxic pollutants

Pathogens

Pathogen: any agent such as a virus, bacterium,……

• Nearly 2,000 different microbes can cause disease

fungus, protozoan, or helminth that causes disease

Malaria

• Kills about ___,___ every year

• Transmitted by __________

• Prevention of infection is through the use of bed nets, which although inexpensive, are too expensive for poor families

450,000, mosquitoes

Infectious Diseases

New (emerging) diseases as well as older (reemerging) diseases are increasing

• SARS-CoV-2, Ebola, AIDS,……

Polio, leprosy, and parasitic worm diseases have largely been eradicated

• hepatitis C, and viral encephalitis

Weakened Immune Systems and Drug Resistance

• An increasing number of patients with weakened immune systems are…..

• Drug-resistant microbes also contribute to the….

• subject to infections by common microbes not pathogenic to healthy people

• increase in infectious disease

General Characteristics of Microorganisms

Three basic cell lines appeared during evolutionary history differing in complexity, contents, and function.

• _______, Eukarya, and _______

The majority of microorganisms are single-celled:

• All bacteria and archaea and some __________

Some microorganisms are multicellular:

• ________ and some fungi

• Archaea, Bacteria

• eukaryotes

• Helminths

Cellular Organization

Bacterial and Archaeal cells:

• About __x smaller than eukaryotic cells

• Lack __________: small, double-membrane-bound structures that perform specific functions

Eukaryotic cells:

• Contain organelles like the nucleus, ___________, and chloroplasts

10, organelles, mitochondria

Acellular Microorganisms

_______:

• Composed of a small amount of hereditary material (either DNA or RNA but never both) wrapped up in……

Prions:

• Small proteins folded in intricate ways which sometimes…..

Viruses, a protein covering that is sometimes enveloped by a protein-containing lipid membrane, behave like microorganisms and are transmitted from one human to another

Six Types of Microorganisms

1.Helminth

2.Fungus

3.Protozoan

4….

5….

6….

Bacteria, Virus, Prion

Early Ideas About Disease Transmission

• Certain foods spoiled, became inedible, or caused illness

• Black plague and smallpox are caused by some kind of transmissible matter

• Belief in spontaneous generation

Development of the Microscope

Robert Hooke: 

• First observations of….

Antonie van Leeuwenhoek:

• Made a crude….

• Made drawings of what he called “animalcules” in rainwater and scraped from his teeth

• microbes in the 1600s

• microscope to examine threads in fabrics

Modern Microscopes

Modern microscopes:

• More refined lenses, a condenser, finer…..

• Student microscopes are not greatly different in structure and function than early microscopes

• focusing devices, and built-in light sources

The Century of Biology

• 1980s: The invention of the PCR technique

• 2000s: The importance of small RNAs

• 2010s and beyond:

• Genetic identification of the human microbiome

• 2013: CRISPR technology

• Science is an ever-evolving collection of new information

The Development of Medical Microbiology

Early experiments showed that microbes are everywhere:

• Air and dust are full of them

• The entire surface of the earth and….

• its waters, and all objects are inhabited by them

The Discovery of Spores and Sterilization

…. …….:

• Found that microbes in the dust and air have …..

Later the discovery and detailed description of heat-resistant bacterial endospores clarified the heat resistance of microbes

Sterile: completely free of ……

John Tyndall, high heat resistance, all life forms including spores and virus particles

Development of Aseptic Techniques

Robert Koch:

• Linked a specific microorganism with….

Dr. Oliver Wendell Holmes:

• Observed that mothers who gave birth at home experienced ……

Dr. Ignaz Semmelweis:

• Showed that women became infected in the maternity ward after examinations by physicians who had been working in the autopsy rooms ……

• a specific disease

• fewer infections than mothers who gave birth in the hospital

• without washing their hands

Development of Aseptic Techniques

Joseph Lister:

• First to utilize ……..

• Techniques became the foundation for modern microbial control still in use today

• handwashing and misting operating rooms with antiseptic chemicals

Discovery of Pathogens and the Germ Theory of Disease

Pasteur: 

• Invented ……

• Showed that human diseases could arise from infection

Robert Koch: 

• Established a series of ……

• pasteurization

• proofs that verified the germ theory of disease