Chapter 5&7 Flashcards
Inhibits bacterial growth
Bacteriostatic
Chemical capable of killing bacteria
Bactericidal
Agent used to inhibit or kill growth, used on skin or mucous membrane
Antiseptic
An agent used to inhibit growth/kill bacteria on inanimate objects
Disinfectant
_______are stages in the life cycle of certain intestinal protozoan pathogens like Giardia lamblia. They are disinfectant-resistant forms that appear in the feces of infected animals, including humans. They are easily destroyed by boiling.
Cycsts
Enzyme that binds to DNA during replication and matches complementary base pairs. 5-3 direction
DNA polymerase
Makes primers with the use of RNA, needed to start DNA strand replication
primase
A series of three nucleotides that code for a specific amino acid
codon
Transcription vs translation
Transcription: info from DNA is encoded into RNA
Translation: mRNA is used to synthesize encoded protein (amino acid)
Nucleotide sequence RNA polymerase binds to start transcription
Promoter
Semiconservative
During binary fission, the replication of bacterial DNA, two molecules created contains one of the original stands paired with a newly synthesized strand
These enzymes temporarily break and unwind the DNA helix at the origin of replication (to initiate DNA replication, there is only ONE origin of replication in bacterial cells)
helicase and gyrase
anticodon
three complementary nucleotides in tRNA molecule that recognize and bind to associated mRNA
Inducible enzymes
Synthesis can be turned on as needed. The genes for the enzyme that hydrolyzes lactose are turned on when lactose is present.
Allows bacteria to “talk” to each other via molecule synthesis.
Low cell density=low signal molecule.
High cell density=high signal molecule.
At a certain density, the expression of genes changes.
quorum sensing
Repressible enzymes
enzymes that are produced routinely but their synthesis can be turned off when not required.
operon
PROG(t). closely related genes that act as a single unit
constituents of operon
promoter, repressor, operator, genes, terminator
DNA is synthesized in the ________ direction
5’ to 3’
Enzyme: joins DNA fragments on the lagging strand
DNA ligase
Enzyme: relieves tension from unwinding DNA strands; breaks hydrogen bonds
DNA gyrase
Enzyme: builds primers (3 nucleotide grouping of DNA to start replication at the fork or between lagging strands)
primase
start codon
AUG
STOP codons
UAG, UGA, UAA
What technique to use for controlling microbial growth on: drinking water
filtration
What technique to use for controlling microbial growth on: surface lab benches
U.V. (non-ionizing) radiation - less energy/longer waves
What technique to use for controlling microbial growth on: food such as fruits and meats to kill ENDOSPORES
Gamma (Ionizing) radiation - short wave, higher energy
What technique to use for controlling microbial growth on: sterilizing heat-sensitive solutions such as beer
Filtration
Chemical control: destroys cytoplasm membrane and denatures proteins, not good for skin. Very effective, found in Lysol
phenol/phenolics (used as antiseptic/disinfectant)
Chemical control: Damage proteins, not to be used as an antiseptic, could be used in small portions to clean water
Halogens (Chloride, Iodine)
Chemical control: Denatures proteins and lipid bilayer, common antiseptic in diluted portions. non-toxic, evaporate quickly
Alcohol
Chemical control: Interferes with protein/enzyme function by binding to sulfhydryl- groups. in bandaids, used to treat scratches. Not very many used due to environmental concerns.
Metal (silver nitrate)
Chemical control: Hydrophobic and hydrophilic regions, reduce the surface tension of liquids and wash away microbes
Quats (soaps)
Chemical control: Low toxicity, used in many antimicrobial products; disrupts cell-membrane
biguanides
