Download File - Science with mrs. munoz

Taxonomy, Viruses, and Bacteria
Fill-In Notes
• Taxonomy= Science of classification
• Carolus Linnaeus - Discovered our current
classification system-based on physical characteristics
• How to classify:
• Use phylogenetic branching trees to show evolutionary
relationships
• Use physical characteristics to group organisms
Levels of Organization:
Gray Wolf example
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Canis
Species: lupis
Can remember the levels with the sentence:
KING PHILLIP CAME OVER FOR GOOD SPAGHETTI
There are 6 kingdoms: Animalia, Plantae,
Fungi, Protista, Eubacteria, Archaebacteria
(Eu and Archaea used to be Kingdom
Monera and then it split)
Above the 6 kingdoms, there are 3 domains:
Bacteria, Archaea and Eukarya
Genus and species names are the two word
names we give to organisms = binomial
nomenclature (bi = two; nomial = name;
nomen = naming; cloture = system)
Ex: Homo sapiens, Escherichia coli,
Armadillidium vulgare
First word is Genus (is capitalized)
Second word is species (not capitalized)
BOTH are written in italics or underlined
Pathogen:
Agent that can cause disease
• General Characteristics of Viruses
• Not considered to be alive because
they are not cells and cannot perform
any functions on their own. They have
NO organelles and cannot use energy
to build PROTEINS.
• A virus MUST enter a host cell in order
to reproduce.
Virus Structure
Figure 1.1:
General virus structure
1.
All viruses have a capsid or head region that
contains its genetic material. The capsid is made
of proteins.
2. Some viruses have an envelope surrounding their
capsid. This allows viruses to penetrate host cells
through membrane fusion.
3. The virus's genetic material rests inside the capsid;
that material can be either DNA, RNA, or even in
some cases a limited number of enzymes. The type
of genetic material a virus contains is used in
classification as there are DNA viruses like herpes
and the RNA viruses like HIV and flu.
4. In addition to the head region, some viruses have a
tail region. The tail aids in binding to the surface of
the host cell and in the introduction of virus
genetic material to the host cell.
-Virus "Life" Cycles
• Figure1.2: Generalized Replication of Viruses
1. All viruses share 6 basic steps in their replication cycles.
These are: attachment, penetration, uncoating,
replication, assembly and release
2. Lytic phase –virus particles infect the cell and replicate
immediately
3. Lysogenic phase-viral genetic material enter the host cell,
become incorporated in the cell and lies dormant
(asleep). Gets passed on and reproduce and then will
bust out of the cell in the lytic cycle (herpes).
4. Smaller than viruses are viroids = cause disease in plants
= tobacco mosaic virus
5. Smaller than viroids are prions = made only of proteins
that can cause other proteins to fold the wrong way so
the protein does not function correctly.
6. List of viruses: cold, flu, herpes, HIV, Ebola, chickenpox,
measles, mumps, rabies, smallpox, yellow fever,
hepatitis
General Characteristics of Bacteria
• -Are prokaryotic cells
(pro- means NO nucleus)
• -Structure
Roles of Bacteria
a. Are cause of diseases.
b. Most are beneficial to other organisms.
c. Can be photoautotrophs = nitrogen fixing
bacteria making nitrogen available to the
roots of plants.
d. Other bacteria are saprophytes, breaking
down dead organic material.
e. Others live symbiotically in the digestive
tracts of other organisms to help with
digestion.
f. Reproduce by binary fission not mitosis. In
this process, the genetic material is
replicated, and the two copies move to
separate regions. Next, the plasma
membrane pinches inward, producing two
equal daughter cells. Takes place every 20
minutes.
g. List of bacteria: acne, strep throat, E. coli,
Salmonella, tuberculosis, syphilis, typhus,
tetanus, tooth decay, bubonic plague, some
types of pneumonia, bronchitis, good
bacteria in your intestines and on your skin,
helps make yogurt, pickles
Eubacteria Figure1.4: Common
shapes of eubacteria
• -Shape
• Eubacteria are often classified by their
shape. They fall into three main shape
categories.
• round = cocci;
• rod= bacilli;
• spiral =spirilla.
Archaebacteria
Characteristics
1. The name "archaebacteria," with its prefix
meaning "ancient," suggests that this is an
extremely old group but this is not the case.
2. The fact that most of these Monerans live in
extremely hostile, extreme environments like
deep in ocean, soil
3. Can be aerobic (oxygenated) conditions or
anaerobic (non-oxygenated) conditions or
facultative anaerobes (both conditions).
4. Have different types of proteins in their cell walls
to make them Gram + or Gram -
Vaccinations
Characteristics for vaccinations against BACTERIA.
1. Contains the pathogens or their toxins in a
harmless form.
2. Treated w/ chemicals or heat, or genetically
engineered
3. Dead bacteria cannot cause disease
4. Stimulate immune system to defend against the
bacteria
Ex: DPT shot (diphtheria, pertussis and tetanus)
Characteristics for vaccinations
against VIRUSES.
1. Contains viruses made harmless by treatment
w/ chemicals or by genetic engineering
2. Stimulates immune system to create defenses
against the harmful form of a virus
3. Vaccination only works when the proteins on the
virus don’t change
Ex: smallpox, chickenpox, measles, and polio
virus – same surface protein each generation
Ex: HIV, cold viruses, flu viruses have surface
proteins that change vaccine for an old coat
would not recognize a new coat
HIV changes the most rapidly
Antibiotics
• Characteristics
• Antibiotics are antibacterial drugs…
do NOT work on viruses
• Examples: Penicillin, tetracycline, and
streptomycin
• May prevent bacteria from making cell walls
• Definitely over prescribed
• Our immune system can fight off some of the
lesser bacterial infections (given time!)
-Super Bacteria
(ex: MRSA= super staph infection)
• Resistant to antibiotics
• Mutations occur randomly
• Get variations of bacteria that can
resist an antibiotic
• Failure to take antibiotics as
prescribed
• Weak bacteria are killed first,
stronger bacteria survive