Introduction Flashcards
UNDER THE SAMPLING OF FIELDS AND OCCUPATIONS IN MICROBIOLOGY
This branch studies the complex web of protective substances and reactions caused by invading microbes and other harmful entities. It includes such diverse areas as blood testing, vaccination, and allergy.
Immunology
Example:
- A specialist in the CDC special pathogens unit reads a microscopic test to screen for infection that is based on an immune reaction.
UNDER THE SAMPLING OF FIELDS AND OCCUPATIONS IN MICROBIOLOGY
These branches monitor and control the spread of diseases in communities. Some of the institutions charged with this task are the U.S. Public Health Service (USPHS) and the Centers for Disease Control and Prevention (CDC). The CDC collects information and statistics on diseases from around the United States and publishes it in a newsletter, The Morbidity and Mortality Weekly Report.
Public Health Microbiology and Epidemiology
Example:
- Public health microbiologists examine mice and take samples to determine if they carry the hantavirus, one of the emerging pathogens that concerns the CDC.
UNDER THE SAMPLING OF FIELDS AND OCCUPATIONS IN MICROBIOLOGY
This branch is defined by any process that harnesses the actions of living things to arrive at a desired product, ranging from beer to stem cells. It includes industrial microbiology, which uses microbes to produce an harvest large quantities of such substances as vaccines, vitamins, drugs, and enzymes.
Biotechnology
Example:
- A biotechnology technician prepares a bioreactor for vaccine production.
UNDER THE SAMPLING OF FIELDS AND OCCUPATIONS IN MICROBIOLOGY
These interrelated fields involve deliberate alterations of the genetic makeup of organisms to create novel microbes, plants, and animals with unique behavior and physiology. This is a rapidly expanding field that often complements biotechnology.
Genetic Engineering and Recombinant DNA Technology
Example:
- A geneticist at the US Department of Agriculture examines a wheat plant that has been genetically engineered to resist a fungal pathogen.
___________ have existed on earth for about 3.5 billion years.
Bacteria-like organisms
Microorganisms have ancient origins, with bacteria-like organisms existing on Earth for approximately 3.5 billion years.
These early life forms fall into two main categories based on their cellular structure. What are these?
Prokaryotes and Eukaryotes
These are simple, single-celled organisms without a membrane-bound nucleus. Bacteria and Archaea belong to this group.
Prokaryotes (“pre-nucleus”)
These are more complex cells with a nucleus and membrane-bound organelles. Fungi, protozoa, algae, and other microorganisms fall under this category.
Eukaryotes (“true nucleus”)
Microorganisms are classified based on their microbial structure into three main groups.
What are these?
- Prokaryote
- Eukaryote
- Viruses
WHAT IS THIS?
- Microscopic, unicellular organisms
- Lack a nucleus and membrane-bound organelles
- Includes Bacteria and Archaea
Prokaryotes
WHAT IS THIS?
- Can be unicellular (microscopic) or multicellular
- Contain a true nucleus and membrane-bound organelles
- Includes Fungi, Protozoa, Algae, and Helminths
Eukaryotes
WHAT IS THIS?
- Acellular (not made of cells)
- Parasitic particles that require a host cell to reproduce
- Composed of nucleic acid (DNA or RNA) and a protein coat (capsid)
VIRUSES
Microorganisms exist in various forms, each with unique characteristics and roles in nature.
What are the “6 Types of Microbes”?
- Bacteria
- Algae
- Fungi
- Virus
- Protozoa
- Helminths
REMEMBER THE ACRONYM BAF-VPH
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- Mycobacterium tuberculosis, a rod-shaped cell (15,500x)
Bacteria
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- Thamnidium, a filamentous fungus (400x)
Fungi
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- desmids, Spirogyra filament, and diatoms (golden cells) (500x)
Algae
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- Herpes simplex, cause of cold sores (100,000x)
Virus
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- A pair of Vorticella (500x), stalked cells that feed by means of a whirling row of cilia.
Protozoa
UNDER THE 6 TYPES OF MICROBES, the given is an example of what?
- Cysts of the parasitic roundworm, Trichinella spiralis (250x) embedded in muscle.
Helminths
Microorganisms play a crucial role in Earth’s ecosystems by contributing to the flow of energy and nutrients through two key processes.
What are these?
Photosynthesis and Decomposition
Light fueled conversion of carbon dioxide to organic material.
Photosynthesis
Breakdown of dead matter and wastes into simple compounds.
Decomposition
Microorganisms have been harnessed for various beneficial applications, contributing to advancements in health, industry, and environmental protection.
What are the 3 Human Use of Microorganisms?
- Biotechnology
- Genetic Engineering
- Bioremediation
REMEMBER THE ACRONYM BGB
Production of foods, drugs, and vaccines using living organisms.
Biotechnology
Manipulating the genes of organisms to make new products.
Genetic Engineering
Using living organisms to remedy an environmental problem.
Bioremediation
Microorganisms exist in diverse environments and interact with other organisms in different ways. Their lifestyles can be categorized based on how they survive and interact with their surroundings.
What are the 2 Lifestyles of Microorganisms?
- Free-living
- Close associations
WHAT LIFESTYLE OF MICROORGANISMS IS THIS?
- The majority of microbes live independently in nature.
- They are harmless or even beneficial to the environment and humans.
Free-living Microorganisms
Example: [Additional info only!]
- Soil bacteria (Rhizobium) – Help fix nitrogen for plants.
- Algae – Produce oxygen through photosynthesis.
- Fungi (Penicillium) – Decompose organic material.
WHAT LIFESTYLE OF MICROORGANISMS IS THIS?
- Some microorganisms establish relationships with other organisms, which can be mutualistic, commensalistic, or parasitic.
Microbes with Close Associations 🤝
Examples: [Additional info only!]
- Mutualism (+/+) – Both organisms benefit.
- Commensalism (+/0) – One organism benefits, the other is unaffected.
- Parasitism (+/-) – The microorganism (parasite) lives on or inside a host, causing damage or disease.
What do you call an organism where parasites live on or in the body of another organism?
Host
Microbes that do harm and can cause disease.
Pathogens
Global Impact of Infectious Diseases 🌍
- Nearly _______ known microbes can cause diseases in humans.
2,000
Global Impact of Infectious Diseases 🌍
- _______ new infections per year worldwide.
10 Billion
Global Impact of Infectious Diseases 🌍
- _______ deaths annually due to infectious diseases.
12 million
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TOP CAUSES OF DEATH IN THE US AND WORLDWIDE
UNITED STATES
- Heart disease
- Cancer
- Stroke
- Chronic lower respiratory disease
- Unintentional injury (accidents)
- Diabetes
- Influenza and pneumonia
- Alzheimer disease
- Kidney problems
- Septicemia (bloodstream infection)
WORLDWIDE
- Heart disease
- Stroke
- Respiratory infection
- Cancer
- HIV/AIDS
- Chronic lower respiratory disease
- Diarrheal disease
- Tuberculosis
- Malaria
- Accidents
Microbiology has evolved over 300+ years, thanks to the contributions of thousands of scientists. Key discoveries have shaped our understanding of microorganisms and their impact on life.
What are the 4 Prominent discoveries in Microbiology?
- Microscopy
- Scientific method
- Development of medical microbiology
- Microbiology techniques
REMEMBER THE ACRONYM MS-DM
It is an early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc).
Spontaneous Generation
Examples:
- Flies emerging from manure.
- Mice appearing in dirty clothes and wheat.
- Maggots forming in rotting meat.
The idea that living things can arise from other living things.
Theory of Biogenesis
Who disproved spontaneous Generation and proved the Theory of Biogenesis?
Louis Pasteur
ADD. INFO:
✅ Francesco Redi (1668)
- Experiment: Placed meat in three jars:
1️⃣ Open jar → Maggots appeared.
2️⃣ Sealed jar → No maggots.
3️⃣ Gauze-covered jar →
Maggots appeared on the gauze but not on the meat.
Conclusion: Maggots come from flies, not meat itself.
✅ Louis Pasteur (1861) – The Final Proof
Swan-neck flask experiment:
- Boiled broth in a flask with a curved neck (preventing airborne microbes from entering).
- Broth remained sterile, proving that microbes come from other microbes, not “vital forces.”
Conclusion: Living things only arise from other living things → Theory of Biogenesis.
WHO IS THIS?
- Dutch linen merchant
- First to observe living microbes
- Single-lens magnified up to 300x
Antonie Van Leeuwenhoek (1632-1723)
What do you call the Approach taken by scientists to explain a certain natural phenomenon?
Scientific Method
ADD. INFO:
1. Steps of the Scientific Method 🔬
✅ Observation & Questioning – Identify a phenomenon or problem.
✅ Form a Hypothesis – A tentative explanation based on prior knowledge.
- Uses a deductive approach: “If X happens, then Y will result.”
✅ Experimentation & Data Collection – Conduct controlled tests to evaluate the hypothesis.
✅ Analysis & Interpretation – Examine results and draw conclusions.
✅ Peer Review & Replication – Results must be published and repeatable by other scientists.
2. Progression from Hypothesis to Scientific Law 📜
- Hypothesis – A testable prediction.
- Theory – A well-supported explanation based on extensive evidence and repeated testing.
- Law or Principle – A universally accepted concept with overwhelming evidence (e.g., Newton’s Laws of Motion, Law of Gravity).
A tentative explanation that can be supported or refuted.
Hypothesis
Examples: [ADD. INFO ONLY!]
- “If I water plants daily they will grow faster”.
- “Adults can more accurately guess the temperature than children can”.
- “Butterflies prefer white flowers to orange ones”.
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Under Scientific Method, after forming a hypothesis, there will be:
- A lengthy process of experimentation, analysis, and testing either supports or refutes the hypothesis.
- Results must be published and repeated by other investigators.
(If the results are inconsistent then it will be disproved. Consistency of results — conducted by different people will be known as right and true. ACCURACY)
If hypothesis is supported by a growing body of evidence and survives rigorous scrutiny, it moves to the next level of confidence — it becomes a _______.
Theory
- A well-supported explanation based on extensive evidence and repeated testing.
If evidence of a theory is so compelling that the next level of confidence is reached, it becomes a ___________.
Law or Principle
- A universally accepted concept with overwhelming evidence (e.g., Newton’s Laws of Motion, Law of Gravity).
Who are these 2 people who discovered Heat-Resistant Microbes & Endospores?
John Tyndall and Ferdinand Cohn
WHO IS THIS?
- Discovered that some microbes can survive boiling and require prolonged heating to be destroyed.
John Tyndall
WHO IS THIS?
- Identified these heat-resistant forms as bacterial endospores, which allow bacteria to survive harsh conditions.
Ferdinand Cohn
What do you call this?
- These are dormant, thick-walled structures that some bacteria produce to survive in harsh conditions. They are resistant to heat, UV radiation, chemicals, and desiccation. It can survive for long periods of time and are difficult to kill with many antimicrobial treatments.
Bacterial endospores or ENDOSPORES
It is the complete elimination of all life forms, including endospores and viruses.
Sterilization
Note: [Additional info only!]
- Why it matters: Regular boiling kills most bacteria, but endospores require more intense methods (e.g., autoclaving).
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USING THE SCIENTIFIC METHOD TO INVESTIGATE BACTERIAL ENDOSPORES
Hypothesis
- Bacterial endospores are the most resistant of all cells on earth.
Predictions
If hypothesis is true, endospores can survive extreme conditions such as:
- Temperature (boiling)
- Radiation (ultraviolet)
- Lack of water (drying)
- Chemicals (disinfectants)
Testing
- Compare the survival of endospore and non-endospore former
- Additional tests show that endospores have thick coverings and protective features and that endospores are known to survive over million of years.
Theory/Principle
- Endospores are the only cells consistently capable of surviving a wide range of destructive environmental conditions. In order to sterilize, these cells must be eliminated.
The ________ is a source of infection.
human body
UNDER THE Development of Aseptic Techniques
- Noted that mothers who gave birth at home had fewer infections than those in hospitals.
Who is this?
Dr. Oliver Wendell Holmes
NOTE:
- Why? Hospitals had higher exposure to contaminated medical practices.
UNDER THE Development of Aseptic Techniques
- Discovered that physicians who went from autopsy rooms to maternity wards without washing hands caused deadly infections.
Who is this?
Dr. Ignaz Semmelweis
NOTE:
- Solution: Handwashing with disinfectants dramatically reduced infections.
UNDER THE Development of Aseptic Techniques
- Introduced aseptic techniques to reduce microbes in medical settings and prevent wound infections.
Who is this?
Joseph Lister
Practices to do:
- Hand disinfection with chemicals before surgery.
- Use of heat to sterilize surgical tools.
For centuries, people believed that diseases were caused by sins, bad character, or poverty rather than microscopic organisms.
- The _____________ proved that many illnesses result from the growth of microbes in the body, not moral failings or social conditions.
Germ Theory of Disease
Who are the 2 Major Contributors to the Germ Theory of Disease?
Louis Pasteur and Robert Koch
WHO IS THIS?
- Conducted experiments that showed microbes cause fermentation and spoilage.
- Disproved spontaneous Generation of microorganisms.
- Developed pasteurization (a process that uses heat to kill harmful bacteria in food and beverages.)
- Demonstrated what is now known as “Germ Theory of Disease”.
Louis Pasteur (1822-1895)
WHO IS THIS?
- Provided direct proof that specific microbes cause specific diseases.
- Established Koch’s postulates.
- Identified cause (bacteria) of anthrax, TB, and cholera.
- Developed pure culture methods.
Robert Koch (1843-1910)
This is a sequence of experimental steps that verified the germ theory.
Koch’s Postulates
Note: [Additional info. only]
The Four Postulates
- Postulate 1: The suspected pathogen must be found in all cases of the disease but not in healthy individuals.
- Postulate 2: The microorganism must be isolated from the diseased host and grown in a pure culture.
- Postulate 3: When the cultured microbe is introduced into a healthy individual, it must cause the same disease.
- Postulate 4: The microorganism must be re-isolated from the newly infected host and shown to be identical to the original microbe.
It is the science of classifying, naming, and identifying living organisms.
Taxonomy
He developed the formal system of classification or Taxonomy.
Carl von Linné (Carolus Linnaeus)
What are the Three Main Areas of Taxonomy?
- Classification
- Nomenclature
- Identification
WHAT IS THIS?
- Orderly arrangement of organisms into groups.
Classification
Note:
- Organizing organisms into hierarchical groups based on similarities.
WHAT IS THIS?
- Assigning scientific names to organisms using the binomial system (Genus species).
Nomenclature
WHAT IS THIS?
- Determining and recording traits of organisms for placement into taxonomic schemes.
Identification
It is the system used to assign each microbe a two-part scientific name to ensure clarity in classification.
Binomial nomenclature (scientific)
Binomial nomenclature is the biological system of naming the organisms in which the name is composed of two terms.
What are these?
Genus and species
Note:
NAMING RULES
- Always italicized in print
- Underlined when handwritten
IN BINOMIAL NOMENCLATURE
- The first part of the name
- Always capitalized
- Groups closely related species together
- Can be abbreviated after first use (Escherichia coli → E. coli)
Genus
IN BINOMIAL NOMENCLATURE
- The second part of the name
- Always lowercase
- Refers to a specific organism within a genus
- Organisms of the same species can reproduce and share key traits
Species
WHAT IS THIS?
- The study of the natural relatedness between groups of organisms, showing their evolutionary history.
Phylogeny
WHAT IS THIS?
- The gradual change of living organisms over long periods, leading to new species.
Evolution
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Explanation of Evolutionary Principles
All new species originate from preexisting species
- This means that no species appears out of nowhere. Every living organism today evolved from an ancestor. For example, modern bacteria evolved from ancient microbes that existed billions of years ago. This is why we can trace the lineage of organisms through their genetic material.
Closely related organisms have similar features because they evolved from common ancestral forms
- Organisms that share a recent common ancestor will have similar structures, functions, or genetic sequences. For example, Escherichia coli and Salmonella are both bacteria that belong to the Enterobacteriaceae family because they evolved from a shared ancestor. Their similarities in shape and metabolism reflect their common origin.
Evolution usually progresses toward greater complexity
- Over time, simple organisms can develop more specialized structures and functions. For example, early prokaryotic cells (bacteria) evolved into more complex eukaryotic cells (with a nucleus and organelles). This allows for greater adaptability and survival in different environments.
Changes favoring survival are retained & less beneficial changes are lost
- This is the principle of natural selection. If a genetic mutation helps an organism survive (e.g., antibiotic resistance in bacteria), that trait is passed on to future generations. On the other hand, harmful or unnecessary traits tend to disappear over time because organisms with those traits are less likely to survive and reproduce.
The classification of all living organisms is divided into three domains based on genetic and structural differences.
What are the Three Domains of Life?
- Bacteria
- Archaea
- Eukarya
REMEMBER THE ACRONYM BAE
UNDER THREE DOMAINS OF LIFE
- True Bacteria
Bacteria
UNDER THREE DOMAINS OF LIFE
- Odd bacteria that live in extreme environments, high salt, heat, etc.
Archaea
UNDER THREE DOMAINS OF LIFE
- Have a nucleus and organelles.
Eukarya
All living organisms are classified based on their evolutionary relationships. The three domains of life—Bacteria, Archaea, and Eukarya—originate from a common _________, which was the first form of life on Earth.
Ancestral cell line
The ff are classified on what domain?
- Cyanobacteria
- Chlamydias Spirochetes
- Gram-positive bacteria
- Endospore producers
- Gram-negative bacteria
Domain Bacteria
The ff are classified on what domain?
- Methane producers
- Prokaryotes that live in extreme salt
- Prokaryotes that live in extreme heat
Domain Archaea
The ff are classified on what domain?
- Plantae
- Animalia
- Fungi
- Protista
Domain Eukarya
Domain Archaea (Methane producers) – Produce methane gas, found in swamps and animal intestines.
What do you call these prokaryotic organisms?
Methanogens
What do you call these prokaryotic organisms – Live in highly salty environments like the Dead Sea?
They are Extreme Salt Lovers.
Halophiles
What do you call these prokaryotic organisms – Thrive in boiling water, like hydrothermal vents.
They are Extreme Heat Lovers.
Thermophiles
