Module 1 - Chps. 1, 3, 4, 5, 7

Bacteria

• Prokaryotes

• Single-celled microorganisms

• About 10x smaller than eukaryotic cells

• Lack membrane-bound organelles and nucleus

• Most bacteria have cell walls that contain peptidoglycan

• Some can be beneficial, some pathogenic

Archaea

• Prokaryotes

• Single-celled microorganisms

• Lack organelles

• Archaeal cell walls do not contain peptidoglycan

• Often found in extreme environments (I.e., hot springs, ocean floor)

• Not pathogenic to humans

Fungi

• Eukaryotic

• Can be unicellular or multicellular

• Include macroscopic fungi (mushrooms, puff balls) and microscopic fungi (yeast, molds)

• Do not undergo photosynthesis

• Cell walls are usually made out of chitin

• involved in decomposition

Protists

• Eukaryotic

• Include algae and protozoa

• heterotrophic, autotrophic

• can exhibit plant-like or animal-like characteristics

• unicellular or multicellular

Algae

• Plant-like organisms - includes plankton, seaweed, and kelp

• Can be unicellular or multicellular

• Undergo photosynthesis to produce energy

• Eukaryote

• Cell wall and chloroplast

• Green, red, brown

• unicellular species can be independent cells, filamentous chains, or colonia

• sexual or asexual reproduction

Autotroph

Organism that converts inorganic to organic molecules for nutrition. This includes chemosynthesizers and photosynthesizers.

Cilia

Short, hair-like protein extensions on a cell’s surface used for locomotion or feeding currents.

Contractile vacuole

Structure that expels excess liquid to maintain salt and water balance (osmoregulation). Usually appears as a large, hollow circle within the cell.

Daughter colony

Colony formed by asexual reproduction (mitosis) within the parent colony of Volvox by reproductive cells. The daughter colony is released by the parent colony once it has developed.

Dichotomus key

Tool that uses characteristics to identify organisms. This is done by answering a series of questions with two answer choices to narrow down the identity of the organism

Flagella

Long, whip-like protein extensions on a cell’s surface used for locomotion.

NOT USED FOR FEEDING

Food vacuole

Digestive organelle. Usually appears as a small, hollow circle within the cell.

Protozoa

• Eukaryotic, single-celled organisms AND/OR unicellular

• Undergo locomotion (movement) using pseudopods, cilia, and/or flagella

• Some are pathogenic to humans

• Asexual or sexual reproduction

• obtain nutrients by engulfing food particles

• Heterotrophic protists that can be free-living or parasitic.

• NO CELL WALL

Viruses

• Non-living, acellular microorganisms

• Require a host cell to reproduce

• Contain nucleic acid core (DNA or RNA) surrounded by a protein coat

• Most are too small to be seen using standard light microscope

Prions

• Acellular, misfolded proteins

• Parasitic worms

• Also known as proteinaceous infectious particles

• Can misfold normal variants of the same protein

• Do not contain a cell wall or membrane-bound organelles

• Associated with neurodegenerative disorders in animals and humans (spongiform encephalopathies)

Helminths

• Multicellular, parasitic worms

• Includes tapeworms, roundworms, and flukes

• Technically not considered microorganisms; however, eggs and larvae are microscopic

Prokaryotic cells

• Unicellular (single celled)

• NO NUCLEUS

• Typically have a single, circular chromosome located in a nucleoid

• NO MEMBRANE-BOUND ORGANELLES

• Smaller than eukaryotic cells

• Reproduce by binary fission

• Organisms that can be bacteria and archae

Eukaryotic cells

• Protists, plants, animals, fungi

• Unicellular or multicellular

• Larger and more complex cells

• Have a nucleus surrounded by a complex nuclear membrane

• Nucleus contains multiple chromosomes

• Contains membrane bound organelles such as mitochondria, endoplasmic reticulum, and Golgi bodies (or Golgi apparatus)

• Typically reproduce by mitosis and meiosis

Antibiotics

Target bacteria

Taxonomy

The classification, identification, and naming of living organism

Nomenclature

the assignment of scientific names to individual organisms. A method commonly used to scientifically name microorganisms is the binomial (two-name) system.

Coccus (pl. cocci)

Round

Bachillus (pl. bacilli)

Rod

Vibro (pl. vibrios)

curved rod

Coccobacillus (pl. coccobacilli)

short rod

Spirillum (pl. spirilla)

spiral

Spirochete (pl. spirochetes)

long, loose, helical spiral

diplococcus

pair of two cocci

tetrad

grouping of four cells arranged in a square

streptococcus

chain of cocci

staphylococcus

cluster of cocci

diplobacillus

pair of rods

streptobacillus

chain of rods

palisade

V- or L-shaped formations of rods

Gram-positive bacteria

is bacteria with a thick cell wall composed of peptidoglycan and no outer membrane.

• Appear purple under magnification using the gram staining method

• Examples include species of Staphylococcus (S. aureus, S. epidermidis), species of Streptococcus (S. pyogenes, S. pneumoniae), species of Clostridium

Gram-negative

is bacteria with an outer membrane, a cytoplasmic membrane, and a thin cell wall.

• Outer membrane of gram-negative bacteria contains a molecule called lipopolysaccharide (LPS)

• LPS is an endotoxin that can stimulate fever and symptoms of shock in the host

• Appear pink under magnification using the gram staining method

• Examples include E. coli, Pseudomonas aeruginosa, species of Klebsiella.

pathogen

Any agent (usually a virus, bacterium, fungus, protozoan, or helminth) that causes disease.

inoculation

The implantation of microorganisms into or upon culture media.

Five I’s

Incoulation, Intubatuion, Isolation, Inspection, Identification

Liquid media

Growth-supporting substance in fluid form.

Water-based solutions that do not solidify at temps above freezing and that tend to flow freely when the container is tilted

semisolid media

Nutrient media with a firmness midway between that of a broth (a liquid medium) and an ordinary solid medium; motility media.

provide a firm surface on which cells can form discrete colonies

general-purpose media

designed to grow as many different types of microbes as possible

Material used to promote the growth of a broad array of microbes.

hemolysin

Any biological agent that is capable of destroying red blood cells and causing the release of hemoglobin. Many bacterial pathogens produce exotoxins that act as hemolysins.

refraction

In optics, the bending of light as it passes from one medium to another with a different index of refraction.

what are used by protozoa for motility

cilia, flagella, cytoplasmic extensions called pseudopods

yeast

unicellular

mold

multicellular

Heterotroph

Organism that absorbs or ingests organic food from the environment.

Nucleus

Contains the DNA of the cell and directs cellular functions. Stains as a dark, central circle within the cell.

oral groove

Ciliated channel that directs food to the mouth.

parent colony

Sphere of photosynthetic somatic (non-reproductive) cells and reproductive cells connected by cytoplasmic strands and extracellular matrix that make up a colony of Volvox.

pellicle

Protective protein layer on the cell membrane.

phagocytosis

Process by which cell membranes surround particles and engulf them. This is exhibited in amoeboids and other protozoans that lack a mouth and/or an oral groove.

pseudopodia

Foot-like extensions of the cell membrane created by cytoplasmic streaming and used for feeding and propulsion.

supergroup

Taxonomic group that lies between kingdom and domain. All organisms within the group evolved from a common ancestor.

vector

Organism that spreads pathogens between other organisms without causing disease itself.

mosquitos

vegetative cell

Flagellated somatic (non-reproductive) cells that make up the parent colony of Volvox.

biofilm

A complex association that arises from a mixture of microorganisms growing together on the surface of a habitat.

planktonic

Term referring to microbes that are free-floating in a liquid medium.

glycocalyx

A filamentous network of carbohydrate-rich molecules that coats cells.

outermost boundary that comes into direct contact with the enviroment (AKA extracellular matrix).