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Lecture 2

Lecture 2 - Biodiversity.docx

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BIOL 1000
Michael Gadsden

Biology 1010 Lecture 2 Biodiversity  Calanolide A: o Derived from the Bintangor tree o Non-nucleoside reverse transcriptase inhibitor (NNRTI) o In clinical trials to fight HIV  Tested for anti-tumour activity (anti-cancer)  No effect vs. Cancer cells but success vs. HIV (virus that attacks the human immune system [T-cells])  Many anti-viral and anti-cancer drugs involve the inhibition of nucleotide synthesis (blocks DNA from replicating) o This is usually done by blocking the action of specific enzymes  Viruses enter host cells (DAN/RNA or whole virus) and uses the host cell’s “machinery” (enzymes) to replicate new viruses o The virus bursts the host cell and re-infests other cells o The virus will bind to a specific host cell membrane protein (this is the initiation of the infection) o Therefore there is a specific host to virus range o CENTRAL DOGMA: model that “all cells go through this pattern”  DNA  RNA  Polypeptide  With REVERSE TRANSCRIPTASE: DNA  RNA  DNA o Many viruses have an RNA genome (RNA genome carries all of the RNA plus reverse transcriptase)  When it is all injected, copy DNA (cDNA) is produced in the host’s cytoplasm  These viruses are called retroviruses because they go backwards and create DNA from RNA  But virus uses mainly host enzymes so they are difficult to kill  RNA transcriptase is usually what the scientists want to destroy  Most Reverse Transcriptase inhibitors are nucleoside derivatives (analogs)  Bind to an enzyme involved in the synthesis of the cDNA and that includes nucleotide synthesis and blocks it’s action  Nucleoside analogs can affect post-cell enzymes  side effects  NNRTI’s should have less effect on us and just a bunch of effects on the virus itself  We can get affected because our enzymes are very similar due to the fact that they are eukaryotes  Biodiversity is good because of things like viagara  Antigenic Shift o Two or more viruses combine in a single cell and hybridize to a new (relatively undetectable) virus (antigen) o Flu viruses can affect multiple hosts o More than one flu virus can infect a single cell  I.E. the human flu virus and the avian flu virus into a pig  The proteins (etc.) mix together to create a hybrid virus (TOTALLY NEW) o Normally, new organisms develop by evolution and this is slow  Mutations  selection  Yes/No  best organism o “SUPERBUGS” follow the same idea  H1N1, H5N2: o refers to coat membrane with phospholipids and proteins o On the inside, genome and RNA o H is Hemagglutenin (a protein) o N is neuraminidase o Number refers to the different strains o Antigens – because antibodies bind to foreign organic molecules like proteins  Recognise and destroy  Antigens are the protein recognized by the antibodies  Levels of Communities o Cell, Multi-cellular Organism, Population, Community, Ecosystem, Biosphere o Cell – smallest unit with the capacity to live and reproduce interdeopendantly or as part of a multicellular organism o Multi-cellular Organism – individual consisting of interdependent cells o Population – Group of individuals of the same species that occupy an area o Community – Populations of all species that occupy the same area o Ecosystem – Group of communities interacting with their shared physical environment (essentially the edge of the water affecting the beach) o Biosphere – All regions of the earth’s crust, waters and atmosphere that sustain life  Diversity of Life o Note: Protozoa – single cellular eukaryotes  Light and Life o Prototroph – can synthesize their own amino acids o Auxotrophs – Must absorb some or all of their own amino acids  What is a species? o Often  organisms that can breed to produce fertile offspring (as a population) o Bacteria  they don’t mate (they divide on their own and by binary fission)  Similar biochemistry (characteristics, DNA)  Based on historical grouping they may have to change names of species in
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