1.2 MI Study Guide PLTW Flashcards
Antibiotics
a substance produced or deprived by a microorganism that are able to inhibit or kill another microorganism.
Gene
Segment of DNA codes (nucleotides)
What determines the effectiveness of antibiotics?
The action of a drug and the structure of the bacteria
How do penicillins (also called β-Lactam antibiotics) affect bacteria?
A wide range antibiotics that interfere with the synthesis of peptidoglycan (Cell wall) and target gram positive bacteria. They produce and enzyme that breaks down the beta-lactam ring.
How do tetracyclines affect bacteria?
A broad-spectrum antibiotic that targets gram-positive and negative. they affect protein synthesis and inhibit the growth of bacteria.
How do fluoroquinolones affect bacteria?
Targets gram positive and negative bacteria and affects bacterial DNA replication by interfering with the enzymes DNA gyrase and topoisomerase IV.
How do Sulfa antibiotics (Sulfonamids) affect bacteria?
Targets gram-positive and negative bacteria and affects protein synthesis of vitamin B folate which prevents growth and reproduction.
What cellular components do some bacterial cells have that make them powerful pathogens?
The phil of a bacterial cell allows them to adhere to host cells which makes them stronger and is key in the initial infection.
Why are penicillins often more effective against Gram positive bacteria than Gram negative bacteria?
Gram positive bacteria have a thick layer of peptidoglycan that makes it easier for penicillin to access.
Why is it important to understand the structure of a bacterial cell when developing an antibiotic?
It makes it easier to identify specific targets within the cell that can be disrupted by the antibiotic, effectively killing the bacteria while minimizing harm to human cells.
How do antibiotics work without harming the surrounding human cells?
They affect things that are unique to bacteria, or target specific processes within bacteria.
Why are antibiotics NOT effective against viruses?
Viruses have different structures and a way of surviving than bacteria.
Antibiotic Resistant
Resistance to one or more antibiotics, usually due to additional genetic information.
Nucleoid
The DNA-containing area of a bacterial cell.
Plasmid (generic bacteria cell)
A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome.
Conjugation
The one-way transfer of DNA between bacteria in cellular contact.
Transformation
The process by which the genetic makeup of the call is changed by the uptake of DNA from the environment.
Transduction
The transfer of genetic material from one organism (such as a bacterium) to another by a genetic vector.
What is Streptococcus pneumonia and where is it found?
A gram-positive, lancet-shaped bacterium found in the back of the nose.
What diseases Streptococcus pneumonia can cause?
Ear infections, sinus infections, pneumonia, and meningitis.
What are some diseases that are considered antibiotic resistant?
Tuberculosis, malaria, skin infections, pneumonia, and ear infections.
Who received the 1945 Nobel Prize in Physiology and Medicine?
Alexander Fleming, Ernst Chain, and Howard Florey
What was the contribution of Dr. Norman Heatley?
Used available containers and bottles to grow Mass amounts of penicillin mold
What is the difference between Penicillium notatum and Penicillium chrysogenum?
The difference is just the name used to identify the species with “notatum” being considered outdated terminology.
What is the difference between E. Coli Strain I and E. Coli Strain II?
Strain 1 contains a gene found in the chromosomal DNA coding for streptomycin resistance. Strain 2 contains a gene found on the plasmid DNA coding for ampicillin resistance.
Where is the gene for streptomycin resistance found in a bacterium?
One the bacterial chromosome
Where is the gene for ampicillin resistance found in a bacterium?
On the Plasmid
Zone of Inhibition
The area around an antibiotic disc on an agar plate where bacterial growth is prevented, indicating the effectiveness of the antibiotic against the bacteria tested.
Ribosomes (generic bacteria cell)
the primary site for protein synthesis, translating the genetic code from messenger RNA (mRNA) into amino acids chains to build proteins essential for cell survival
Phil (generic bacteria cell)
Allows for bacteria to attach to specific surfaces or other cells, acting as adhesion
Capsule (generic bacteria cell)
a protective layer surrounding the cell by shielding it from the host immune system, allowing it to adhere to surfaces, and protecting it from drying out
Cell Wall (generic bacteria cell)
provides structural support and protection to the cell wall by maintaining it’s shape resistaining internal osmotic pressure, and acts as a barrier against external environmental factors
Plasma Membrane (generic bacteria cell)
a selective barrier controlling what substances can enter and exit the cell by regulation. The transport of nutrients in and waste products out, while producing that cells internal environment and maintaining its structural integrity.
Flagella (generic bacteria cell)
provides motility, allowing bacteria to move through liquid environments moving towards the cells favorable conditions such as nutrients and away from harmful substances
Exotoxins (generic bacteria cell)
proteins that alter the physiology of host cells, they are responding to things such as inflammatory responses, cellular signaling, and receptor mediated cytosis.
What color does gram positive bacteria stain?
Purple
What color does gram negative bacteria stain?
Pink
What are the main differences between Gram positive and gram negative cell walls
Gram Positive has a thicker peptidoglycan layer compared to gram negative cell walls but gram negative cell walls have an extra outer membrane that contain a porin.
1.2.2 Procedure “Which Antibiotic is Best” Lab (7 Steps)
Day 1:
1. Flame test tubes (cap and opening)
2. remove 250 ul with a pipette and place in the middle of an agar plate
3. Spread with L-spread
4. Incubate at 37 Celsius and incubate for 30 minutes
5. After, Use sterile forceps and place control disk in the middle of plate and then repeatedly with other antibiotic discs surrounding the control
6. Incubate at 37 Celsius
Day 2:
7. Sharpie sections of zone of inhibition
Why is the clear area surrounding an antibiotic disk called the zone of inhibition?
It indicates a region where bacterial growth
How do you analyze if an antibiotic worked better or worse against a specific bacteria?
Measure the zone of inhibition
What was the purpose of the control disk?
To make sure that bacteria was properly spread during our first steps of the lab
1.2.3 Lab Day 1 Purpose
To confirm the correct bacteria was sent and is what we expect the correct resistance to be and to find out of the bacteria is alive or not
1.2.3 Lab Day 2 Purpose
To create a new strain that is resistant to both amp, and strep by mixing (conjugation)
1.2.3 Lab Day 3 Purpose
To confirm conjugation occurrence (new strain)
1.2.3 Lab Day 1 Results
LB Agar Plate: SHow if bacteria is alive and if agar is good
LB Agar+Strep Plate: Strain 1 will grow because it is strep resistant and Strain 2 will not grow because it is not resistant and will kill it
LB Agar+Amp Plate: Strain 1 will not grow because the amp will kill it because it is not resistant and Strain 2 will grow because it is amp resistant and fights off the antibiotic
LB Agar+Strep+Amp: Both strains will not grow because both antibiotics will kill the bacterias
1.2.3 Lab Day 2 Results
Observing mix plate for possibilities of either a:
New strain (if conjugation occurred)
Strain 1/2: if conjugation did not occur
1.2.3 Lab Day 3 Results
LB Strep Plate: Growth of either new strain (if conjugation occurred) and strain 1 because of its resistance
LB Amp Plate: Growth of possible new strain (if conjugation occurred) and strain 2 because of its resistance
LB Strep+Amp Plate: Growth of new strain which means conjugation did occur
Genetic Mutation
A permanent change in the DNA sequence of a gene
Destruction/ inactivation
A process that can refer to the breakdown of antimicrobials, the termination of bacterial growth, or the elimination of microbial organisms
Efflux
The flowing out of a particular substance or particle.
What is the most common cause of antibiotic resistance?
Overuse and Misuse of antibiotics
what other variables, besides missing doses, might affect the success of an antibiotic?
If the bacteria is resistant to the antibiotic then the antibiotic would not work and the bacteria will continue to spread.
