Unit 10 Bacteria, Viruses &...
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Transcript of Unit 10 Bacteria, Viruses &...
Unit 10
Bacteria,
Viruses &
Disease
KINGDOMS:Eubacteria
AND
Archaebacteria
REVIEW… Cladogram of Domains
Which is the oldest domain in this cladogram?• Domain Bacteria
Pathology
Is defined as the scientific study of the nature
of disease and its causes, processes,
development, and consequences.
A pathogen is a disease causing agent, such
as bacteria, viruses, fungi or parasites.
Prokaryotic cell characteristics
• Free floating genetic materialinside cell
• Cell body enclosed by cell wall
• Small, unicellular organism
• DOES NOT contain specialized membrane bound organelles(lacks nucleus)
• Until recently, bacteria were placed into one Kingdom. As a result, sometimes bacteria are referred to as Monerans.
Kingdom Eubacteria & Archaebacteria
Eubacteria (True Bacteria)
Tend to be smaller
Found throughout the environment
Can be pathogenic
Classified according to their mode of getting nutrients,
mechanism of movement, and their shape
Archaebacteria (Ancient Bacteria)
Tend to be larger
Thought to be ancestors of eukaryotes, gene sequences are
similar.
Tend to live in extreme environments – sometimes they are
called “Extremophiles”
Archaebacteria
Halophiles – Live in very salty environments;
Great Salt Lake
Acidophiles- live in areas of low pH level
(acidic)
Thermophiles – live in high temperatures
Ex: Thermoacidophiles – sulfur hot springs;
hydrothermal vents found deep in the oceans
Methanogens – cannot live in the presence of
oxygen; sewage treatment plants, swamps, bogs
Diversity: Interaction with Oxygen
Obligate Aerobes - require oxygen for
cellular respiration, need oxygen to make ATP
energy for growing and surviving
Obligate Anaerobes - must avoid oxygen,
they will die in its presence
Facultative Anaerobes - can live with or
without oxygen
Diversity: Metabolic (energy usage)
Heterotrophs- get energy by consuming organic
compounds made by other organisms (eat)
Chemoheterotrophs- an organism that gets
“nourishment from others and from using chemicals”
Ex. Lactobacillus “good” bacteria found in yogurt
Photoheterotrophs- an organism that gets
“nourishment from others and from using light”
Ex. Cyanobacteria (makes up pioneer lichens)
Diversity: Metabolic
Autotrophs- make their own food from
inorganic molecules
Chemoautotrophs- an organism that makes
energy for itself using inorganic material such
as sulfur or iron
Ex. archaea living in hostile environments such
as deep sea vents
Photoautotrophs- an organism that gets
“nourishment for itself using light and CO2”
Identification: Diversity of Bacteria Naming
□Cocci – sphere
□Bacilli – rods
□Spirilla – spirals
Prefixes:
□Diplo – in pairs
□Staph – in
clusters
□Strep – in chains
Diversity: Structural Adaptations to Survive Hostile
Environments
Capsules (slime layers) - help evade immune
system and adhere to surfaces
Pili – hair-like projections
Endospores – dormant, tough outer structure for
protection until conditions become favorable
Flagella - one or more long tail-like structures
Diversity: Gram Stain
Stains used to identify bacteria based chemical
differences in their cell walls.
Bacterial species with walls containing small amounts
of peptidoglycan are Gram-negative and turns pink.
Bacteria with walls containing relatively large
amounts of peptidoglycan are Gram- positive and
turns purple.
Gram-Negative & Gram-Positive
Reproduction: Binary Fission
One cell splits into two
cells (asexual)
Offspring are
genetically identical to
parent
Quick, fast reproduction
time
Reproduction: Conjugation
Sexual reproduction
with exchange of
genetic information
before dividing
Offspring have new
genes genetically
different to parents
Increase diversity
Bacteria: Friend or Foe?
Lactobacillus
acidophilus turns
milk into yogurt.
Escherichia coli live
in your gut and
help you digest
food.
Friend: Helpful Bacteria
1. Decomposers – recycles dead organisms/nutrients
to soil
2. Help digest food as well as produce vitamins
3. Nitrogen-fixing bacteria: transforms
atmospheric nitrogen and allows it to be absorbed
by plant nodules for growth (proteins)
4. Food – helps ferments milk, cheese, yogurt
5. Clean oil spills (purify water)
6. Antibiotics – bacteria fighting bacteria
Foe: Harmful Bacteria
How do bacteria cause disease?
a) By breaking down the cells and tissue for food
Ex: Mycobacterium tuberculosis (tuberculosis), tooth
decay/cavities
b) Releasing toxins that can move through the body
Ex: Streptococcus- strep throat
Ex: Borelia burgdorferi- Lyme disease
c) Spores are formed and inhaled, can be fatal
Ex. Bacillus anthracis- Anthrax
Found in sheep and cattle
Controlling Bacterial Growth1. Freezing: stops growth
for most bacteria
2. Refrigeration:
-Slows growth / takes
longer to multiply
-Does not kill bacteria
3. Canning/ Jarring:
-Heat & seals out air
-Some endospores may
still survive
Controlling Bacterial Growth
4. Cooking:
High temperature
kills bacteria
5. Drying: no moisture/ dehydrate
6. Salting: if enough will kill bacteria
due to placing cells in osmotic
hypertonic environment
B. Controlling Bacterial Growth
7. Sterilization:
-Using high temperatures for long periods
Autoclave (High heat and pressure)
-Chemical action
8. Disinfectant:
-Chemical solutions ex. alcohol
- Used to clean surfaces
Virus = Virion
1. Living characteristics of viruses: They contain genetic material (DNA or RNA) never both!!
2. Nonliving characteristics of viruses They are acellular / not cells (they contain no cytoplasm
or organelles).
They do not metabolize energy
ONLY replicate using the host cell's machinery.
They do not grow and divide. Instead, new viral components (proteins) are synthesized and assembled within the infected host cell.
They are NOT alive!!!
Structure of a Virus
A virus particle, or virion, consists of the following:
a. Nucleic acid - set of genetic instructions, either DNA
or RNA
b. Coat of protein (capsid) - surrounds the DNA or RNA
to protect it
c. Lipid membrane aka envelope- surrounds the protein
coat (found only in some viruses such as influenza/flu
virus)
Specificity: To Host Cells
Viruses are specific to their hosts.
□ Virus have surface proteins that
can only match to exact receptor
sites on a host cell like a lock & key
Ex. Rabies virus only attacks brain cells
Ex. HIV only attacks helper T-cell in the
immune system
Ex. Influenza only attacks cells of the
respiratory track
Virus A will attack which cell?
Bacteriophage
Viruses that infect ONLY bacteria.
Have a protein "tail" attached to the capsid
(protein coat that envelopes the genetic
material), which is
used to infect the
host bacteria.
Viruses cannot
reproduce on their
own, and must infect
a host cell in order
to create more
viruses.
Replication
Use their own genetic material and the host cell's machinery
1. Penetration - surface proteins bind to host, and release genetic material
(RNA or DNA) into the cytoplasm
2. Replication - the viral genetic material is copied
3. Transcription - the genetic material is used as a blueprint, for the cell to
make messenger RNA which is used to make viral proteins
4. Protein Synthesis – translation occurs in the cytoplasm (ribosomes), viral
proteins are made
5. Viral Assembly - the viral genetic material (from replication) is
surrounded by the newly made viral proteins
6. Release - viruses emerge from the cell by "budding" from the cell
membrane or bursting out of the cell (this causes the cell's death)
Lytic and Lysogenic Pathways
Lytic Pathway :
a. Rapid replication of the virus, ending in cell lysis (bursting of host).
b. More phages are released to infect other cells.
c. Effects of illness are immediate- within hours/days
Lysogenic Pathway:
a. The virus integrates DNA into host’s DNA becoming a prophage
b. Stays inactive within the cell and is copied when cells reproduce **no illness or symptoms for months/years
c. Changes in environment or health of host can trigger the prophage to activate in lytic cycle
HELP me from viruses!
A vaccine can be used to prevent a viral disease.
A vaccine can help your immunesystem become stronger and respond faster with viral recognition.
Vaccines prevent the virus from attaching to a host cell
Antibiotics will NOT work against viruses.
HIV (causes AIDS) Transmission (spread
by)
Bodily fluid exchange
No cure / No vaccine
HIV damages Helper T cells in the immune system
Without T cells body cannot fight other infections (bacterium, flu virus) and your body is left with no immune defense
Other examples of Viruses
Cold
Zika
West Nile
Herpes
Warts
Polio
Measles
Chicken pox
Oncogenic Virus: virus that can
cause cancer (HPV)
Describe the effects of
antibodies on viruses.
Antibodies will ____________
Unit 6 – Protists
Remember this chart?????
Compare
Genetic
material
Structure Obtain
energy?
Living?
Prokaryotes DNA and
RNA
Unicellular,
simple
YES YES
Eukaryotes DNA and
RNA
unicellular or
multicellular,
complex
YES YES
Viruses DNA or RNA
not both
(nucleic acid)
No cells:
Protein,
nucleic acid
NO NO
I. The Kingdom Protista
Protist characteristics
Eukaryotic – have a nucleus, membrane
bound organelles
Found in fresh water & ocean water
Most are unicellular, some are multicellular
Some have chloroplasts and cell wall made
of cellulose
Most are heterotrophic, some autotrophic
Protista is the Greek word for “the very first”
II. Classification of Protists
Protists are categorized according to
how they obtain energy
Heterotroph
Autotroph
Decomposer
II. Classification of Protists
3 main groups of protists (how they obtain
energy)
1. Animal-like (heterotrophs)
2. Plant-like (autotrophs)
3. Fungus-like (decomposers)
III. Animal-like Protists
(AKA: protozoans)
Classified by locomotion (how they move)
1. Flagella – whip-like tail
III. Examples of Animal-like
Protists that move with flagella
Trichonympha – lives in
gut of a termite and
helps digest wood
Giardia –-causes diarrhea if you
don’t boil or treat water
III. Animal-like Protists
2. Cilia - Short hair-like projections
III. Example of Animal-like
Protists that move with cilia
Paramecium
III. Animal-like Protists
3. Pseudopod “false feet”– temporary
projections of cytoplasm for amoeboid
movement
Animal-like Protists that move with
pseudopods (false feet)
Entamoeba – causes
amoebic dysentery or the
“revenge” (a bad case of
diarrhea)
Amoeba
III. Animal-like Protists
4. Nonmotile - “no movement”, do not move
Example – Plasmodium
Causes Malaria
IV. Plant-like Protists
Contain chloroplasts and perform
photosynthesis
Plant-like Protista produce OXYGEN, making
them one of the most important groups of
organisms.
Can be Unicellular or Multicellular
Examples of Unicellular
Plant-like Protists
Euglena Golden Algae
Diatoms
cell walls of Silicon
used as an abrasive
in toothpaste
Examples of Unicellular
Plant-like ProtistsKarenia & Gonyaulax
Cause “Red Tide”,produce nerve toxin that kills fish/humans (eutrophication)
Eutrophication
• Caused by the addition
of excess nutrients to a
body of water
• Can lead to depleted
oxygen levels & “dead
zones”
• Remember the saying:
“Too much of a good
thing can be bad!”
Examples of Multicellular
Plant-like Protists
Red Algae Brown Algae
Examples of Multicellular
Plant-like Protists
Sargassum Kelp
Examples of Multicellular
Plant-like Protists
Green Algae species
Volvox Spirogyra
V. Fungus-like Protists
Heterotrophs that absorb nutrients from dead or
decaying organic matter (decomposer)
Unlike true fungus, they do not have cell walls made
of chitin
Ex: Slime molds
IV. Fungus-like Protist examples
Water molds - white fuzz growing on fish
in aquariums
Kingdom Fungi
UNIT 10
Classification of Living OrganismsDomain Bacteria Archaea Eukarya
Kingdom Eubacteria Archaebacteria Protista Fungi Plantae Animalia
Cell type Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
Cell
Structure
Cell walls with
peptidoglycan
Cell walls without
peptidoglycan
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Cell walls
of cellulose; chloroplasts
No cell walls
or
chloroplasts
# of
cells
Unicellular Unicellular Most
unicellular;
some
colonial;
some
multicellular
Most
multicellular
some
unicellular
Multicellular Multicellular
Mode
of Nutrition
Autotroph or
heterotroph
Autotroph or
heterotroph
Autotroph or
heterotroph
Heterotroph Autotroph Heterotroph
Ex.Streptococcus,
Escherichia coli
(E. coli)
Methanogens, halophiles Amoeba,
Paramecium,
slime molds,
giant kelp
Mushrooms,
yeasts
Mosses,
ferns,
flowering
plants
Sponges,
worms, insects,
fishes, mammals
Kingdom Fungi Characteristics
• Eukaryotes- NUCLEUS
• Heterotrophs- cannot make own energy
(NO photosynthesis)
• Decomposers or Parasites
• BOTH unicellular (ex. yeast) AND
multicellular (ex. mushroom)
• Cell walls made of chitin
Application
What KINGDOM would an organism belong
to if it had the following characteristics?
• Eukaryotic
• Heterotrophic
• Multicellular
• Cell wall made of chitin
Role of fungi in environment• Decomposers
– convert organic waste into compounds
usable by plants (break down dead
organisms)
All organisms that die will become organic waste!
Fungi Structures• Hyphae
– thin filaments that make up the fungus body
Fungi Structures• Mycelium
– Big mass or group of hyphae below ground
Fungi Structures• Mushroom
– Fruiting body or reproductive structure,
usually above ground
Fairy Ring
Fungi Reproduction
• Asexual Reproduction
– No exchange of genetic material
– Fruiting body/reproductive structure
produces spores that are dispersed by wind,
water & animals
• Sexual Reproduction
– Exchange of genetic material
– Increases a population’s variation
– Increases chances of surviving & evolving
SEXUAL REPRODUCTION
ASEXUAL REPRODUCTION
Classification of Fungi
• Common Molds
• Sac Fungi
• Club Fungi
• Imperfect Fungi
Common Molds
• Rhizopus (common bread mold)
–Rhizoids – root-like hyphae that
penetrate the bread’s surface &
anchor it to the bread
–Stolons – stem-like hyphae that run
along the surface of bread
Sac Fungi
• Reproductive structure resembles a cup
• Yeast
–only unicellular fungi
–Reproduce asexually by budding
–Thrush: yeast infection of the mouth due to overuse of antibiotics
THRUSH
Club Fungi
• Reproductive structure
resembles a club
• Ex. Pigskin poison puffball, stinkhorn,
shelf fungus, bird’s nest fungi, common
mushroom, fly agaric (poisonous)
CLUB MUSHROOMS
BRACKET FUNGI
GILLS
Imperfect Fungi
• Do not have an observable sexual phase in life cycle
• Penicillium notatum (antibiotic penicillin)
• Parasites – Athlete’s foot & ringworm
ATHLETE’S FOOT
RINGWORM
MOLDY
ORANGE
Penicillium
Penicillium
Symbiotic RelationshipLichens
• A relationship between fungusand a photosynthetic organism
• Fungus collects water & minerals and protects autotrophs
• Algae or cyanobacteria provides food (performs photosynthesis)
• What type of eukaryotic organism is algae? – plant-like protist
• What type of symbiotic relationship is this?– Mutualism
• Often a pioneer organism
Lichens
Lichen Anatomy
Symbiotic RelationshipMycorrhizae
• A relationship between plant roots and fungi mycelia
• Roots provide products of photosynthesis, which are…? – Glucose and oxygen
• Fungi help plant absorbmore water, minerals & other nutrients
• Which type of symbiotic relationship?
– Mutualism
MYCORRHIZAE
Benefits of
Mycorrhizae
Plant with
mycorrhizae
on the right
Plant without
mycorrhizae
on the left
Other fun fungus facts
FUNGUS EATING ROUND WORM
Parasitic fungi
Cordyceps video