CH 1 Flashcards
pathogen
agent of disease; among professionals, pathogens typically are limited to bacteria, viruses, and fungi
microbe
living organism that requires a microscope to be seen
cell
smallest unit of life
genome
complete genetic content of an organism
prokaryote
an organism whose cells lack a nucleus. bacteria, archaea
eukaryotes
cells with a nucleus. fungi, protozoa, algae
extremophiles
live in seemingly hostile environments
most extremophiles are part of what group?
archaea
do archaea cause disease?
none have been found to cause disease. (no pathogenesis)
motile
able to move
heterotrophs
consumes organic food
protists
algae and protozoa
fungi
heterotrophic organisms, usually nonmotile and grow by absorbing nutrients from their surroundings.
has cell walls
yeast
single celled fungi
bread mold
multi celled fungi
mushrooms
complex fungi structure
helminths
eukaryotic microbial pathogens. are parasites, live at the expense of a host they inhabit, debilitating the host. multicellular
viruses
non-cellular microbes. contains genetic material that takes over the metabolism of a cell to generate more virus particles.
may be enclosed in a lipid envelope
species
a type of organism classified according to a shared set of genes and traits
strains
genetic variants of a species
viroids
infectious RNA (no proteins)
prions
infectious proteins (no RNA or DNA)
protozoa
eukaryotic single celled microbe, typically consume organics (some use photosynthesis), NO cells walls, often motile
some are pathogens
algae
photosynthetic eukaryotes, cell walls, some are motile, both uni and multi cellular.
not pathogenic, but can produce toxins in the environment
bacteria
singe-celled(mostly) prokaryotic microbe, cells walls made of peptidoglycan, motile, organic/inorganic food, some use photosynthesis, some are pathogens, some are extremophiles
archaea
single celled prokaryote, has cell walls, some are motile, organic/inorganic compounds for food
microbiology
the study of microscopic organisms, such as bacteria, viruses, archaea, fungi and potozoa
3 different kinds of microbes
bacteria, archaea, eukarya (protozoa, algae, fungi)
species
type of organism classified according to a shared set of genes and traits
strains
genetic variants of a speices (ex. Escherichia coli K12 Escherichia coli O157:H7)
Bacteria traits
single-celled
cell walls made of peptidoglycan
some are motile (flagella/pili)
use organic/inorganic compounds for food, some use photosynthesis
some are pathogens
some are extremophiles
archaea
single-celled
similar to bacteria in size and shape
cell walls
some are motile (flagella)
use organic/inorganic compounds for fod
many extremophiles
none known to cause disease
protozoa
usually single-celled
most aborb/ingest organics, a few photosnythesize
NO CELL WALLS
often motile (flagella, cilia, psuedopods)
many are free-living or some are parasitic and pathogenic
algae
PHOTOSYNTHETIC
cell walls
some are motile (flagella)
found in freshwater, saltwater, and soil
UNIcellular AND MULTIcelluar
can produce toxins in the environment (NOT pathogenic)
Fungi
cell walls
uptake organic compounds
unicellular (MOLDS) and multicellular (MUSHROOMS)
USUALLY NON-MOTILE
some are pathogens
mycology
study of fungi
helminth
MULTIcellular/macroscopic
flatworms and roundworms
human pathogens/parasites
microscopic during some early stages in their life cycle
viruses
DNA or RNA genome
protein capsid
may be encloped in a lipid envelope
inert outside living host
virology
study of viruses
viroids
infectious RNAs (no proteins)
prions
infectious proteins (no RNA/DNA)
10,000 BCE
Food/drink were known to ferment to produce alcohols/vingear
1500 BCE
evidence of microbial diseases in human mummies and art such as polio, smallpox, leprosy
1000 CE
rudimentary smallpox immunizations
1025 CE
diseases understood to be contagious, dont know why
1300-1400 CE
bubonic plague
Robert Hooke
developed first compound microscope and observed biological materials he called “cells”. published his findings in MICROGRAPHIA (1665)
Did robert hooke actually see cells?
No, his microscope was not strong enough to observe single-celled organisms
Antonie van Leeuwenhoek
first individual to observe single-celled microbes using single lens magnifier.
“father of microbiology”
noted disappearance of microbes from his teeth after drinking a hot bev - suggested that heat kills microbes
spontaneous generation
the idea that microbes arise spontaneously
Lazzaro Spallanzani
YEAR 1765
steralized sealed flask of meat = no bacterial growth
observed microbes in pairs - observed a single microbe split in two - cell fission
discovered biogenesis
biogenesis
the idea that living material only arises from other living material
did Spallanzani disprove spontaneous generation for the masses?
No, many argued that oxygen was required for spontaneous generation to take place, and the meat did not grow microbes because it was sealed.
Louis Pasteur (Mid 1800s)
designed a new flash that allowed air but caught dust and microbes in the S curve. concluded spon. gen. doesn’t exist and that microbes contaminate
John Tyndall (mid-late 1800s)
performed same experiment as Pasteur but sometimes found growth due to the organic matter being contaminated with endospores
endospores
heat resistant form of bacteria
can endospores be killed?
yes, by using high heat and pressure (autoclave)
the golden age of microbiology
mid-1800s-1910s
Three keys in the Golden Age of Microbiology
1) early techniques for classifying and identifying microbes
2) relationship between microbes and disease discovered
3) microbes found to be metabolically diverse
Germ Theory of Disease (1800s)
specific diseases are causesd by specific microbes
Miasma “bad air” theory
competing theory to germ theory of disease that air was bad
Florence Nightingale
first to use medical statistics to demonstrate the significance of mortality due to disease
Ignaz Semmelweis
Observed infections in women after birth
Hypothesized that doctors in his hospital were transmitting pathogens
Made them wash their hands in antiseptics
Jon Snow
Collecting information can describe the spread of disease (?)
Robert Koch
discovered “Chain of infection” of transmission of a disease
Koch’s postulates
specific method or criteria used to determine if a specific organism causes a specific disease
techniques for iolsating bacteria
pure cultures grown from a single colony of baceteria
gram-staining
small pox variolation (1000 BCE)
first type of immunization, exposure to lesions of the diseased with smallpox. dangerous because could still lead to people getting very sick
Edward Jenner (1796)
Used cowpox instead of smallpox to inoculate patients, dubbed vaccination
Louis Pasteur (again!) (1870s)
recognized the significance of exposure to weakened (attenuated) strains of bacteria, conferred immunity to a disease without causing severe symptoms
Joseph Lister
used chemical treatment of surgical instruments to prevent transmission
Alexander Fleming (1929)
discovers Penicillin (1929) as the first natural anti microbial drug
Paul Ehrlich (1909-1910)
identified a chemical anti microbial drug (Salvarsan to treat syphilis), also had the theory of immunity that our bodies make compounds to fight pathogens (antibodies)
lithotrophy
bacteria can oxidize iron and sulfur
Sergei Winogradsky
studied microbes in their natural habitats. developed media to grow somem icrobes while excluding others
discovered bacteria (lithotrophs) can use inorganic molecules
microbes are critical for
cycling inorganic and organic forms of N, S, P, etc.
Carbox fixation and O2 generation
microbes are Primary Producers
production of chemical energy in organic compounds by living organisms
microbes help do what in their environment
filter water
endosymbionts
an organism that lives inside other organisms (bacteria serve as endosymbionts for animals and plants)
human microbiota
community of microorganisms in/on the human body
benefits of human microbiota
digestion, immune system development, growth factors (vitamin B & K), resistance (prevents growth of pathogens through competition)
microbes are model systems
Because of their comparative simplicity, microbes are ideal models for studying many fundamental aspects of molecular biology
understanding DNA structure in the 1950s led to the development of
DNA sequencing in the 1960s
DNA sequencing
determining the exact sequence of nucleotides, or bases, in a DNA molecule.
Carl Woese (1970s)
proposed the 3 domains of life structure (baceria, archaea, eukaroyte) based on Ribosomal RNA sequence
metagenomics
high-throughput sequencing of a microbial community
other molecular techniques for genome sequencing
viral vecotrs (gene therapy)
CRISPR (edit genomes)
