Subgroups of species that have special characteristics to survive in their ecological surroundings
That part of the earth where life occurs, including air, soil and water
Maintain a relatively steady internal state
Homeo = similar
Statis = state
Bacterial cells live in communal associations where survival requires chemical communication between cells.
The cells become embedded in a matrix of excreted polymeric substances
Consists of charged and neutral particles that hold the biofilm together and cement to surfaces
Ability of bacteria to sense their numbers and then communicate and coordinate behavior, including gene expression via signaling molecules
AKA plasma membrane
The internal cell environment in which chemical reactions occur
If all the cell structures are removed from the cytoplasm, cytosol remains and consists of water, salts, ions and organic compounds.
An RNA protein machine that cranks out proteins based on the genetic instructions it receives from the DNA.
Although the pattern for protein synthesis is identical, structurally bacterial ribosomes are smaller than their counterparts in eukaryotic cells
Reader of RNA to make protein
Structurally discrete, often membrane enclosed, sub-cellular compartments that carry out specialized functions. Bacterial cells also have subcellular compartments that are not readily visible or membrane enclosed.
Designed to transport protein and lipids into an out of eukaryotic cells.
Consists of flat membranes to which ribosomes are attached (rough ER involved in protein and lipid synthesis) and tube like membranes without ribosomes (smooth ER involved in protein and lipid transport).
Membrane enclosed spheres involved with secretion and storage
A group of independent stacks of flattened membranes and vesicles where the proteins and lipids coming from the ER are processed, sorted and packaged for transport.
Somewhat circular membrane enclosed sacs containing digestive (hydrolytic) enzymes and are derived from the Golgi apparatus and in protozoal cells break down captured food materials.
Areas of bacteria cells that represent a type of organelle
All cells convert chemical energy into cellular energy for cellular work.
In eukaryotic microbes, this occurs in the cytosol and mitochondria
In prokaryotic microbes this occurs in the cytosol and cell membrane
Conversion of light energy into chemical energy.
Some bacteria such as cyanobacteria can do this
Interconnected system of cytoplasmic fibers, threads, and interwoven molecules that give structure to the cell and assist in the transport of materials throughout the cell. Bacterial cells don't have a cytoskeleton.
Microtubules that are the main components of the cytoskeleton and originate from the centrosome and microfilaments, each assembled from different protein subunits.
Mechanical force for motility
Bacteria don't have
Homeostasis is an organism's ability to maintain a stable internal state
Many prokaryotes live in communal associations called biofilms
Myxobacteria live in a social community dependent on cell-to-cell interaction and communication
Prokaryotes carry out many of the same cellular processes as eukaryotes
All organisms have similar genetic organization whereby heredity material is expressed
Both prokaryotic and eukaryotic cells have internal compartments
Metabolism occurs in the cytoplasm
Ribosomes are involved in protein synthesis
Both eukaryotes and prokaryotes use flagella for motility, though the flagella differ structurally and functionally in the two groups
Many prokaryotes and eukaryotes have a cell wall to help maintain water balance
Prokaryotes and Eukaryotes Distinctions
Eukaryotes have membrane-enclosed organelles
Protein/lipid transport in eukaryotes is carried out by the endoplasmic reticulum and Golgi apparatus
Mitochondria perform cellular respiration in eukaryotes
Both eukaryotes and prokaryotes can perform photosynthesis
Prokaryotes and Eukaryotes: The Structural Distinctions
The eukaryotic cytoskeleton gives the cell structure and transports materials within the cell
Prokaryotes and Eukaryotes Differences
1 circular chromosome
Complex cell wall
More than one chromosome
No or simple cell wall
Prokaryotic cells contain
Eukaryotic cells contain
Ribosomes attached to endoplasmic reticulum
Smooth endoplasmic reticulum
Rough endoplasmic reticulum
All the chemical reactions occurring in an organism or cell
Taxonomy is the science of classification, involving arranging related organisms into logical categories.
Domain - ie Eukarya
Kingdom - ie Animalia
Phylum - ie Chordata
Class - ie Mammalia
Order - ie Primates
Family - ie Hominidae
Genus - Homo
Species - sapiens
Monera - Prokaryotae, bacteria
Protistas - make own food & move
Fungi - Don't make their own food
In the mid-1700s, Carolus Linnaeus published Systema Naturae, establishing a uniform system for naming organisms
Scientific Organism Names
Each name includes two words, the genus and the specific epithet
Binomial Classification, Nomenclature
Used by Linnaeus
Underline if writing, italics if typing
Uses a hierarchical system
Species (least inclusive) to kingdom (most inclusive)
The five kingdom system
Who developed the five kingdom system?
Robert H. Whittaker and Lynn Margulis developed the five-kingdom system, giving bacteria their own kingdom.
List the hierarchy of classification
The Three Domain System
Proposed by Carl Woese based on data from ribosomal RNA sequences
Distinguishing between prokaryotes
Experiments on physical characteristics, biochemistry, serology (antibodies), and nucleic acids can be done to identify microbes
Molecular taxonomy is bases on sequences of nucleic acids in ribosomal RNA
The dichotomous key can be used identify microbes
1000 mm = 1 meter
1000 um = 1 mm - 1 millionth of a meter
1000 nm = 1 um - 1 billionth of a meter
Where can the proper taxonomic classification for Bacteria and Archaea be found?
Bergey's Manual of Systematic Bacteriology.
The first two volumes of this 5-volume compendium have been published.
What is used to identify medical identifications?
Bergey's Manual of Determinative Bacteriology
What are the physical characteristics of microbes used for classification?
Shape - staining allows us to see the shape
Growth requirements (Oxygen, Ph, Temp)
Biochemical Characteristics (fermentation of carbs, use of a specific substrate, waste products)
Based on the universal presence of ribosomes in all living organisms.
Ribosomal RNA (rRNA) is the basis for the three domain system (Bacteria, Archaea, Eukarya)
A popular version is to construct a flow chart where a series of positive or negative test procedures are listed down the page.
Based on the dichotomous nature of the test (always positive or negative) the flow chart leads to the next test result.
Size of organisms
Protozoa: 100 um
Molds: 10 x 40 um
Yeasts: 8 um
Bacteria: 1 - 5 um (.25-20um)
Viruses: 200 - 250 nm*
*250nm = .25 um
Is Used to Observe Most Microorganisms
Visible light passes through multiple lenses and through the specimen
Light microscopes usually have at least 3 lenses: low-power, high-power, and oil-immersion
The lens system must have high resolving power to see the specimen clearly
Blue light has a short wave length therefore has more energy
Parts of a microscope
What does a microscope do?
Increases resolution - the ability to see things that are close to each other.
What does the oil immersion lens do?
Allows light to travel in a straight line from lens to specimen so that it can be seen clearly. Without the oil, light would bend away from the specimen.
What color light has more energy?
Blue. It has a shorter wave length
How do you calculate resolving power?
Wavelength of light (550nm)/2*numerical aperture of the lens
i.e. 550/(2*1.25) = 55/2.5 = 220 nm or .22 um
Magnification and resolution define the limits of what is visible
The practical limits of an electron microscope is 2nm, 100x better than the resolving power of a light microscope
Index of refraction
A measure of the light bending ability of a medium
Simple stain technique
Just add dye
Stain everything but the cells. Looks like a negative photo