MICROBIOLOGY 130SURVEY OF MICROORGANISMS

(Read chapter 10 Tortora et. al., 7th ed. especially look at pages 276-285)

5 KINGDOM CLASSIFICATION SYSTEM:

o Procaryotes or monerao Protistao Fungio Plantaeo Animalia

3 DOMAIN CLASSIFICATION SYSTEM

o Archaeao Eubacteriao Eucaryotes

Naming and Classifying Bacteria

Genus - a group of closely related species

Species - a population of cells with very similar characteristics. Members of a species are practically indistinguishable from each other - but there are often some minor differences.

Strain - a population of cells derived from a single cell.

Sometimes bacterial names change frequently as new data comes to light. For instance in the last decade:

Pseudomonas solanacearum --> Burkholdaria solanacearum --> Ralstonia solanacearum

How do we classify bacteria into genera and species?

o Shape and stain characteristics (Gram Stain and Acid Fast Stain)

o Biochemistry -- which nutrients does the organism use for energy and carbon? What kinds of waste products does the organism make?

o Genetic characteristics -- G+C ratio, sequence of chromosome and or plasmids, sequence of specific genes (16s ribosome sequence)

 PRACTICAL OVERVIEW OF DIFFERENT TYPES OF ORGANISMS:

1. Prion -- infectious protein2. Virus

o Genetic particleo It has the information to reproduce - but only

when inside cellso No machinery of lifeo One nucleic acid only - either RNA or DNAo Protein coat - capsid, capsomereso May have envelope - a lipid bilayer membrane

3. Bacteria

o Procaryotico Single-celled organisms -- under proper

conditions these cells can reproduce freelyo Has both DNA and RNA in several different

organizations (chromosome, plasmid, ribosomes, etc.).

o Cytoplasm is not highly organizedo Cytoplasmic membraneo Cell wallo Locomotion based on flagella or axial filaments

4. Single Cell Eucaryotes

o Protozoa, Algae, Simple Fungi (Yeast)o These are eucaryoteso Single celled organisms - can reproduce freely

under suitable conditionso Contain both DNA and RNA - in several

organizations. Much of it in the nucleuso Cytoplasm - highly organized with many

organelles and a cytoskeleton. (mitochondria,

chloroplasts, various vacuoles, endoplasmic reticulum, golgi bodies, basal bodies, centrioles.)

o Locomotion based on flagella (cilia) and contraction (actin).

5. Multicellular Eucaryotes

o Higher Fungi, Plants, Animalso Basic organization of each cell is like it is in the

single-cell eucaryotes.o Individual cells are not normally free living. They

live in a "community" -- the body or soma of the organism.

o These organisms start off as a single cell.o The cell and its progeny undergo repeated rounds

off division resulting in a mass of cells. At certain times different groups of cells differentiate into cells with specialized function. Differentiation is the process by which certain cells in a multicellular organism acquire a special function and organize into unique tissues. In vertebrate animals, early in the life of the organism there are many cells which can individually differentiate into a complete organism. Such cells are called stem cells.

THE DIFFERENCE BETWEEN PROCARYOTES AND EUCARYOTES (also see chart on pg. 99 of Tortora et. al. 7th ed.)

Procaryotes - eubacteria and archaeobacteria

Eucaryotes - all other cells

Genetic info is free in cytoplasm Genetic info is enclosed in a membrane (nucleus). DNA is associated with proteins called histones.

Cell wall is usually present and it is chemically complex. In eubacteria it contains peptidoglycan (and teichoic acid

Cell wall is not found in animal cells. In plants it is composed of cellulose. In fungi it is composed of chitin. These are

in gram positive bacteria). polymers of glucose.No large internal organelles. But may find smaller inclusions and bubbles.

Many internal organelles within a highly organized cytoplasm.

Ribosomes are small - 70s Ribosomes are large - 80s; in the mitochondria and chloroplasts the mitochondria are small - 70s.

Locomotion with flagella made with flagellin; also axial filaments

Locomotion with flagella and cilia composed of microtubules (tubulin and dynein); also contractile motion based on actin and myosin.

 

A Brief Survey of MicroorganismsTools

Copy this to my account E-mail to a friend Find other activities Start over Help

A review of vocabulary found in Chapter 3 of "Fundamentals of Microbiology", 6th ed. by I.E. Alcamo (Jones and Bartlett).

A B

Animalia Kingdom of multicellular eukaryotes with ingestive nutrition

archaebacteria a group of bacteria thought to be ancient in

origin, live in extreme conditions

bacterium prokaryote

Bergey's Manual definitive listing of all known bacteria

binomial system classification scheme using two names to describe organisms

cellulose polysaccharide in cell wall of plants

cell wall fibrous accessory covering outside plasma membrane

centriole organelle that anchors eukaryotic flagella and cilia

chitin polysaccharide in cell wall of fungi

chlamydia small intracellular bacterial cause of pneumonia or STD

chloroplast photosynthetic organ of eukaryotes

chromosomes tightly coiled complexes of DNA and proteins

cilia eukaryotic organelle for movement, present in thousands

class nomenclature level between phylum and order

cyanobacteria photosynthetic bacterium, uses true chlorophyll

cytoskeleton fibers in cytoplasm of eukaryotes that shape and move cell

diatom unicellular algae with glasslike shells

dinoflagellate unicellular algae that move with use of two flagella

division equivalent to phylum for bacteria, algae, plants, protists

DNA heritable material

endoplasmic reticulum maze-like organelle used for protein synthesis and lipid metabolism

eukaryotic cells having nuclei and internal membranous organelles

family taxonomic level between order and genus

flagella long, hair-like organelles that generate movement by rotation or whipping motions

fluid mosaic model says cell membranes are phospholipid bilayers

with inserted proteins

Fungi Kingdom also known as Mycetae

fungus multicellular eukaryote with chitin in cell wall

genus first part of name in binomial nomenclature system

Golgi apparatus flat stacks of membranes involved in protein modification and routing

index of refraction ability of a substance to bend light passing through it

kingdom level of classification between empire and phylum/division

lysosome eukaryotic organelle for intracellular digestion

nomenclature system of naming things

membrane limiting boundary composed primarily of phospholipids

micrometer unit of measure equal to a millionth of a meter

mitochondrion dual membraned eukaryotic organelle that makes ATP

mold fuzzy form of fungus whose cells grow in filaments

Monera Kingdom name for bacteria

mycoplasma eubacteria that lack cell walls

nanometer unit of measure equal to a billionth of a meter

numerical aperture a measure of the size of the cone of light that enters the objective lens

order level of classification between class and family

organelle membrane-enclosed compartment in eukaryotic cells

peptidoglycan complex of amino acids and sugars - major component of eubacterial cell wall

phylum level of classification between kingdom and class

Plantae kingdom of multicellular, photosynthetic eukaryotes

plasma membrane outer limiting membrane of cell

plastid membranous storage vesicle in plants

prion infectious particles composed entirely of protein

prokaryotic cells lacking nuclei and membranous organelles

protist unicellular eukaryote

Protocista alternative name for Kingdom Protista

protozoa unicellular eukaryotes with ingestive nutrition

resolution ability to distinguish two points as separate

ribosome protein + RNA complex that makes proteins

rickettsia small bacteria that invade host cells - transmitted to humans by arthropods

RNA single stranded nucleic acid used to code for proteins

species most basic level of rank in a classification system

taxon level of classification

taxonomy study of classification of organisms

virus infectious particle composed of nucleic acid surrounded by protein coat

working distance amount of room between specimen and objective lens

yeast unicellular fungi that reproduce by budding