BACTERIA. What are Monerans? Monerans are believed to have existed longer than any other life form on Earth Most monerans are types of BACTERIA.
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Kingdom MoneraBACTERIA
What are Monerans?Monerans are believed to have existed
longer than any other life form on EarthMost monerans are types of BACTERIA
What Do We Know About Bacteria?Unicellular organisms:
One celled organismsDo not have a true, membrane bound nucleus
Can be found almost everywhereSome bacterial are bad for youSome bacterial are good for youSome bacterial will not affect your health at
all
What Do Bacterial Look Like?Bacterial are usually one of three shapes: Rods Spheres
Spirals
How Do Bacterial Reproduce?Bacterial reproduce asexually
Reproduce by dividing in half
Binary FissionBacterial split into two cellsEach cell gets an exact copy of the DNA
Some bacteria can actually reproduce every 20 minutes
Anything Else about BacteriaSome contain Chlorophyll and make their own food,
we call themAutotrophs
Others can’t make their own food, we call themHeterotrpohs
Some can get their energy from chemicals such as:Ammonia and Sulfur
Others live in odd place like:Deep sea ventsAntarcticaHot Springs
What is Their Function?Help decompose dead thingsLive in animals’ digestive system to digest
foodThey may cause diseases and they are called
germsSome can be killed off with antibiotics which
stop their reproduction process.Others can be prevented by vaccination, a
way of killing bacteria to help the body protect itself against the live bacteria
Name Something Else that Causes Diseases and Sickness, besides Bacteria or “Germs.”VIRUS!
Properties of viruses• no membranes, cytoplasm, ribosomes, or other cellular components• they cannot move or grow• they can only reproduce inside a host cell• they consist of 2 major parts - a protein coat, and hereditary material (DNA or RNA)• they are extremely tiny, much smaller than a cell and only
Review of DNA• Shape of a double helix•Base pairs held together by hydrogen bonds (weak)•Repeating units of nucleotides
Adenine <-> ThymineGuanine <-> Cytosine
Parasitic Nature•Obligate intracellular parasites•Specific to their hosts (human, dog, some can cross species)•They can only attack specific cells , the common cold is a virus that specifically attacks cells of the respiratory track (hence the coughing and sneezing and sniffling). •HIV specifically attacks white blood cells
Bacteriophage - a virus that infects bacteria
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Viral Reproduction
Lytic cycle = reproduction occurs, cells burst
Lysogenic cycle = reproduction does not immediately occur (dormancy)
Virulent = viruses that undergo both cycles
Viruses multiply, or replicate using their own genetic material and the host cell's machinery to create more viruses. Viruses cannot reproduce outside of the host.
1. Attachment2. Penetration - the virus is
engulfed by the cell (Cell can enter Lysogenic or Lytic Cycle)
3. Biosynthesis - viral components are made(protein coat, capsid, DNA/RNA)
4. Maturation - assembly of viral components
5. Release - viruses leave host cell to infect new cells(often destroys host)
Retroviruses -- RNA viruses that have a DNA stageHuman Immunodeficiency Virus - causes
AIDSRetrovirus (RNA inside a protein coat)Reverse Transcriptase makes DNA from the
virus RNADNA inserts into host DNAProteins are assembled from the DNA codeViruses assembled from the proteinsViruses released from the cell
Emerging Viruses
Emerging Virusesillnesses not previously known: AIDS, West
Nile Virus, SARS, Ebola, Bird FluCould be mutations of known virusesCould be viruses exposed when new areas
were developedCould have jumped species
How Do Vaccines Work?1. Once you have gotten a virus, such as
chicken pox, your body develops the immunity to that virus.
2. Vaccines are made by growing a weakened or killed form of the virus (often grown in eggs)
3. This form of the virus is injected into a person's body, which causes an immune response, and immunity to the virus.
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