Microbiology Exam 1

7 groups of microorganisms

• Cellular

  • Prokaryotes

    • Bacteria

    • Archaea

  • Eukaryotes

    • Fungus

    • Protozoan

    • Helminth (able to cause human disease)

• Acellular

  • Virus

  • Prion (misfolded proteins acting as infectious agent by forcing normal proteins in brain to change into abnormal shape)

Lactobacillus spp. and Penicillium spp.

used in cheese making

Bacillus thuringiensis

pesticide

• break down the digestive tract

Pseudomonas fluorescens

recombinant microbe

• created in lab by combining genetic material

• help destroy pests

Pseudomonas spp

bioremediatory

• use crode oil for food and energy

• clean up oil spills in the ocean

Plasmodium

cause malaria

Microbiology

the specialized area of biology that deals with organisms too small to be seen with the naked eye

Bioremediation

Intro of microbes into the environment to restore stability or to clean up toxic pollutants

Pathogen

• less than 1%

• an agent that causes disease

Biotechnology

manipulation of microorganisms to make products in an industrial setting

viruses

small amount of hereditary material wrapped in protein covering

Prions

small intricately folded

Spontaneous generation

• abiogenesis

• living things arose from “vital forces” present in nonliving or decomposing matter

• life comes from nothing

Germ Theory of disease

theory that microorganisms cause disease

Timeline of big names/accomplishments

• Hippocrates (400 BCE)

  • associated symptoms with illness

  • established ethical standards for practice (HIPPA)

• Ibn Sina (Avicenna) (1000 CE)

  • described contagious disease spread + methods for quarantine

  • recognition of infectious diseases (smallpox, STI, leprosy)

• Black Death

  • swelling of lymph nodes (buboes)

  • yersinia pestis (bacteria), rats reservoirs, vectored by fleas

• Francesco Radi (1668)

  • tested spontaneous generation and disproved it

• Robert Hooke (1660)

  • early compound microscopes to capture images

• Anton van Leeunwenhoek (1670s)

  • first to observe independent microorganisms

• Edward Jenner (1796)

  • used fluid from cowpox sore of a milkmaid to inoculate a child, innoculated child w smallpox and found resistant = vaccine

• Oliver Wendel Homes Sr (1843)

  • argues for cleaning instruments, burning contaminated clothing, hand washing

• Ignaz Semmelweis (1847)

  • required medical staff to scrub hands w chlorinated lime solution

• Florence Nightingale (1854)

  • nursing, medical statistics, documentation of mortality & medical care, improved sanitary conditions

• John Snow (1854)

  • cholera outbreak: traced source to water pumps

• Louis Pasteur (1859)

  • disproves spontaneous generation

  • rabies vaccine, chicken colera vaccine, showed microbes are responsible for fermentation

• Joseph Lister (1860)

  • antiseptic surgery ( use of chemicals to destroy germs already present), chemical disinfection

• Robert Koch (1875)

  • verified Germ theory, etiology

  • organism must be present in every case, but absent in healthy individual

• Fanny Hesse (1881)

  • suggested agar for experiments

• Richard Petri (1887)

  • dish with lid, turn upside down to min. contamination and disturbance by condensation

• Hans Christian Gram (1884 )

  • developed staining technique = gram stain

• Dmitiri Ivanovsky (1892)

  • miniscule infectious agent, tobacco plant virus

• Ernest Ruska and Max Knoll (1931 )

  • invented electron microscope

• Helmut Ruska (1938)

  • publishes first photographs of poxvirus

• Alexander Fleming

  • penicillium fungus made an antibiotic that killed staphylococcus aureus

• Henrietta Lacks

  • biopsy of her cervical cancer cells, taken for research without consent

• Eradiation of smallpox

  • 1850 - 1900 = vaccination widespread in Europe and North America

  • 1950 - 1970 = mass produced vaccines distributed globally by WHO

Etiology

study of the causes or origins

Variolation

a method of inoculation involving direct contact with diseased tissue or discharge to build immunity

Vaccination

inoculation with a safe, related germ (cowpox) or a weakened version (rabies)

Koch’s postulates

• microorganism must be present in every case of disease but absent in healthy individuals

• must appear in healthy host after inocculation

Yersinia pestis (bacteria) - Bubonic Plague

• vectored by fleas

• wild rodent reservoirs

• hosts: humans, cats, prairie dogs

Prokaryotes: Bacteria (Cell structure) IN ALL

• External

  • none

• Boundary

  • cytoplasmic cell membrane

• Internal

  • chromosome or nucleoid

  • Ribosomes

  • Cytoplasm

Prokaryotes: Bacteria (Cell structure) IN SOME

• External

  • Appendages (Fimbrae, pilus,

  • Surface Layers (S layer, capsule or “glycocalyx”, flagellum, nanowories/nanotubules)

• Boundary

  • Outer Membrane

  • Cell Wall

• Internal

  • Microcompartments

  • Plasmid

  • Endospore

  • Intracellular Membrane

Coccus

Prokaryotes: Bacteria Shape: spheres, oval, bean-shaped

Rod

(bacillus)

• Prokaryotes: Bacteria Shape

• round-ended, drumstick-shaped

Curved

• Prokaryotes: Bacteria Shape

• spirilium

Pleomorphism

• variations in size and shape among cells of same species due to nutritional or slight genetic differences

Diplococci

• Groupings for cocci

• pairs

Tetrads

• Groupings for cocci

• groups of four

Staphylococci & micrococci

• Groupings for cocci

• irregular clusters

streptococci

• Groupings for cocci

• chains of a few to hundreds of cells

Sarcina

• Groupings for cocci

• cubical packets of 8, 16, or more cells

Diplobacilli

• Groupings for rods (bacillus)

• pairs of cells with their ends attached

streptobacilli

chains of cells

• Groupings for rods (bacillus)

palisades

cells of chain remain partially attached and folded back, creating a side-by-side row of cells

flagella and axial filaments

appendages for motility

fimbrae, pili and nanowories

for attachment points or channels

Polar arrangement

flagella attached at one or both ends of the cell

Monotrichous

single flagellum

lophotrichous

small bunches or tufts of flagella

amphitrichous

flagella at both poles

chemotaxis

movement in response to chemical signals

positive chemotaxis

movement toward a favorable chemical signal

negative chemotaxis

movement away from a repellent or potentially harmful chemical signal

phototaxis

movement toward light

run

counterclockwise movement of the flagella

tumble

reverses direction to stop and change course

axial filament (periplasic flagellum)

a type of internal flagellum found in spirochetes, reponsible for locomotion

• twisting or flexion motion

fimbria

provide adhesion, not locomotion

• stick to each other

pilus

provide adhesion, not locomotion

• found ONLY in gram-negative bacteria

• used in conjugation, the patial transfer of plsmid DNA from one cell to another

nanowires

provide adhesion of two cells creating a channel

• used as channels to transfer

s layer

• thousands of copies of a single protein linked together

• protection from environemtn

• only produced in hostile environments

glycocalyces

• repeating polysaccharide units

• slime layer (protects from loss of water and nutrients)

• capsule (glycocalyx)

hami

• surface structures

• hook-like, anchor to surfaces

cannulae

• tube-like, connect multiple cells together

extremophiles

• heat, salt, acid, pH, pressure, atmosphere

• psychrophilic: cold loving

• hyperthermophilic: heat loving (salt and acid tolerant)

• halophilic = salt loving

• use red pigment to synthesize ATP in the presence of light

methanogens

• methane producers

• convert CO2 and H2 into methane gas

cell envelope

• outer membrane

• cell wall

• cytoplasmic membrane

• act as a single protective unit

gram - positive

• THICK cell wall composed of peptidoglycan

• stains purple

gram - negative

• outer membrane

• THIN cell wall composed of peptidoglycan

  • gives bacteria greater flexibility and sensitivity to lysis

• inner cytoplasmic membrane

• stains pink

peptidoglycan

provides strong but flexible support framework

teichoic and lipoteichoic acid

• cell maintenance and division

• negative charge to cell surface

• can serve as attachment point for bacteriophages

bacteria - cytoplasmic membrane structure

• 30-40% phospholipids

• 60-70% proteins

• mycoplasmas contain high amounts of sterols

• archea contain unique branched hydrocarbons rather than fatty acids

bacteria - functions of the cytoplasmic membrane

• energy reaction

• nutrient processing

• synthesis

• regulate transport

  • passage of nutrients into the cell

  • discharge of wastes out of the cell

secretion

discharge of metabolic products into the extracurricular environment

gram-negative outer membrane

• porin proteins: only allow relatively small molecules to penetrate

• act as a defense against certain antibiotics

• resistant to antimicrobial chemicals

• more difficult to inhibit or kill than gram-positive bacteria

endotoxin

stimulates fever and shock reactions when released

cytoskeleton

• long polymers of proteins

• contribute to cell shape

• binary fission: asexual reproduction of prokaryotes

• potential target for antibiotic development

svedberg (S) units

measurement of relative size of cell parts through sedimentation during centrifugation

plasmids

nonessential pieces of DNA

confer protective traits

inclusion bodies

• storage sites for nutrients during periods of abundance

endospores

• withstand hostile conditions and facilitate survival

endospores life cycle

• vegetative: normal, metabolically active

• endospore: inert, resting

sporulation

endospore formation induced by environmental conditions

stimuli for endospore formation

depletion of nutrients, especially carbon and nitrogen

diseases related to persistance and resistance of bacterial endospores

• Antrax (bacillus anthracis)

• Tetanus, lockjaw (Clostridium tetani)

• Gas Gangrene (C. perfringens)

• Botulism (C. botulinum)

endosymbiosis

relationship in which a microorganism resides within a host cell and provides a benefit to the host

Eukaryotes - features of the cell (Found in ALL)

Boundary

• cytoplasmic membrane

Internal

• cytoplasm

• cytoskeleton

• nucleus

• mitochondria

• endoplasmic reticulum

• golgi apparatus

• cellular vesicles

Eukaryotes - features of the cell (Found in some)

External

• locomotor appendages

• glycocalyx

  • most-single celled euks.

Boundary

• cell wall

Internal

• chloroplasts

glycocalyx

extracellular matrix

• composed of polysaccharides

rigid

provide structural support and shape

fungi cell wall

chitin or cellulose

algae cell wall

cellulose

bacteria

peptidoglycan mesh (& outer membrane for gram negative)

cytoskeleton types

• actin filaments

• intermediate filaments

• microtubules

Nature’s Assembly Line

• nucleus

• ER

• Golgi Apparatus

lysosomes

breaking stuff down

vacuoles

storage

cristae

folds on the inner membrane that hold the enzymes

protist

any eukaryotic unicellular or colonial organism that lacks true tissue

plankton

photosynthetic plankton produce 70% of earth’s oxygen

algae

photosynthetic protists

eutrophication

• nutrient influx

  • excess fertilizers, sewage

• algal bloom

• oxygen depletion

cyanobacteria

• blue-green algae

diatoms & dinoflagellates

• red tide

• medical threat from algae is through ingesting toxins

oral groove

channel on the side of the cell where cilia sweep bacteria and algae in

buccal cavity

from the oral groove, food moves down a tube

cytostome

where the gullet ends, food enters the interior of the cell, and a food vacuole digests it

heterotrophic

require food in complex organic form

parasitic species

live on fluids of the host

• plasma

• digestive juices

• tissues

pseudopds “false feet”

amoeboid motion, serves as feeding structure