* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Prokaryote vs. Eukaryote
Survey
Document related concepts
Ebola virus disease wikipedia , lookup
Viral phylodynamics wikipedia , lookup
Social history of viruses wikipedia , lookup
Endogenous retrovirus wikipedia , lookup
Oncolytic virus wikipedia , lookup
Introduction to viruses wikipedia , lookup
Bacteriophage wikipedia , lookup
Virus quantification wikipedia , lookup
Plant virus wikipedia , lookup
Papillomaviridae wikipedia , lookup
History of virology wikipedia , lookup
Transcript
Prokaryote vs. Eukaryote • 1st division Prokaryotes • Found in bacteria and archaea kingdoms • Characteristics include 1-10μm(micrometer-one millionth of a meter) lack a true nucleus so keep DNA in nucleoids no membrane bound nucleus or organelles many are anaerobic so they do not require O2 Unicellular Have a cell wall(peptidoglycan) Eukaryotes • Found in protists, plants, fungi, and animal kingdoms • Characteristics include 100-1000 μm Presence of a nucleus Presence of membrane bound organelles Ex: mitochondria is an organelle that gives energy most are aerobic so they require O2 for cellular respiration most are multicellular Summary chart • Prokaryotes – 1-10 μm – Lack a true nucleus – No membrane bound organelles or nucleus – Many are anaerobic – Unicellular – Have a cell wall • Eukaryotes – 100-1000 μm – Presence of a nucleus – Has membrane bound organelles – Most are aerobic – Mostly multicellular (pluricellular) Viruses • Debate over whether viruses are “alive” Arguments that they are not-living • Cannot live independently (require a host or remain dormant) (parasites of living cells!!) • Not Cellular Arguments that they are living • Contain genetic material (RNA and DNA) • Reproduce Classifying viruses 1) Classification based on capsid • protein coat that surrounds the genetic material of a virus Spherical Cylindrical Crystalline 2) Classification based on diseases they cause • Viruses that affect humans are divided into 21 groups based on the differences in their genome and replication methods How viruses replicate (no cellular division) 1) The Lytic Cycle • kills host cell • 5-step process: – Virus binds itself to host cell (attachment) – Injects the viral genetic material into the host cell (entry) – The host replicates the viral genetic material (replication) – New viral particles are assembled (assembly) – The host cell breaks (lysis) and releases new viral particles (release) which can go infect other cells. The Lytic Cycle • • • • • 1. Attachment 2. Entry 3. Replication 4. Assembly 5.a) Lysis b) Release How viruses replicate (cont’d) 2) The Lysogenic Cycle • Viral RNA becomes part of the cells chromosomes. It does not take over the cell but the RNA gets copied with the cell. The onset of disease can be postponed until the virus goes into its lytic cycle b)Process – Attachment – Entry – Viral DNA becomes part of the host cell’s chromosomes (provirus formation) The Lysogenic Cycle 1. 2. 3. Attachment Entry Provirus Formation Viral disease • Cyclical symptoms can be explained by the replication method of a virus ex. cold sores • appear during the lytic cycle • disappear during the lysogenic replication cycle (Virus is always in a person, never goes away so always susceptible to cold sores) Virus working for us Virus use in biotechnology: 1) Gene therapy i) addition of a specific gene into the virus ii) virus can deliver and force organism to replicate that gene iii) “typos” corrected ex. Parkinsons 2) Bacteriophages viruses attack bacteria (45 min = 200 new viruses) 3) Reovirus (Respiratory Enteric Orphan Virus) kills cancer cells -head, neck, lung, liver cancers - few side effects Prions • Protein 1) Do not contain RNA or DNA (not a virus) • Becomes harmful when it changes its molecular shape -because they can cause several deadly brain diseases such as: Creutzfeld-Jakob disease Mad-cow disease in bovine