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This article provides an overview of viruses and bacteria, including their structures, characteristics, and methods of reproduction. It discusses topics such as viral vaccines, retroviruses, different types of bacteria, and their energy sources. The article also covers bacterial respiration and reproduction methods such as binary fission, conjugation, and spore formation.
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Viruses & Bacteria www.assignmentpoint.com
What are Viruses A virus is a non-cellular particle made up of genetic material and protein that can invade living cells. www.assignmentpoint.com
T4 Bacteriophage www.assignmentpoint.com
Herpes Virus www.assignmentpoint.com
Escherichia Coli Bacterium E. coli is a bacterium. That is a crude cell, it is not a virus because viruses are protein containers with DNA cores or RNA cores. www.assignmentpoint.com
E. Coli and the Bacteriophage What it looks like in real life www.assignmentpoint.com
The Structure Of a Virus • Viruses are composed of a core of nucleic acid • The Nucleic acid core is surrounded by a protein coat called a capsid • The Nucleic core is either made up of DNA or RNA but never both www.assignmentpoint.com
Cycle of Lytic and Lysogenic www.assignmentpoint.com
Vaccines • Viruses grown on chicken embryos are attenuated vaccines • Another type of vaccine is made by heat killing the virus www.assignmentpoint.com
Retrovirus • Change DNA into RNA. • Example of a Retrovirus is HIV www.assignmentpoint.com
A typical, "minimal" retrovirus consists of: • an outer envelope which was derived from the plasma membrane of its host • many copies of an envelope protein embedded in the lipid bilayer of its envelope • a capsid; a protein shell containing • two molecules of RNA and • molecules of the enzyme reverse transcriptase www.assignmentpoint.com
Bacteria Cell www.assignmentpoint.com
Prokaryotes • Cells that do not have a nucleus • Exist almost every where on earth • Grow in numbers so great you can see them with the unaided eye • Are placed in either the Eubacteria or the Archebacteria Kingdoms • Make up the smaller of the two kingdoms www.assignmentpoint.com
Eubacteria • Make up the larger of the two prokaryote kingdoms • Generally are surrounded by a cell wall composed of complex carbohydrates www.assignmentpoint.com
Cyanobacteria • Photosynthetic bacterium • Bluish-greenish color • Contain membranes that carry out the process of photosynthesis • Do not contain the same type of chloroplasts as plants do • This bluish-greenish algae can be found nearly everywhere on earth. • Can survive in extremely hot environments and even extremely cold environment www.assignmentpoint.com
Archaebacteria • Lack important carbohydrate found in cell walls • Have different lipids in their cell membrane • Different types of ribosomes • Very different gene sequences • Archaebacteria can live in extremely harsh environments • They do not require oxygen and can live in extremely salty environments as well as extremely hot environments. www.assignmentpoint.com
Identifying Prokaryotes • Cell Shape • Cell Wall • Movement www.assignmentpoint.com
Bacterium Shapes • Cocci~ Sphere shaped bacteria • Bacillus~ Rod shaped bacteria • Spirrillium ~ Spiral shaped bacteria • Flagella~ Leg-like structures that help to propel the bacterium. www.assignmentpoint.com
Gram + and Gram – Bacterium Cell Walls www.assignmentpoint.com
Cellular Walls • Chemical nature of a cell wall can be determined by Gram Staining • By finding out what color the cell produces when it is gram stained you can figure out the type of carbohydrates in the cell wall www.assignmentpoint.com
Movement • Flagella ~ Tail like structure the whips around to propel the bacterium • Cillia ~ Miniature flagella surround the cell that help to “swim” • Non motile ~ Sticky cillia like structures that keep the bacterium from moving www.assignmentpoint.com
Flagella www.assignmentpoint.com
Bacteria and their energy • Autotrophs • Chemotrophs • Heterotrophs www.assignmentpoint.com
Autotrophs • Make their own energy • Using Solar energy • Eg. Cyanobacteria www.assignmentpoint.com
Chemotrophs • Make own Energy • Using Chemical energy • Eg. Archaebacteria www.assignmentpoint.com
Heterotrophs • Obtain food • By eating • Eg. E-coli www.assignmentpoint.com
Obligate Anaerobes Facultative Anaerobes Obligate Aerobes Live without Oxygen Can live with or without oxygen Cannot live without oxygen. Bacteria Respiration www.assignmentpoint.com
Bacteria Reproduction • Binary Fission • Conjugation • Spore Formation www.assignmentpoint.com
Cellular organism copies it’s genetic information then splits into two identical daughter cells www.assignmentpoint.com
Conjugation • A type of Bacteria Sex • Two organism swap genetic information, that contains the information such as a resistance to penicillin www.assignmentpoint.com
Spore Formation: Endospore • A type of dormant cell • Exhibit no signs of life • Highly resistant to environmental stresses such as: -High temperatures -Irradiation -Strong acids -Disinfectants • Endospores are formed by vegetative cells in response to environmental signals that indicate a limiting factor for vegetative growth, such as exhaustion of an essential nutrient. www.assignmentpoint.com
Symbiosis • Close relationship between to species in which at least one species benefits from the other • Live together for LIFE www.assignmentpoint.com
Parasitism • Bacteria exploit the host cell, injuring them • Eg. Mychobacterium tuberculosis www.assignmentpoint.com
Mutualism • Symbiosis in which two of the species live together in such a way that both benefit from the relationship • Eg. E-coli www.assignmentpoint.com
Nitrogen Fixations • Process by which nitrogen in the atmosphere is converted into a form that can be used by living things www.assignmentpoint.com
THE END www.assignmentpoint.com
