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