Exam 2 Flashcards
Disinfection of living tissue using a chemical agent. Safe on skin, could be alcohol, hydrogen peroxide
Antisepsis
Reduce the number of pathogens to meet public health standards
Sanitization
Use of heat to reduce the # of spoilage organisms in food or beverages
Pasteruization
3 modes of actions of microbrial control agents? How do they kill microbes?
- Alters membrane permeability
- Denatures proteins by disrupting 3d structure so that proteins cannot function
- Damages nucleic acids: DNA + RNA
Destroying microbes on inanimate objects or surfaces
Disinfecting
Killing any and all microbes
Sterilization
What is that action to bacteria and cells from radiation?
Damages nucleic acids
3 examples of using heat to denature protein + kill
- Bacticinerator
- Dry heat/hot air
- Moist heat
Examples of moist heat
Holding method (62.9 C for 30 min)
Flash method (71.6 C for 15 sec)
Ultra high temp method (140 C for 3 sec)
What type of heat is from an autoclave? 121 C at 15 lbs of pressure for 15 min
Moist heat + pressure
What are the two type of radiation?
Ionizing and non-ionizing
Examples of ionizing radiation and what it can be used on
-Gamma + X-rays
-Can preserve food
-Can be used on protein-based drugs
-Vaccines
-Plastic instruments
Examples of non-ionizing radiation and what is can be used on
-UV light (mismatch nucleotides)
-Used in OR, Morgues, and Labs
What is the action of osmosis on bacteria?
Shrivels or burst the microbe
High sure or salt water osmose OUT of the cell
What is the action of filtration on bacteria?
Pores in filter that trap microbes.
-Surgical maskm HEPA filters in heating + AC
-Some drugs get filtered
What is the action of cold on bacteria?
Slows growth, metabolism, and reproduction
Lyothalization
Removes water under a vaccum and decreases metabolism in bacteria
Action of of Phenols + Phenol derivatives
Alters membrane permeability and denatures proteins
Phenol…
Poor solubility
Is caustic to skin
Can damage CNS
Stinks
Action of aldehydes
Denatures proteins
Types of aldehydes
Formaldehyde
Formalin
Glutaraldehyde
OPA
What is the action of surfactants?
Mechanical removal of microbes
The action of hydrogren peroxide?
Free radicals -OH are toxic and damage cells by stealing electrons
Alexander Flemming
Left streak plate open + mold got into it.
Antibiotics were discovered
Define antibiotic
A substance naturally produced by a few bacterial and fungal species that inhibits or kills bacteria
Antibiotics only kill what?
Bacteria
Five target of antibiotics
- Bacterial cell wall
- Disrupting/disorganizing membranes
- Nucleic acid synthesis
- Block protein synthesis
- Metabolic pathways
What did we use before antibiotics?
Enema, blood-curdling ice baths, deadly starvation, bloodletting
Who discovered antibiotics?
Alexander Flemming
Bacterial DNA is super-coiled via an enzyme called _________
Gyrase
What is the shape of the bacterial chromosome?
Circle
How many chromosomes do bacteria usually have?
2
A plasmid carries essential information
False
Plasmids have to replicate when the bacterial chromosome replicates
False, it replicates independently
A small, circular DNA separate from the bacterial DNA is a(n)
Plasmid
The monomer of nucleic acids
Nucleotides
Nucleotides are composed of
sugar, a phosphate group, and a nitrogenous base.
The nitrogenous bases in DNA are
Adenine
Thymine
Cytosine
Guanine
How many strands does DNA contain?
2
The building block of nucleic acids is glycerol and fatty acids
False (nucleotides)
The specificity of DNA is in the
Order of the nucleotides
The building block or monomer of DNA and RNA is
Nucelotides
The sugar in DNA is
Deoxyribose
A _ is a specific sequence of nucleotides that codes for a protein or RNA
Gene
DNA is a nucleic acid
True
A _____ is the entire genetic complement of a cell or virus
Genome
The sugar in RNA is
Ribose
Nitrogenous bases in RNA are
Adenine
Uracil
Cytosine
Guanine
What are the three types of RNA?
Transfer, messenger, and ribosomal RNA
How many strands does RNA have?
1
One strand (the 5’ or five prime strand) has
A terminal phosphate group
The other strand (the 3’ or three prime strand) has a
Terminal hydroxyl group
Acts as a go between between DNA and protein
Messenger (mRNA)
Ribosomes along with proteins are what RNA is made of
Ribosomal (rRNA)
Transfers amino acids
Transfer (tRNA)
An enzyme called ________ unwinds and unzips the DNA at the ori site
Helicase
_______ adds complementary nucleoties in the 5’ > 3’ direction
DNA Polymerase
The strand that is replicated continuously is called
The leading strand
The DNA strand that’s replicated in fragments is known as
Okazaki fragments
What are Okazaki fragments knitted(seal) together by?
DNA Ligase
What direction does DNA polymerase make strands in?
5’ > 3’
The process of DNA being converted to mRNA is known as
Transcription
The process of mRNA being converted to protein is known as
Translation
moves along the DNA strand that is serving as the template and adds complementary nucleotides and builds the mRNA strand (transcription)
RNA Polymerase
Transcription occurs in ______ of prokaryotic cell
Cytoplasm
Transcription takes place in the ______ in eukaryotic cell
Nucleus
In transcription _____ is transcribed into _____
DNA, mRNA
How many DNA strands serve as a template in transcription?
1
Action of alcohol on bacteria
Damages membranes and denatures proteins
The action of gaseous sterilizer on bacteria
Denatures protein
Action of hydrogen peroxide on bacteria
Free radicals are toxic and damage cells by stealing electrons
Water disinfection
Ozone
Halogens actions on bacteria
Denatures proteins
Heavy metals on bacteria
Denatures proteins