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MCB2000 Exam 2
microbiology exam two definitions
110
Microbiology
Undergraduate 2
10/15/2011

Additional Microbiology Flashcards

 


 

Cards

Term
Chromosome
Definition
structure that carries hereditary info, contains genes
Term
Plasmid
Definition
small circular DNA molecule that replicates independently of chromosomes
Term
Gene
Definition
segment of DNA encoding a functional product
Term
Genome
Definition
one complete copy of the genetic info in a cell
Term
DNA
Definition
nucleic acid of genetic material in all cells and some viruses
Term
RNA
Definition
class of nucleic acids that comprises of mRNA, rRNA, and tRNA
Term
Ribosome
Definition
site of protein synthesis in a cell, composed of RNA and protein
Term
Replication
Definition
when the cell elongates and becomes 2 cells
Term
Transcription 
Definition
copying DNA in the form of RNA, leaving DNA unchanged; process of synthesizing RNA from a DNA template
Term
Central Dogma 
Definition
replication, transcription, and translation
Term
Translation
Definition
use of mRNA to make a protein
Term
mRNA
Definition

messenger RNA

directs incorporation of amino acids into proteins

Term
tRNA
Definition

transfer RNA

brings amino acids to the ribosomal site where they are incorporated into proteins

Term
rRNA
Definition

ribosomal RNA

froms ribosomes

Term
Operon
Definition

operator and promoter sites and the structure genes they control; 

put several genes under the same command;

not in human cells

Term
Lac Operon
Definition
required for transport and metabolism of lactose in e. coli
Term
Trp Operon
Definition
codes for components of tryptophan, not used when tryptophan is present
Term
Inducible Operon
Definition

early metabolite in the pathway;

causes activation of transcription of the genes encoding the enzymes;

STARTS TRANSCRIPTION

 

Term
Repressible Operon
Definition

excess quantities of the end product of the pathway;

leads to cessation of transcription;

ENDS TRANSCRIPTION

Term
Catabolic Repression
Definition
inhibition of the metabolism of alternate carbon sources by glucose
Term
Codon
Definition
sequence of 3 nucleiotides in mRNA that specifies the insertion of an amino acid into a polypeptide
Term
Anticodon
Definition
the 3 nucleiotides by which a tRNA recognizes an mRNA codon
Term
Ligase
Definition

enzyme that fuses together fragments (Okazaki fragments);

join together 2 large molecules by forming a new chemical bond

 

Term
Helicase
Definition

allows for relaxing/opening up of DNA at the replication fork, exposing the single strand;

enxyme that hydrolize ATP as they move ahead of the relication fork;

ATP dependent

Term
Okazaki Fragments
Definition
short molecules, single strand DNA, that are formed on the lagging strand of DNA replication
Term
Reverse Transcription
Definition

convert RNA into DNA;

only in viruses

Term
Replication Fork
Definition
the point where DNA strands separate and new strands are synthesized
Term
ORI
Definition

Origin of replication;

where replication always begins in DNA;

here, DNA bulges and creates 2 replication forks

Term
Bidirectional Replication
Definition

type of DNA replication; 

creates 2 replication forks moving in opposite directions

Term
Role of Radiation in Mutation
Definition

type of mutagen (cause mutation);

2 types: ionizing and non-ionizing;

increases frequency of mutations

Term
Mutagen
Definition
something in the environment that causes mutations
Term
Carcinogen
Definition
any cancer causing substance
Term
Ames Test
Definition

procedure using bacteria to identidy potential carcinogens;

looks for damage to bacterial DNA by looking for metabolic activity being affected by mutation/damage to DNA

Term
Recombinant DNA Technology
Definition

intentional modification of the genomes or organisms by natural and artificial processes for practical purposes;

 

Term
Tools for Recombinant DNA Technology
Definition

reverse transcriptase

restriction enzymes

vectors

gene libraries

Term
PCR
Definition

polymerase chain reaction;

technique using DNA polymerase to make multiple copies(large numbers) of a DNA template in vetro

Term
Gel Electrophoresis
Definition

separation of substances (DNA) by their rate of movement through an electrical field;

allows scientists to isolate DNA of interest

Term
Gene Library
Definition

collection of organisms that each contain a piece of the DNA from the host you are working with;

may contain all genes of a single chromosome

Term
Vector
Definition

nucleic acid molecules that carry DNA into a new host;

best vectors are small

 

Term
Examples of Vectors
Definition
plasmids, viruses, and transposons
Term
Prokaryote
Definition
cell whose genetic material is not enclosed in a nuclear envelope
Term
Eukaryote
Definition
cell having DNA inside a distinct membrane enclosed nucleus
Term
Monera
Definition

one of 5 kingdoms;

most organisms with a prokaryotic cell organization

Term
Eubacteria
Definition

one of 3 microorganism domains;

prokaryotic bacteria;

single cell

Term
Etiology
Definition
study of the cause of diseases
Term
Virus
Definition

single strand DNA or RNA;

submicroscopic, parasitic, filterable agent consisting of a nucleic acid surrounded by a protein coat;

use humans as a host

Term
Capsid
Definition
protein coat of a virus that surrounds the nucleic acid
Term
Spike
Definition

proteins that protrude/project from the lipid layer of viruses;

used for recognition and attachment to the host cell

Term
Envelope
Definition

outermost layer of viruses;

composed of lipids and viral proteins (spikes)

Term
Plaque Assay
Definition

used to quantify viruses/determine virus concentration;

(plaque = area on plate containing dead viruses)

the number of plaques relates to the number of infectious particles applied to the plate;

how viruses are counted

Term
Prion
Definition

piece of protein;

PrP;

infectious agent consisting of a self replicating protein with no detectable nucleic acids

Term
Virion
Definition
complete, fully developed viral particle
Term
Viroid
Definition
infectious RNA
Term
Monolayer
Definition

when growing viruses, done by taking tissue from liver or animal cell and spread on bottom of a flask;

tissue attaches to the bottom of the flask with addition of an adhesive substance (the monolayer)

Term
Tissue Culture
Definition

the growth of tissues;

cells separate from the organism

Term
Interferons
Definition

proteins released & produced by the immune system that attack viruses directly;

can kill viruses

Term
Uncoating
Definition

separation of viral nucleic acid from its protein coat;

capsid coat of virus peels off

Term
Viral Replication Cycle
Definition
formation of biological viruses during the infection process in the target host cells
Term
Zoonosis / Zoonotic Disease
Definition

disease that is transimitted from animals to human;

not usually transferred from human to human

Term
Icosahedron
Definition

the shape of a virus;

regular polyhefron with 20 identical equilateral triangular faces

Term
Nosocomial Infection
Definition

disease caught and transmitted in a hospital;

more prevalent in people that are older people, with weak immune systems, or require hospitalization

Term
Endotoxin
Definition

part of the structure of gram negative bacteria (outer portion);

released when bacteria is killed;

very dangerous/toxic;

lipopolysaccharides (LPS)

Term
Exotoxins
Definition

toxic chemicals produced & secreted by (gram positive) bacteria;

made from proteins;

 

 

Term
Enterotoxins
Definition

type of exotoxin that affects the digestive tract

(Ex: cholera - a water borne disease)

Term
Neurotoxins
Definition
type of exotoxin that affects the nerve cells
Term
Koch's Postulates
Definition

Robert Kock developed 4 postulates that must be used to prove a certain pathogen causes a certain disease.

1. Observation

2. Isolation

3. Re-infection

4. Re-observation

Term
Pathology
Definition
scientific study of disease
Term
Contamination
Definition
temporary presence of microorganisms in/on the body
Term
Infection
Definition
organism has invaded the body and has established itself in the body through multiplying and spreading itself
Term
Disease
Definition

abnormal condition or function;

results only if invading pathogen alters the normal functions of the body;

referred to as morbidity

Term
Reservoirs of Infection
Definition

places microorganisms are found on a normal basis;

source of infection

Term
Animate
Definition

showing characteristics of life;

living

Term
Inanimate
Definition

Not showing characteristics of life;

nonliving

Term
Carrier
Definition

humans or other animals in which the infectious agent is growing and reproducing with little or no visible harm to the current hose;

harbors pathogens and transmits them to others

Term
Chronic Carrier
Definition

people or animals that usually have had the disease and the infectious agent is still present within them;

acts as a host without displaying any signs of the disease

Term
Mode of Transmission
Definition
the way in which an infectious organism is spread
Term
Direct Contact Transmission
Definition

person to person or reservoir to person;

Ex: handshaking, kissing, sex;

Ex: common cold, tuberculosis, measles, chicken pox

Term
Indirect Contact Transmission
Definition

through a fomite (any inanimate object that can carry infectious organisms - germs/parasites)

Ex: towels, door knobs, pencils;

Ex: anthrax, respiratory virus, water borne and food borne disease

Term
Droplet Contact Transmission
Definition

not airborne;

exposure to liquid droplets from sneeze/cough of infecter person can spread cold or flu virus;

can travel meter or less;

form of indirect contact

Term
Vehicle Transmission
Definition

something that carries the organism into your body;

Ex: food and water

Term
Vector Transmission
Definition

insects that directly deposit organism under your skin;

Ex: flies, mosquitos, ticks, fleas;

Ex: bubonic plague, lyme disease, dengue fever, malaria

Term
Triangle of Infection
Definition
microbes, host, and environment
Term
Endemic
Definition

disease that is always present in the environment;

low frequency;

Ex: common cold

Term
Pandemic
Definition

spread of a disease throughout the world;

Ex: H1N1 flu virus

Term
Epidemic
Definition
spread of a disease within a country
Term
Mortality
Definition
death caused by disease
Term
Morbidity
Definition

disease;

condition of being diseased

Term
Superantigen
Definition

mimic a multiple attack of several different organisms simultaneously;

overactivation of the host immune system;

can cause stress on the organism

Term
Symbiosis
Definition

organisms living close together and interacting with each other;

 

Term
Parasitism
Definition

interaction where one organism feeds off the other and the otehr is harmed but not necessarily killed;

symbiotic relationship

Term
Mutualism
Definition

interaction of 2 organisms in which 2 organisms support and benefit each other;

symbiotic relationship

Term
Antagonism
Definition

interaction in which the parasite harms and kills the host;

symbiotic relationship

Term
Commensalism
Definition

interaction where one organism benefits and the other neither benefits or is harmed;

symbiotic relationship

Term
Mucins
Definition
heavily glycosylated proteins produced by epitheleal tissues in most metazoans
Term
Lysozyme
Definition

protein that kills the cell wall of bacteria;

present in bodily secretions (saliva)

Term
Lysosome
Definition
organelle containing digestive enzymes
Term
Phagocytosis
Definition
engulfment/ingestion of bacteria
Term
LD50
Definition

lethal dose;

number of microorganisms it takes to kill 50% pf the infected population

Term
ID50
Definition

infectious dose;

number of microorganisms it takes to make 50% of the population sick

Term
Routes/Portals of Entry
Definition

- skin

- mucous membranes (respiratory/GI tract)

- placenta (genital tract)

- parental route

*same as exit

Term
Portals of Exit
Definition

- skin

- mucous membranes (respiratory/GI tract)

- placenta (genital tract)

- parental route

*same as entry

Term
Parental Route
Definition

one of the routes of entry;

when the microorganism bypasses the normal protection/skin;

(ex: injection or cut)

Term
Normal Microbiota
Definition

microorganism that colonize a host without causing disease;

normal flora

Term
Normal Flora
Definition
natural population of microorganisms that live on the surface of the skin
Term
Virulent
Definition

microorganisms that are non-disease causing because of an inability to make attachment proteins or adhesions;

degree of pathogenicity of a microorganism

Term
Virulence
Definition

relative ability of bacteria to cause disease; 

how effective the bacteria are in making people sick

Term
Capsule
Definition

gel layer that covers and protects the bacteria against phagocytosis;

allows better attachment of bacteria to stick together in a biofilm

Term
Adhesion
Definition

protein that projects from prokaryotic walls; 

used for adherance (attachment of microbe/phagocyte to another's plasma membrane or other surface);

also called a Ligand

Term
Extracellular Bacteria
Definition

present in body, but not within cells;

Advantage: can easily spread through the body;

Disadvantage: constantly being hunted and tracked by immune system 

Term
Intracellular Bacteria
Definition

located within the cells;

Advantage: protected against immune system;

Disadvantage: confined within the cell

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