P ROKARYOTES AND V IRUSES Eubacteria – Structure, Metabolism and Reproduction Archaea – Structure, Metabolism and Reproduction Viruses – Structure, Metabolism.
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PROKARYOTES AND VIRUSESEubacteria – Structure, Metabolism and Reproduction
Archaea – Structure, Metabolism and Reproduction
Viruses – Structure, Metabolism and Reproduction
EUBACTERIA – STRUCTURE made of prokaryotic cells that include the following structures:
capsule sticky outer coating that prevents water loss, resists high temperatures and
controls entry to cells only found in some bacteria
cell wall made of peptidoglycan
cell membrane DNA
large chromosome plasmid – small loop of DNA
ribosomes pilli
cytoskeleton projections on the outside of cell allow for conjugation
flagellum cytoskeleton projections on the outside of cell allow for movement
EUBACTERIA - STRUCTURES
shapes, size and arrangement are variable three common shapes include:
coccus bateria round shape
bacillus bacteria rod shape
spirillum bacteria spiral shape
three common arrangements include: diplo arrangement
bacteria that exist in pairs staphylo arrangement
bacteria that exist in clumps strepto arrangement
bacteria that exists in strings
EUBACTERIA – METABOLISM metabolism varies between eubacteria can be classified by how they obtain nutrients
autotrophic bacteria create their own food using inorganic substances
heterotophic bacteria consume other organisms containing organic substances
can be classified by their need for oxygen obligate aerobe bacteria
require oxygen to break down food for energy facultative aerobe bacteria
can use oxygen to break down food for energy (aerobic respiration and fermentation)
can break down food without oxygen (anaerobic respiration and fermentation)
obligate anaerobes cannot live in the presence of oxygen
EUBACTERIA – REPRODUCTION
reproduce asexually using binary fission1. cell grows2. chromosomes
duplicate3. cell grows4. cell divides into two
cells5. daughter cells have
the same genetic makeup as the parent cell
EUBACTERIA – REPRODUCTION
are able to exchange DNA or acquire new DNA from their environment to increase genetic diversity
conjugationtwo eubacteria attach
using their pillia copy of a plasmid
passes from one eubacteria to another
http://www.youtube.com/watch?v=O-EdX4MaMFE&feature=related
EUBACTERIA – REPRODUCTION transformation
eubacteria pick up discarded DNA from their surroundings and incorporate this DNA into their chromosome
if DNA comes from a different species this process is known
as horizontal gene transfer
http://www.youtube.com/watch?v=MRBdbKFisgI&feature=related
EUBACTERIA – EXAMPLES
Type Characteristics Picture
proteo-bacteria
• most are photosynthetic• thought to be ancestors of mitochondria• cause many diseases
• bubonic plague, gonorrhea, ulcers
green bacteria
• photosynthetic• found in salt-water and hot springs
cyano-bacteria
• photosynthetic• thought to be ancestors of chloroplasts• found in aquatic ecosystems as producers and decomposers
EUBACTERIA – EXAMPLES
Type Characteristics Picture
gram-positive bacteria
• cause many diseases• strep throat, meningitis
• used in food production• yogurt
spirochetes • spiral shaped flagellum to move in a corkscrew pattern• cause syphilis
chlamdias • parasites• cause chlamydia
ARCHAEA – STRUCTURE AND REPRODUCTION
Structuremade up of prokaryotic cells that include the following structures:
cell wall with no peptidoglycan
cell membrane DNA
Reproductionreproduce asexuallymechanism is unknownmost likely similar to binary fission
ARCHAEA – METABOLISM metabolism varies between archaea
methanogens live in low-oxygen environments (swamps, marshes, digestive
tracts of mammals and insects) use methane to generate energy
halophiles live in high salt environments (Dead Sea, foods preserved by
salting) use light and other organisms to generate energy
extreme thermophiles live in hot environments (hot springs and hydrothermal vents) use heat energy to generate energy
psychrophiles live in cold environments (Antarctic and Arctic oceans) mechanism to generate energy is unknown
VIRUSES – STRUCTURE
not made of cells non-living structures that
include the following components: DNA or RNA
viruses that contain DNA are called DNA viruses hepatitis B
viruses that contain RNA are called RNA viruses HIV/AIDS
capsid protein coat that surrounds the
genetic material of the virus
VIRUSES - STRUCTURE
more complex viruses can also include: envelop
created on the outside of a viruses when it leaves the host cell
part of the host cell’s membrane
sheath, plug and tail fibers found only in
bacteriophages (phages) viruses that infect bacteria structure used to inject
genetic material into the host
VIRUSES – METABOLISM
only active when they have infected a living cell
do not perform any life functions on their own
have no metabolic structures or systems
VIRUSES – REPRODUCTION
only active when they have infected a living cell
1. Virus infects host cell and inserts DNA/RNA into the host.
2. Viral DNA/RNA forms a loop.
3. DNA/RNA can be copied by inserting itself into the hosts chromosomes (lysogneic cycle).
4. DNA/RNA instructs cells to make new viral DNA/RNA and capsids (lytic cycle).
5. Newly formed viruses are released when the host cell burts (lytic cycle).
http://www.youtube.com/watch?v=Rpj0emEGShQ
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