micropara Flashcards
is the study of living organisms.
Biology
is an advanced biology course.
Microbiology
Living microbes are known as
cellular microbes or
microorganisms
Nonliving microbes are known as
acellular microbes or
infectious particles
The microbes that cause
disease are sometimes
referred to as
“germs.”
The scientific term for
disease-causing microbes
is
pathogens.
Microbes that live on and in our bodies are referred to
as our
indigenous microbiota.
are microbes that can cause
disease, but usually do not; they can be thought of as
microbes that are awaiting the opportunity to cause
disease.
Opportunistic pathogens
Pathogens cause two categories of diseases:
infectious diseases and microbial intoxications.
and produce much of the oxygen in our
atmosphere.
Photosynthetic algae, bacteria (such as
cyanobacteria)
are organisms that live on dead and/or
decaying organic matter.
Saprophytes
The use of microbes to clean up toxic wastes and
other industrial waste products is known as
bioremediation.
Candidates for the first microorganisms on Earth are
archaea and cyanobacteria
“Father of Microbiology”
Anton van Leeuwenhoek
Made many simple
single-lens microscopes
Anton van Leeuwenhoek
who Observed “animalcules”
(bacteria and protozoa)
Anton van Leeuwenhoek
French chemist who made
numerous contributions to
microbiology
Louis Pasteur (1822–1895)
Investigated different
fermentation products
Louis Pasteur (1822–1895)
Developed the
pasteurization process
Louis Pasteur (1822–1895)
Discovered life forms that
could exist without oxygen
(anaerobes)
Louis Pasteur (1822–1895)
Developed several vaccines,
including rabies and
anthrax vaccines
Louis Pasteur (1822–1895)
German physician who made
numerous contributions to
microbiology
Robert Koch (1843–1910
Made significant contributions
to the germ theory of disease
Robert Koch (1843–1910
Discovered that Bacillus
anthracis produced spores
Robert Koch (1843–1910
Developed methods of fixing
and staining bacteria
Robert Koch (1843–1910
Developed methods to
cultivate bacteria
Robert Koch (1843–1910
are used to express the sizes of microbes.
Metric units
The basic unit of length in the metric system is the meter
(m); it is equivalent to
39.4 inches
The sizes of bacteria and protozoa are usually expressed
in terms of
micrometers (μm).
Most of the viruses that cause human diseases range in
size from
10 to 300 nm.
When using a microscope, the sizes of microorganisms
are measured using an
ocular micrometer.
Each optical instrument has a limit as to what can be
seen using that instrument; this limit is referred to as the
resolving power or resolution of the instrument.
The resolving power of the unaided human eye is
approximately
0.2 mm.
is one that contains only one
magnifying lens.
A simple microscope
contains more than one
magnifying lens.
A compound microscope
Because visible light is the source of illumination, a
compound microscope is also referred to as a
compound
light microscope.
Compound light microscopes usually magnify objects
about
1,000 times.
Photographs taken through the lens system of the
compound light microscope are called
photomicrographs.
Other types of compound microscopes include
– Phase-contrast microscopes
– Fluorescence microscopes
are used to observe
unstained living microorganisms.
Phase-contrast microscopes
contain a built-in ultraviolet
(UV) light source.
Fluorescence microscopes
enable us to see extremely small
microbes such as rabies and smallpox viruses.
Electron microscopes
Living organisms cannot be observed using —the processing procedures kill the
organisms.
an electron
microscope
There are two types of electron microscopes—
transmission and scanning.
This microscope uses an
electron gun to fire a beam of
electrons through an extremely
thin specimen (<1 μm thick).
Transmission Electron Microscope
Magnification is approximately
1,000 times greater than with
the compound light microscope.
Transmission Electron Microscope
Electrons are bounced off the
surface of a specimen and the
image appears on a monitor.
Scanning Electron Microscope
This is used to observe the outer
surfaces of specimens.
Scanning Electron Microscope
Resolving power of this
microscope is about 100 times
less than that of transmission
electron microscope.
Scanning Electron Microscope
this micrographs are black-
and-white images.
Transmission and scanning
electron
A true nucleus consists of
nucleoplasm, chromosomes, and a nuclear
membrane.
Chromosomes are embedded in the
nucleoplasm.
An organism’s
complete collection of genes is referred to as its
genotype or genome.
Human diploid cells have
46 chromosomes (23 pairs).
It has been estimated that the human genome consists
of between
20,000 and 25,000 genes.
Contains storage
granules and a variety
of organelles
Cytoplasm
is where
most metabolic
reactions occur
Cytoplasm
A highly convoluted
system of membranes
arranged to form a
transport network in the
cytoplasm
Endoplasmic reticulum (ER)
The sites of protein
synthesis
Ribosomes
Originate in the Golgi
complex
Lysosomes and peroxisomes
are
membrane-bound
vesicles where H2O2 is
generated and broken
down
Peroxisomes
are
produced within
mitochondria by cellular
respiration
ATP molecules
Membrane-bound
structures containing
photosynthetic pigments
Plastids
They are sites of
photosynthesis
Plastids
Some eukaryotic cells (e.g., spermatozoa and certain
protozoa) possess long, thin, whiplike organelles of
locomotion called
flagella
Some cells move by means of , which are
shorter, thinner, and more numerous than flagella,
and described as being “hair-like.”
of cilia
Prokaryotic cells are about _ times smaller than
eukaryotic cells.
10
Main constituent of most bacterial cell walls is
)____ (found only in bacteria).
peptidoglycan
Gram-positive bacteria have a ____ layer of
peptidoglycan
thick
Gram-negative bacteria have a much
___ layer
thinner
Mycoplasma spp. do not have a cell wall; they are
pleomorphic.
Peritrichous bacteria
flagella over entire surface
Lophotrichous bacteria
tuft of flagella at one end
Amphitrichous bacteria
one or more flagella at
both ends
Monotrichous bacteria
single polar flagellum
They are hairlike structures, most often observed on
Gram-negative bacteria
Fimbriae and Pili
are thinner than flagella, have a
rigid structure, and are not associated with motility
Fimbriae and pili
The process of spore formation is called —it is
not reproduction
sporulation
Endospores can be visualized using a
spore stain
is the science of classification of living
organisms
Taxonomy
Taxonomy consists of
classification, nomenclature, and
identification.
KDCOFGS
K for Kingdom, D for Division, C for
Class, O for Order, F for Family, G for Genus, and S
for species.
The Five-Kingdom System of Classification
- Bacteria and archaea—Kingdom Prokaryotae
- Algae and protozoa—Kingdom Protista
- Fungi—Kingdom Fungi
- Plants—Kingdom Plantae
- Animals—Kingdom Animalia
The Three-Domain System of Classification
- Archaea (prokaryotic)
- Bacteria (prokaryotic)
- Eucarya (all eukaryotic organisms)
