Viruses & Prokaryotic Microbes 4

Flashcards covering Viruses and Prokaryotic Microbes lecture notes.

Bacteria

Prokaryotic microbes divided into three phenotypic categories: Gram positive, negative, and those lacking a cell wall.

Bacterial Cell Morphology

Varies in size and shape; three basic shapes are round/spherical, rectangular/rod-shaped, and curved/spiral-shaped. They divide via binary fission.

Diplococci

Cocci arranged in pairs (e.g., Neisseria gonorrhoeae, which causes gonorrhea).

Streptococci

Cocci arranged in chains (e.g., Streptococcus pyogenes, which causes strep throat).

Staphylococci

Cocci arranged in clusters (e.g., Staphylococcus aureus, which causes boils).

Bacterial Cell Motility

The ability to 'swim,' often associated with flagella or axial filaments; cocci are generally non-motile.

Obligate Aerobes

Require an atmosphere containing molecular oxygen in concentrations comparable to room air (20%-21% oxygen).

Microaerophilic Aerobes

Require oxygen for multiplication but in lower concentrations than room air (prefer 5% oxygen).

Obligate Anaerobes

Can grow only in an anaerobic environment (without oxygen).

Aerotolerant Anaerobes

Do not require oxygen but grow better in its absence; can survive in atmospheres containing molecular oxygen.

Facultative Anaerobes

Capable of surviving in either the presence or absence of oxygen (anywhere from 0% to 21% oxygen).

Capnophiles

Grow better in vitro with an increased concentration of carbon dioxide.

Unique Bacteria

Rickettsias, chlamydias, and mycoplasmas, which do not possess all attributes of typical bacterial cells and are small and difficult to isolate.

Chlamydias

Energy parasites that prefer to use the ATP of host cells; obligate intracellular pathogens (e.g., C. pneumoniae, which causes pneumonia).

Mycloplasmas

The smallest of the cellular microbes; lack cell walls and appear pleomorphic; resistant to antibiotics that inhibit cell wall synthesis.

Domain Archaea

More closely related to eukaryotes than bacteria; most are extremophiles, and their cell walls do not contain peptidoglycan.

Extremophiles

Organisms that thrive in extreme environments, such as acidophiles (acidic), alkaliphiles (alkaline), thermophiles (hot), psychrophiles (cold), halophiles (salty), and piezophiles (high pressure).

Viruses

Acellular microbes that contain either DNA or RNA surrounded by a protein coat (capsid).

Virions

Complete virus particles, ranging from 10 to 300 nm in size.

Oncoviruses

Viruses that cause cancers, such as lymphomas, carcinomas, and some leukemias.

Capsid

Protein coat surrounding the nucleic acid of a virus, composed of small units called capsomeres.

Nucleocapsid

The nucleic acid and capsid of a virus.

Bacteriophage

Bacterial viruses that do not have an envelope.

Provirus

Viral DNA that has integrated into the host cell's DNA.

Latent Viral Infections

Infected individual always harbor the virus with minimal to asymptomatic; Is limited by the immune system; When immune system becomes weaker, disease will appear

Animal Viruses

Viruses that infect humans and animals; contains either DNA or RNA; may only have nucleic acid and capsid or nay be complex

Viroids

Small infectious proteins that cause fatal neurologic diseases in animals & humans; small, naked fragments of single-stranded RNA that attack plants.

Prions

Small infectious proteins that cause fatal neurologic diseases in animals & humans; all diseases are untreatable and fatal; mechanism to cause disease remains a mystery; most resistant to destruction