Exam 3 Flashcards
____ is the study of heredity
Genetics
____ is the transmission of genetic material from an organism to its progeny.
Heredity
____ is a specific sequence of nucleotides that encodes for a polypeptide and is a functional unit of DNA.
Gene
____ is the genetic information inside an organism or virus. (contains essential genes for structure and function.)
Genome
___ is an alternate form of a gene.
It occupies the same place on the DNA molecule as another form but can carry different information for a trait.
Allele
____ is a structure that contains the DNA of organisms.
Chromosome
____ is the gene sequence/genetic information contained int he DNA of an organism.
Genotype
____ is the physical appearance/specific observable characteristics displayed by an organism.
Phenotype
4 nucleotides that make up DNA.
Adenine
Thymine
Guanine
Cytosine
4 nucleotides that make up RNA.
Adenine
Guanine
Cytosine
Uracil
____ opens up the DNA double helix in replication. (Unzips/unwinds the double helix)
Helicase
____ is the enzyme that copies during DNA replication. (DNA to DNA)
DNA Polymerase
____ is the synthesis of mRNA from a DNA template.
Transcription
____ is the synthesis of DNA from a DNA template.
Replication
____ is the synthesis of a protein from information in mRNA.
Translation
____ are basically extra genes that give bacteria something beneficial. (SMall, circular, independently replicating piece of DNA in a cell that is not part of its chromosome and can be transferred to another cell.)
Plasmid
Bacteria have how many copies of a gene?
1
What are the 3 kinds of RNA.
ribosomal RNA (rRNA) messenger RNA (mRNA) transfer RNA (tRNA)
A promoter is what in transcription.
The start of a gene.
Beginning [place] of transcription
What is the function of RNA polymerase?
Opens up the DNA double helix and and copies it to RNA.
Where does transcription take place in prokaryotic cells?
Cytoplasm
Where does transcription take place in eukaryotic cells?
Nucleus
____ carries information from DNA for protein synthesis.
mRNA
____ has base triplets called codons that constitute the genetic code.
mRNA
____ is found in the cytoplasm, where they pick up amino acids and “transfer” them to mRNA.
(Transfers amino acids to proteins.)
tRNA
____ has single triplet of bases called and anticodon.
pairs complementarily the corresponding codon in mRNA
tRNA
____ is a sequence of three bases (triplet) in mRNA that make amino acids.
Codon
A ____ specifies a particular amino acid or acts as a terminator/stop ____.
Codon
____ is the one to one relationship between each codon and a specific amino acid.
Genetic Code
____ is the first codon in a molecule of mRNA.
Start Codon
____ is the last codon to be translated in a molecule of mRNA.
Stop Codon
____ begins the sequence of amino acids in protein synthesis. (Always codes for Methionine in bacteria.)
Start Codon
____ causes the ribosome to release from the mRNA.
Stop Codon
____ is a start codon marking the beginning of protein synthesis.
AUG
____, ____, & ____ are the 3 stop codons which stops translation.
UAA
UGA
UAG
____ is the flow of genetic information.
Genetic Dogma
____ is a heritable change in the gene sequence (DNA)
Mutation
A ____ is a base substitution, or nucleotide replacement, in which one base is substituted for another at a specific location in a gene.
Point mutation
A ____ results from the deletion or insertion of one or more bases.
Frameshift mutation
____ occur in the absence of any agent known to cause changes in DNA. (usually caused by an error in DNA Replication.)
Spontaneous Mutation
A ____ is produced by agents called mutagens that increase the mutation rate.
Induced Mutation
____ is an went that increases the rate of mutations.
Mutagen
____ is the killing or removal of “all” microorganisms in a material or on an object.
Sterilization
Is it possible to sterilize skin?
No. Only by burning.
____ describes an environment or procedure that is “free” from contamination by pathogens.
Aseptic
____ is the process of “reducing” or inhibiting microbial growth by applying “chemicals” to inanimate objects.
Disinfection
____ is the application of “chemicals” (antiseptic) to “living tissue” to reduce or inhibit microbial growth.
Antisepsis
____ is the removal of microbes from a surface by “scrubbing.”
Degerming
____ is a chemical agent typically used on food-handling equipment and eating utensils to reduce bacterial numbers.
Sanitizer
____ is lowering the number of pathogens on objects to safe “public health levels” using “chemicals.”
(to minimize disease transmission)
Sanitization
-cide/-cidal refers to what?
Destruction/death of the organism
-stasis/static refers to what?
Inhibition but not complete destruction
____ is the “permanent loss” of reproductive ability under ideal environmental conditions.
(IS CONSTANT OVER TIME)
Microbial Death
3 factors to consider in selecting a microbial control agent.
- Nature of the sites to be treated
- Degree of susceptibility of the microbes involved
- Environmental conditions that pertain
Name at least 2 environmental conditions that pertain to microbial control agents.
- Temperature
- pH
- Organic materials
____ uses a high temperature for a short time to destroy pathogens without altering flavor of for or beverage.
(does NOT sterilize)
Pasteurization
____ is a mutation where you change the codon but do not change the amino acid.
Silent Mutation
____ is a mutation where both the codon and the amino acid changes.
Missense Mutation
What is meant when it is said that the genetic code is universal?
The genetic code is the same in every organism
What is meant when it is said that the genetic code is non ambiguous?
The same codons stay with the same Amino Acids
What is meant when it is said that the genetic code is degenerate?
There is more that one codon from some Amino Acids
4 major steps of elongation of translation.
- tRNA enters A site carrying Amino Acids
- Peptide bond form between Amino Acids in the P&A sites
- tRNA lets go of Amino Acid in P Site and tRNA exits the ribosome
- Translocation occurs. (Ribosome movement) Ribosome moves down mRNA by 1 codon A Site is empty.
2 main functions of DNA
- Stores genetic info
2. Can be easily copied
3 most resistant groups of microbes.
Bacterial endospores
Mycobacterium
Cysts of protozoa
Importance of refrigeration and freezing in limiting microbial growth.
Both inhibit metabolism
How is hypertonic solutions used in microbial control.
Microorganisms are placed in a high concentration of sugar or salt to remove the water from inside the cell to inhibit cellular metabolism.
____ is referred to as ionizing radiation.
Gamma Radiation / X-rays
____ is referred to as non ionizing radiation.
UV Radiation
3 functions of ionizing/Gamma radiation.
High penetration
Destroys DNA
Used to sterilize medical and dental supplies
2 functions of UV radiation
Low Penetration
Damages DNA
____ denature proteins, dissolve lipids, damage membranes, (kill bacteria, enveloped viruses and fungi).
Alcohols
Why do 70% and 90% alcohols work better than pure alcohols?
When mixed with water they denature protein and they stay in contact with the area longer whereas pure alcohol evaporates quickly.
4 halogens.
Iodine Chlorine Bromine Fluorine (Bleach)
2 iodophors.
Betadine
Isodine
____ a halogen that inactivates enzymes and cellular proteins and helps control microbes in pools and drinking water and food utensils.
Iodine
_____ is a halogen that forms hypochlorus acid in water,, and is found in swimming pools, drinking water, and sewage wastewater treatment.
Chlorine
What is the action of halogens?
Denature protein
Peroxides, Ozone, and Peracetic Acid are all ____.
Oxidizing Agents
What is the function of Oxidizing agents?
Denature proteins by oxidation
What are some uses of Oxidizing agents?
Disinfectants,
Antiseptics for deep wounds
Water purification
sterilization of medical equipment
____ decrease tension between molecules on the surface of a liquid. (Soaps & detergents)
Surfactants
What is the action of Surfactants.
Decrease the surface tension of water
Disrupt cell membranes
Silver, Mercury, Zinc, Coppper, and Selenium are all ____.
Heavy Metals
What is the action of heavy metals?
Denature proteins.
What is the use of copper in microbial control?
Acts as an algicide in water reservoirs, swimming pools, and aquariums
What is the use of silver in microbial control?
Bandaids, surgical instruments etc.
____ are the most effective antimicrobials
Aldehydes
Compare and contrast formaldehyde and glutaraldehyde.
Formaldehyde: (disinfectant/ embalming fluid) more irritating to mucous membranes, less expensive, is carcinogenic, and used to embalm.
Glutaraldehyde: (disinfect/sterilize medical and dental equipment) less irritating, more expensive, used as 2% solutions in hospitals and dental offices.
Advantages & disadvantages of gaseous agents.
Advantages: penetrate most materials and kills all microorganisms by denaturation, used on heat-labile materials, and sterilize.
Disadvantages: explosive, poisonous, and potentially carcinogenic
____ is the term coined by Paul Ehrlich to describe the use of chemicals to kill pathogens without injuring the host?
Chemotherapy
____ are chemicals used internally to treat disease?
Chemotherapeutics
____ is a special group of chemotherapeutics used to treat disease caused by microbes?
Antimicrobial Agents
____ are chemical substances produced by microorganisms which have the capacity to inhibit the growth of or kill microorganisms.
Antibiotics
____ are chemical agents made in the lab.
Synthetic drugs
____ are synthetic precursors given to microorganisms which completes the synthesis of antibiotic with it metabolism.
(partially made by humans & partially made by microbes)
Semisynthetic drugs
____ was the first antibiotic.
Penicillin
What marked the beginning of modern medicine?
The introduction of penicillin and sulfonamides in the 1930’s.
____ is the property of an antimicrobial drug to be toxic to the microbe while being nontoxic to the host.
Selective Toxicity
Why are there ore antibacterial drugs than antiviral, anti fungal and anti protozoan?
Bateria are easier to kill because they are prokaryotic and have a cell wall. Bacteria are extracellular and can kill them without killing host.
To kill viruses you must kill the host cell because viruses are obligate intracellular parasites.
Under 1% of infectious diseases are caused by fungus and protozoan.
____ are agents that are effective agains a great number of microorganisms. (bot G+ and G-)
Broad Spectrum
____ are agents that are effective on a small number of organisms.
Narrow Spectrum
What is the physical method that would be used to sterilize a heat-sensitive liquid, such as a solution of antibiotic penicillin.
Membrane filtration
What would be the best way to sterilize a sealed, plastic sleeve of plastic Petri dishes?
Gamma Rays
Lysol, a disinfectant, is categorized as what type of chemical disinfectants?
Phenolic
What type of chemical agent is silver nitrate?
Heavy Metal
A ____ is a disinfectant that “contains” alcohol.
Tincture
Gamma Radiation sterilizes objects by doing what?
Damaging DNA
Transcription produces ____ from ____.
RNA from DNA
Transcription begins where?
Promoter sequence on the DNA
Replication begins where?
Origin of replication on the DNA
Translation begins where?
AUG codon on the mRNA
A point mutation that changes a base in the coding region of the DNA from an amino acid codon into a stop codon is a ____.
Nonsense mutation
