Microbiology Introduction Flashcards
What are prions?
aggregates of proteins that have mutated somehow and cause some trouble in the body
What is an obligate intracellular pathogen?
pathogens that require other cells to multiply
What are the main differences between prokaryotes and eukaryotes?
prokaryotes have fewer organelles, no nucleus, and a cell wall
What are some aspects of bacteria that are targetable by drugs/medications?
peptidoglycan in the cell wall (not present in people), ribosome is slightly smaller than human ribosome
What are some different classes of microbes?
Prions, Viruses, Bacteria, Fungi, Protozoa, Helminths
this list is organized by size.
what are helminths?
“worms” like roundworms, tapeworms. visible to the eye, eukaryotes
What limits bacterial growth?
Nutrients, space, disease
What are different forms of horizontal gene transfer in bacteria?
Phage Transductance - virus will infect bacteria, multiply, leave bacteria, infect new bacteria cells. But! Virus sometimes picks up bacterial DNA instead of viral DNA and will pass the bacterial DNA to the newly infected DNA.
Transformation - passive transfer of DNA by picking
Conjugation - direct transfer of plasmids by contact between bacteria
What type of genetic material do plasmids contain?
Plasmids usually contain extracellular genetic information that you don’t “need” to function but that add to the functions of a cell. Bacteria will have additional virulence factors or antiobiotic resistance or toxins in plasmids.
What are - sense RNA viruses?
Negative sense RNA viruses are viruses which bring along the opposite strand of RNA that they need to create proteins. So they need to bring along reverse transcriptase or an RNA-dependent RNA polymerase to create the complement and create the proteins.
What are + sense RNA viruses?
Positive sense RNA viruses are able to have their proteins translated immediately by the host cell
What organelles do viral genes make? What organelles do viruses take advantage of in the host cell?
viruses only have genetic code for regulating the host cell and making their protein coat and organizing everything into a cluster. they do not have genetic code for making mitochondria, or ribosomes, or plasma membranes. They steal all of this from the host cell.
What type of polymerases are available naturally in human cells?
DNA-dependent DNA polymerase
DNA-dependent RNA polymerase
Are viruses with lipid envelopes more or less stable than viruses with just a protein coat?
Less stable! If the lipid membrane is dessicated (dissolved), they lose their infectious factors and aren’t able to infect host cells anymore. They just become blobs of DNA or RNA in a protein shell. Protein only viruses have the infectious factors on their protein coat which is much more robust.
How does a virus infect a cell?
Viruses recognize target cells by interacting with extracellular receptors. The cell will either be tricked into letting the virus in, the virus will force itself in, or the virus (phage is a virus that infects bacteria) will inject its genetic material. The protein coat dissolves and the viral genome is replicated. The virus eventually takes over the cell, re-assembles its protein coat, and breaks free of the cell
What is reverse transcriptase?
an enzyme used to generate complementary DNA (cDNA) from an RNA template. This DNA is then replicated by the host cell and eventually transcribed/translated into protein
What does - sense RNA viruses need to bring with it into a new host cell?
needs to bring an RNA-dependent RNA polymerase or a reverse transcriptase enzyme! Otherwise it can’t start the multiplication process.
What types of genetic information can be found in viruses?
RNA, DNA. Single Stranded RNA (+ or -) double stranded RNA