BIOL 200 Exam 3 VOCAB PLUS

replication

DNA -> DNA x2

transcription

DNA -> DNA + RNA

reverse transcription

RNA -> DNA + RNA

reverse transcriptase is the enzyme that performs this process

translation

mRNA -> mRNA + protein

conjugation

transfer DNA through direct contact using conjugation pilus

transduction

horizontal gene transfer in bacteria where genes are transferred through viral infection

transformation

horizontal gene transfer where naked environmental DNA is taken up by a bacterial cell

transposition

process where DNA independently excises from one location in a DNA molecule and integrates elsewhere

genetic engineering

direct alteration of an organism's genetics to achieve desirable traits

recombinant DNA

artificial recombination of DNA from 2 organisms

transgenic organisms

organism where DNA from a different species has been introduced

restriction enzyme

bacterial enzyme that cuts DNA fragments at a unique recognition site

used in genetic engineering for splicing DNA fragments together into recombinant molecules

recognition sites

a specific DNA sequence recognized by a restriction enzyme that's typically 4-6 base pairs long and reads in the 5' to 3' direction

ligases

enzyme that joins 2 molecules together, important for linking pieces of DNA during replication and repair

transfection

introduction of recombinant DNA molecules into eukaryotic hosts

electrophoresis

lab technique used to separate DNA, RNA, or proteins based on their size and electrical charge, allows for visualization to compare genetic material

polymerase chain reaction (PCR)

in vitro molecular technique that rapidly amplifies the number of copies of specific DNA sequences to make amplified DNA available for analysis

PCR steps

1. the DNA is heated so the 2 stands separate (denaturation)

2. the mixture is cooled so primers can attach to the target sequence (annealing)

3. DNA polymerase builds new strands, doubling the amount of DNA (elongation/extension)

RT-PCR (real time)

variant of PCR that uses fluorescence to allow for monitoring of increase in double-stranded template during PCR reaction as it occurs

RT-PCR (reverse transcriptase)

variant of PCR used to obtain DNA copies of a specific mRNA molecule that begins with the conversion of mRNA to cDNA by the enzyme reverse transcriptase

DNA sequencing

method used to read the exact order of the bases in DNA

gene therapy

form of treatment for diseases that result from genetic mutations, involves introduction of nonmutated functional genes into the genome of the patient often using a viral vector

what is the role of primers in PCR?

they are short DNA sequences that bind to specific regions and define where DNA synthesis begins

3 multiple choice options

why is Taq polymerase (from bacterium Thermus aquaticus) used in PCR instead of regular DNA polymerase from E.coli?

Taq polymerase is heat-stable and won't denature at high temperatures

3 multiple choice options

what is the primary purpose of the PCR technique

to amplify a specific DNA segment

3 multiple choice options

if you start with 1 DNA molecule and run 25 cycles of PCR, approximately how may copies of that DNA segment will you have?

33 million copies

3 multiple choice options

PCR requires three main temperature steps that repeat in cycles. What happens during the denaturation step (around 94-95 degrees C)?

the double-stranded DNA separates into 2 single strands

3 multiple choice options

disinfectants

chemical products that reduces or destroys microbes on an inanimate item, ex; chlorine bleach, phenols, glutaraldehyde

antisepctics

chemicals like boric acid, hydrogen peroxide, iodine, and isopropyl that reduces microbial load on skin or tissue

sterilization

completely eliminates cells, endospores, and viruses, can use pressurized steam (autoclave), chemicals, or radiation and is often used when preparing surgical equipment

formites

inanimate objects that may harbor microbes and aid in disease transmission

BSLs

biological safety levels

BSL-1

low-risk microbes, not known to cause disease

BSL-4

high-risk microbes, frequently lethal without treatment or vaccines

aseptic

sterile state resulting from proper use of microbial control protocols

degermination

reduces microbial load on skin or tissue using soap or alcohol swab with gentle to firm scrubbing

-cidal

kills microbes

-static

stops microbial growth but doesn't kill

pasteurization

form of microbial control using heat that is applied to foods; kills pathogens and reduces the number of spoilage-causing microbes while maintaining food quality

which of the following best describes a microbial control protocol that inhibits the growth of molds and yeasts?

fungistatic

3 multiple choice options

which biosafety level is LEAST hazardous?

BSL-1

3 multiple choice options

pasteurization is best described as:

heating food to reduce microbial numbers

3 multiple choice options

what does the suffix "-cidal" mean?

kills microbes

3 multiple choice options

what does the suffix "-static" mean?

stops microbial growth but does not kill

3 multiple choice options

why are antibacterial drugs often more selectively toxic than antifungal or antiviral drugs?

bacterial cells contain peptidoglycan and 70S ribosomes, which differ from human cell structures

3 multiple choice options

which factor can accelerate the evolution of antimicrobial resistance

sub-therapeutic dosing

3 multiple choice options

which route of administration generally produces the highest and most rapid plasma drug levels?

intravenous

3 multiple choice options

which of the following is a common mechanism of antimicrobial resistance?

enzymatic inactivation of the drug

3 multiple choice options

what is a major risk of using a broad-spectrum antimicrobial?

it may disrupt the normal microbiota and lead to superinfection

3 multiple choice options

chemotherapy

use of chemicals as therapy/treatment

penicillin

beta lactam rim, antimicrobial drug

selective toxicity

desirable amount of an antimicrobial drug that kills the targeted microbe while causing minimal to no harm to the patient

narrow spectrum

targets a specific subset of bacterial pathogens, best used when a pathogen has been identified

broad spectrum

targets a wide variety of bacterial pathogens, can be used for polymicrobic infections

drug concentration

must be high enough to kill the pathogen while not harming the patient

toxic concentration

point where an antimicrobial drug is harmful to the patient

minimum effective concentration

the minimum point of an antimicrobial drug required to kill the pathogen

therapeutic index

the range that the antimicrobial drug is enough to kill the pathogen while not harming the patient

superinfection

secondary infection that may develop as a result of a long-term, broad spectrum antimicrobial drug use

routes of administration

oral, intramuscular, intravenous

mechanisms of antibacterial drugs

cell wall, plasma membrane, ribosomes, DNA synthesis, metabolic pathways, RNA synthesis

anti-fungal

treat fungal infections, most common action is disturbing cell membrane

anti-helminthic

used to treat helminthic infections, disrupt helminthic and protozoan microtubule formation, block neuronal transmissions

anti-protozoan

increase cellular levels of reactive oxygen species, interfere with DNA replication, disrupt heme detoxification

anti-viral

inhibit viral entry, inhibit viral uncoating, inhibit nucleic acid biosynthesis, prevent viral release from infected cells

drug resistance

ability of a microbe to persist and grow in the presence of an antimicrobial drug, can be caused by overuse of subtherapeutic doses of antimicrobial drugs

mechanisms of drug resistance

efflux pump, blocked penetration, inactivation of enzymes, target modification

susceptibility

Kirby-Bauer disk diffusion test is a way to determine susceptibility of a microorganism to different antimicrobial drugs

zone of inhibition

clear zone around a disk of antimicrobial drug that indicates the microorganism couldn't grow that close to the antimicrobial drug

infection

microorganism enters a host and begins to multiply, some can cause disease

primary infection

initial infection produced by a pathogen

secondary infection

develops after a primary infection as a result of the primary infection compromising immune defenses or antibiotics, eliminating the protective microbiotia

signs of disease

are objective and can be measured

symptoms of disease

are subjective and are reported by the patient

noninfectious disease

caused by genetics and/or environment

infectious diseases

caused by pathogens

communicable diseases

disease that is transmissible between individuals

contagious diseases

diseases that are easily transmissible between individuals

non-communicable diseases

disease that isn't transmitted from one person to another, can be contracted via contact with animals or environmental reservoirs

nosocomial diseases

contracted in hospital settings

latrogenic diseases

direct result of a medical procedure

etiology

science of the causes of disease

pathogenicity

ability of a microbial agent to cause disease

disease

any condition where the normal structure or function of the body is damaged or impaired

acute disease

short-term disease, develops quickly

chronic disease

long-term, can last months or years

latent disease

goes into dormant non-replicative state after acute disease and can persist in this state for years, risks reactivation back into acute disease

incubation period

first stage of disease, pathogen begins multiplying in the host, signs and symptoms aren't observable

prodromal period

second stage of disease, pathogen continues to multiply in host, non-specific signs and symptoms become observable

period of illness

3rd period of disease, number of pathogens present in host are greatest, signs and symptoms are the most severe

period of decline

4th period of disease, during the number of pathogens in the host decreases, signs and symptoms also decrease

period of convalescence

5th stage, patient returns to normal function

Koch's postulates

series of guidelines used to identify the microorganism that causes a specific disease

virulence

organisms degree of pathogenicity

portals of entry and exit

eye, mouth, nose, ear, vagina, urethra, anus

infectious dose

minimum number of microbes needed to establish an infection in a host

exoenzymes

secreted outside the cell, enzymes that enhances the ability of microorganisms to invade host cells and deeper tissue

endotoxins

lipid A component of LPS gram-negative cell envelope

exotoxins

toxic proteins secreted outside of cell, causes adverse changes in host cells, secreted mostly by gram-positive bacteria but can also be secreted by gram-negative

enterotoxins

exotoxin that targets the intestinal tract, disrupts normal ion and water balance leading to fluid loss