Microbio Unit 1

Vocabulary-style flashcards covering the types of microbes, history of microbiology, microbial applications, and the classification of organisms as presented in the lecture notes.

Microorganisms

Organisms that are too small to be seen with the unaided eye.

Bacteria

Unicellular prokaryotes with peptidoglycan cell walls that divide by binary fission and may use flagella for movement.

Archaea

Prokaryotes whose cell walls lack peptidoglycan (or lack a cell wall entirely) and often live in extreme environments like those of methanogens, extreme halophiles, and extreme thermophiles.

Fungi

Eukaryotes with chitin cell walls that absorb organic chemicals for energy; includes unicellular yeasts and multicellular molds or mushrooms.

Mycelia

Masses composed of filaments called hyphae found in multicellular fungi like molds.

Protozoa

Single-celled eukaryotes that lack cell walls, absorb or ingest organic chemicals, and are often motile via pseudopods, cilia, or flagella.

Algae

Eukaryotes with cellulose cell walls that use photosynthesis for energy and are widely distributed in freshwater and saltwater.

Viruses

Acellular, obligate intracellular parasites consisting of a DNA or RNA core surrounded by a protein coat, which may be enclosed in a lipid envelope.

Helminths

Multicellular animal parasites, specifically parasitic flatworms and roundworms.

Cell Theory

The theory that all living things are composed of cells, first observed by Robert Hooke in 1665.

Biogenesis

The hypothesis that living cells arise only from preexisting living cells, stated by Rudolf Virchow in 1858.

Aseptic techniques

Techniques used to prevent microbial contamination, based on the experiments of Louis Pasteur.

Germ Theory of Disease

The concept that microorganisms cause disease, first proven by Robert Koch in 1876.

Koch’s postulates

A series of experimental steps used to demonstrate that a specific microbe causes a specific disease.

Immunity

The protection from disease provided by vaccination.

Chemotherapy

The treatment of disease with chemical substances, including synthetic drugs and antibiotics.

Antibiotics

Chemicals produced by bacteria and fungi that inhibit or kill other microbes.

Microbial ecology

The study of the relationship between microorganisms and their environment.

Microbiome

The ecosystem consisting of microbes, their collective millions of genes, and the environment they live in.

Normal microbiota

The collection of microbes that are normally present on or in a healthy human being.

Bioremediation

The use of microbes to clean up pollutants from the environment.

Biotechnology

The use of microbes for practical applications, such as producing foods (vinegar, cheese) and chemicals (ethanol, acetone).

Recombinant DNA technology

A subset of biotechnology using genetically modified organisms to produce proteins, vaccines, and enzymes, or to deliver genes via gene therapy.

Binomial nomenclature

A system developed by Carolus Linnaeus in 1735 where each organism is given two names: the genus and the specific epithet.

Taxonomy

The science of classifying organisms into categories called taxa to show the degree of similarity.

Three-Domain System

A classification system developed by Carl Woese in 1990 based on rRNA sequences, comprising Bacteria, Archaea, and Eukarya.

$$70S$$

The size of ribosomes found in prokaryotic cells and eukaryotic organelles (mitochondria and chloroplasts).

$$80S$$

The size of ribosomes found in eukaryotic cells.

Five-Kingdom System

A classification system formalized by Robert Whittaker in 1969 that grouped all prokaryotes into Kingdom Monera.

Bacterial species

A population of cells with a high degree of genomic similarity.

Strain

A sub-type or genetic variant within a single bacterial species.

Viral species

A population of viruses with similar characteristics (morphology, genomes, ecological niche) that can be distinguished from other species.

What types of microbes are studied in microbiology?

Bacteria, Archea, Fungi, Protozoa, Algae and Viruses

Bacteria

Prokaryotes — unicellular, peptidoglycan cell walls, binary fission reproduction, nutrition from organic/inorganic molecules OR photosynthesis. Swim with flagella.

Protozoa

Eukaryotes, asexual or sexual reproduction, no cell walls. Motile with cilia, flagella, pseudopods. Simple celled with complex internal structures.

Archea

Prokaryotes, unicellular, no peptidoglycan or cell walls AT ALL. Extreme environments

Fungi

Eukaryotes, chitin cell walls. E absorbed from organic chemicals but cannot do photosynthesis.

Helminths

Parasitic flatworms and roundworms,

Algae

Eukaryotes — multi/unicellular, cellulose cell walls. Photosynthesis, food source for other organisms. Sexual and asexual reproduction. Do NOT require organic compounds from environment

Viruses

Acellular (are not cells), extremely small, DNA or RNA core, coat maybe enclosed in lipid envelope. Can only replicate inside living host cell. Lack metabolism or reproduction qualities — obligate intracellular parasites.

What are the major differences between bacteria and archaea?

Bacteria has cell walls with varying amounts of peptidoglycan, mainly reproducing through binary fission. Archea usually remains in extreme environments and does not contain cell walls nor peptidoglycan.

Hooke

Created cell theory, saying all living things are composed of cells. Lifes smallest structural units composed of cells

Leeuwenhoek

“Father of Microscopy,” with first microbe observation. Thought of spontaneous generation, saying life evolved from nonliving matter. “Animalcules” in magnifying levels.

Virchow

Biogenesis- Living cells are ONLY from preexisting living cells.

Pasteur

Disproved spontaneous generation, demonstrating that microorganisms are present in non-living matter and are responsible for contamination. Contamination of sterile solutions but air does NOT create microbes.

Lister

Asceptic - Carbolic acid to prevent surgical wound infections — Germ theory of disease

Koch

Bacillus Anthracis causes anthrax and produced in experimental steps. Kochs postulates demonstrates specific microbe causes specific disease

Jenner

Inoculation with cowpox made patient immune or protected against the disease

Erilich

“magic bullet'“ arsenic containing chemical to treat syphillis

Fleming

Penicillin inihibited bacterial growth and utilized as an antibiotic since 1940

Waksman

He isolated a microbe that produced an antibiotic, and he named the antibiotic tyrothricin. It cured localized staphylococcal infections in humans

Microbiome

Microbes plus their collective millions of genes and environment they live in

Microbiota

Trillions of actual bacteria, fungi, viruses in gut and skin surface

Beyond the human body, what are some other ways microbes impact our lives and society?

Use of microbes for practical aplications such as producing food and chemicals, understanding functions of diseases and other life processes, using microbes to clean up pollutants (biomediation).

Ionic Bonds

Opposite charges to form stable molecule

Covalent Bonds

Sharing one or more pairs of electrons — considered stronger and more common

Hydrogen bonds

H+ covalently bonded to O2 or N2 atom, leading to diassociation or separation into individual molecules into water.

Water characteristics

Temperature buffer, solvent, polar/ionic substances undergo disassociation to form solutes, reactant or product in many reactions, surface tenstion

Carbs

Cellular E sources, components of cell structures

Lipids

Non-polar and insoluble in H2O. Functions as E storage and structural component of plasma membrane

Fats

Glycerol and fatty acids

Phospholipids

Glycerol, 2 fatty acids, phosphate group, amphipathic

Steroids

Cholesterol and part of plasma membrane

Proteins

Amino acids remain as building blocks (20). Primary, secondary, tertiary, quaternary structures. Enzymes, transport proteins, receptor proteins

Nucleic Acid

Carry genetic information, made of DNA and RNA — made of nucleotides.

Why is ATP important?

Stores E released by some chemical reactions in high E bonds. Provides E by hydrolysis for reactions that require E

How is total magnification calculated. Define the resolving power of a light microscope. What are the best magnification and resolution which can be achieved by light microscopes? Why do you add oil to the slide when using the 100x objective.

Total magnification = objective lens X ocular lens

Resolving power - ability of the lenses to distinguish 2 points or the ability to distinguish detail or structure. (Wavelength/2NA) - numerical aperture of lens

How does immunofluorescence help identify a specific pathogen in a patient sample?

Antibodies identifies, specific for type of microbial pathogen are prepared and tagged with a fluorochrome. Fluorescent antibodies applied to microscope slide bearing specimen that may contain the pathogenic microbe; will adhere if antibodies are present.

Explain what kinds of cellular structures (internal vs. surface) each EM is best used to visualize.

Used for images too small for light microscopes such as internal cellular structures and viruses

What is the value of Gram Stain in medical microbiology?

Can help identify unknown bacterium can provide valuable treatment information. Most consistent when used on young, actively, growing bacteria.

Why do bacterial cells need to be stained for best viewing even when they are magnified under a light microscope? Define acidic and basic dyes. Why does a simple stain commonly use a basic dye?

Basic dyes - Color is in the cation

Acidic dyes - Color is in the anion

Most bacterial cells need to be stained because they appear almost colorless. Basic dyes are most commonly used because acidic dyes are not attracted to most types of bacteria, staining the background instead since and the dye’s negative ions are repelled by the negatively charged bacterial surface.

Briefly explain why each of the following is used: simple stain, Gram stain, acid-fast stain, capsule stain, endospore stain, flagella stain.

Simple stain - aqueous or alcohol solution of a single basic dye, highlight entire microorganism to make cellular shapes visible.

Acid-fast stain-

Capsule stain

En