Microbiology Final Review

Prokaryote

A cell without a nucleus (before nucleus)

Eukaryote

A cell with a nucleus

Microbe

Microscopic organism

Pathogen

Disease causing agent

Microscopy

Use of a microscope to observe organisms

Nomenclature used

Naming and grouping organisms

Etiology

Cause of a disease

Bacteremia

Presence of bacteria in the blood

Pathology

Study of disease

Symptoms

Conditions that together tell a doctor what is wrong

Infection

Invasion of the body by pathogenic microorganisms

Pathogenesis

Development of disease

Microbiota

Microbes that are normally present in and on the human body; usually beneficial

Transient microbiota

Temporary microbiota (present for some time then disappear)

Opportunistic pathogens

Can cause disease if outside of their normal habitat

Photo-heterotroph

Organism that obtains energy from sunlight and carbon from organic sources.

Photoautotroph

Organism that uses energy from sunlight to convert carbon dioxide and water to carbon compounds

Chemoautotroph

Organism that makes organic carbon molecules from carbon dioxide using energy from chemical reactions

Chemo-heterotroph

Organism that must take in organic molecules for both energy and carbon

Microbial antagonism

Competition between microbes

Competitive exclusion

Strong competition can lead to local elimination of one of the species

Capsule

Covers the cell wall in prokaryotes

Biofilm

A surface-coating colony of prokaryotes that engage in metabolic cooperation

Contagious disease

An easily spreadable disease

Non-contagious disease

A disease that does not spread easily

Communicable disease

Any disease that spreads from a host to another (ex. HIV)

Non-communicable disease

A disease that is not spread from one person to another (ex. diabetes)

Pili

Appendages that allow bacteria to attach to each other and to transfer DNA (hair)

Conjugation

The direct transfer of DNA between two cells that are temporarily joined

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Flagella

Whip-like tails found in organisms to aid in movement

Incidence

The number of people in a population who develop a disease during a particular time period (new cases in a single year)

Prevalence

The number of people in a population that develop a disease at a *specified* time (ex. 1986-2015)

Acute disease

A disease that develops rapidly but only lasts a short time

Latent period

Time between exposure to a disease and appearance of symptoms

Pandemic disease

An epidemic disease that occurs worldwide

Chronic disease

A disease that develops more slowly (less severe and recurs for long periods)

Sporadic disease

A disease that occurs occassionally

Gram-positive bacteria

Bacteria that have a thick peptidoglycan cell wall

Gram-negative bacteria

Bacteria that have a thin peptidoglycan cell wall

Peptidoglycan

Cell wall made of a sugar polymer and polypeptide

Glucose

A simple sugar that is an important source of energy (C6H12O6)

Glycogen

Storage form of glucose

Starch

Storage polysaccharide of plants

Cellulose

Carbohydrate component of plant cell walls

Permeable

Penetrable; porous; allowing liquids or gas to pass through

Impermeable

Impassable, not allowing passage through (such as by a liquid)

Selectively permeable

Some substances can pass across them and others cannot

Generalized infection (systemic)

Microorganisms are spread throughout the body by blood or lymph fluid

Localized infection

Infection of a small area of the body

Nucleoid region

The region in a prokaryotic cell consisting of a concentrated mass of DNA

Zoonosis

Diseases from wild or domesticated animals that can be transmitted to humans

Fomite

Object that transmits the infection

Direct contact

Person to person contact (touching, kissing, and sexual intercourse)

Carrier

A person that harbors pathogens and transmits them without showing any signs of illness

Vehicle transmission

Transmission by water, food, air, or body fluids

Biological transmission

Transmission from an infected person, to a vector, then to another host

Endospore

A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions

Inclusions

Chemical substances such as stored nutrients or cell products

Theory of Endosymbiosis

Mitochondria and chloroplasts used to be free-living organisms

Germ Theory of Disease

Many diseases are caused by microbes

Bacilli

Rod shaped bacteria

Cocci

Sphere shaped bacteria

Diplococci

Spherical bacteria that grow in pairs.

Streptococci

Bacteria that form a chain

Spirillium

Spiral shaped bacteria

Bacterial tetrad

Group of four bacteria

Vibrios

Curved rods

Staphylococci

Grape-like clusters (spherical)

Pleomorphic

Having many shapes

Monomorphic

Having a single shape

Robert Hooke

Discovered cells; introduced cell theory

Charles Darwin

Founder of the theory of evolution

Carolus Linnaeus

Binomial nomenclature

Anton Von Leuwonhook

Saw "animacules" and made drawings of them

Robert Koch

Supported germ theory of disease; first identified pathogens

Fracesco Redi

Spontaneous generation

Rudolf Virchow

Challenged spontaneous generation with the theory of biogenesis

Lazzaro Spallanzani

Showed that fluids heated after being sealed in a flask would not have microbial growth

Louis Pasteur

Demonstrated that microorganisms are present in the air and can contaminate sterile solutions, but the air does not create microbes

Alexander Fleming

Discovered penicillin

Joseph Lister

Supported germ theory of disease; treated surgical wounds with phenol, which reduced infection

Edward Jenner

Developed smallpox vaccine

Phase contrast microscope

Uses direct and reflected light rays together to form an image; greater detailed images

Confocal microscope

Specimen is stained with a fluorescent dye and illuminated with short-wavelength light; 2D and 3D images can be made

Darkfield microscope

Shows a silhouette of an organism against a dark background (for tiny organisms)

Compound microscope

Microscope with two lenses

Electron microscope

Uses beams of electrons; electromagnets control focus, magnification, and illumination

Transmission electron microscope

Used to see thin sections of an organism

Scanning acoustic microscope

3D views of the surfaces of the *whole* microorganism

Scanned probe microscope

Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) produce 3D images of the *surface* of a molecule

Atrichous flagella

No flagella

Monotrichous flagella

Single flagellum

Polar flagella

Flagella attached at one or both ends of the cell

Peritrichous flagella

Flagella that cover the entire surface of the cell

Lophotrichous flagella

Multiple flagella on either end

Simple stain

Use of a single basic dye

Gram stain

A staining method that distinguishes between two different kinds of bacterial cell walls

Smear

A thin film of a solution of microbes on a slide

Fixation (attachment)

Using heat to secure the microorganism to the slide