Classification and Structure and Function of Microbial Organisms Flashcards
What are characteristics of the bacteria (eubacteria)?
They are prokaryotes, lacking a true nucleus.
Their cell membranes consist of unbranched fatty acid chains attached to glycerol by ester linkages.
Bacterial cell walls contain peptidoglycan, providing structural support.
Bacteria are ubiquitous, found in various environments including the gut microbiome and as producers of antibiotics.
Most bacteria are not clinically significant in causing disease.
What are the characteristics of Archaea (archaebacteria)?
Archaea are prokaryotic organisms.
Their cell membranes have branched hydrocarbon chains attached to glycerol by ether linkages.
Unlike bacteria, their cell walls contain no peptidoglycan.
They often live in extreme environments.
An example is Thermus aquaticus, which provides Taq polymerase used in PCR.
Archaea typically have no clinical significance.
What are the characteristics of Eukarya (eukaryotes)?
Eukaryotic cells
Membranes composed of unbranched fatty acid chains attached to glycerol by ester linkages
Not all eukaryotes have a cell wall, and those that do lack peptidoglycan
Eukarya includes Protista (unicellular organisms like protozoa and algae) and Fungi (unicellular or multicellular organisms like yeasts and molds)
What is the composition of membranes in eukaryotic cells?
Membranes in eukaryotic cells are composed of unbranched fatty acid chains attached to glycerol by ester linkages
Do all eukaryotes have a cell wall? If yes, what is its composition?
Not all eukaryotes have a cell wall. Among those that do, they lack peptidoglycan in their cell walls.
What are examples of organisms included in the Protista kingdom?
Protista kingdom includes unicellular organisms such as protozoa and algae
What types of organisms are classified under the Fungi kingdom?
Fungi kingdom includes both unicellular (e.g., yeasts) and multicellular (e.g., molds) organisms.
What organism is associated with colitis?
Clostridium difficile.
What type of bacterium is Clostridium difficile?
Gram-positive bacterium.
To which phylum does Clostridium difficile belong?
Phylum: Firmicutes.
In which class is Clostridium difficile classified?
Class: Clostridia.
What are the dimensions of Clostridium difficile?
It is 15 μm long x 1.5 μm wide.
What unique characteristic allows Clostridium difficile to persist in the environment?
Spores
Where does Clostridium difficile colonize before causing diarrhea/colitis?
It colonizes the colon
What is the causative organism of Bubonic Plague
The causative organism of Bubonic Plague is Yersinia pestis, a Gram-negative bacterium belonging to the phylum Proteobacteria and class Gammaproteobacteria. It is approximately 1.5 μm long and 1 μm wide. Bubonic Plague is transmitted primarily by rodent fleas.
