Defining the
Microbial World
Microbial World
This group of eukaryotic -often unicellular- microbes are distinguished by their motility
What are protozoans?
Any microbe that has the potential to cause infectious disease falls under this general term
What is a pathogen?
What is a flagellum?
While cellular organisms always use DNA as their primary genetic material, viruses can possess genomes made of either DNA or ....
What is RNA?
In clinical and some lab settings, this physical method is typically used to remove microbes from the air.
What is filtration?
This genetic event leads to spontaneous DNA sequence changes in the bacterial genome
What is a mutation?
Viruses, phage, and prions share this characteristic that prevents them from being considered "living."
What is the inability to replicate independently?
By competing for nutrients and preventing pathogen attachment to tissues, our normal flora provide this benefit.
What is protection from infection?
Bacterial ribosomes are destroyed by an antibiotic.
The most immediate result is ...
What is protein synthesis stops?
An obligate intracellular parasite is...
What is a microbe that only can grow and divide inside host cells?
Freezing ground beef only stalls growth and is not considered this type of "killing"
What is bactericidal?
A protein's final form and function are largely determined by its specific sequence of these building blocks.
What are amino acids?
"Microbe" refers to these
3 types of microorganisms ...
What are prokaryotes, eukaryotes, and acellular infectious particles?
During the first three years of life, the human microbiome undergoes this primary change in its composition.
What is "it becomes more diverse"?
This unique cellular feature gives Gram-negative bacteria greater resistance to antimicrobials than Gram-positive bacteria
What is the outer membrane?
An antiviral drug blocks the assembly -but not attachment- of new viral particles in a host cell. The consequence of this drug on the viral life cycle is...
What is viral particles are not released from cells?
This process of destroying pathogenic bacteria is more effective than pasteurization, sanitation and refrigeration.
What is sterilization?
Bacteria can directly "acquire" genes from a neighboring cell through a conjugation pilus in this process.
What is conjugation?
Unlike eukaryotic cells, prokaryotic cells are defined by lacking this internal structure.
What is a nucleus or an organized compartment for DNA?
An opportunistic microbe causes ...
What are infections in compromised hosts?
Infections caused by these microbes can be treated with drugs that bind to prokaryotic ribosomes
What are bacteria?
Because viruses offer minimal targets for these drugs, their infections in humans are usually more difficult to treat than bacterial infections.
What are antimicrobials or antibiotics?
Because it possesses a fragile lipid membrane, this type of virus would likely be most sensitive to an alcohol-based hand sanitizer.
What is an enveloped virus?
A plasmid with the gene for a human growth hormone is transferred into E. coli so that the bacterium produces the hormone. What form of gene transfer does this describe?
What is transformation?
You are observing an infectious agent under a microscope. It lacks a membrane and cannot reproduce without a host cell. It is this type of particle.
What is an acellular infectious particle (or virus/phage/prion)?
These substances are thought to support the growth of commensal microbes living in our gut, whereas live beneficial microorganisms are consumed as these.
What are prebiotics and probiotics?
Because they possess this structure, certain bacteria can persist for long times under harsh environmental conditions and resist routine disinfectants.
What is an endospore?
This type of virus specifically targets bacteria, transferring genes to them
What is a bacteriophage?
To clean up a room contaminated with the endospore-producing pathogen Clostridium difficile, you should use this specific type of disinfectant solution instead of quats or alcohol
What is a bleach-based solution?
Through a process called transduction, bacteria can obtain genetic material by means of these specialized acellular agents.
What are bacteriophages?