BIOL 1050 Lecture 11 Outline of Last LectureI. TranslationII. Genetic CodeIII. MutationOutline of Current LectureI. Genetic ExpressionII. Virusesa. Viral replicationb. Emerging virusesc. Retrovirusesd. HIV/AIDSCurrent LectureI. Genetic Expressiona. How do cells become different from each other if they all (except our gametes) have the same DNA?b. Gene: the smallest unit of an inheritable trait.i. 1 gene= 1 RNA transcript (protein)c. Certain genes in a cell are turned “on” while others are turned “off”i. Genes that are “on” undergo transcription and translationii. Genes that are turned “off” do not functioniii. This determines the type of cell iv. Proteins turn them off/onv. Transcription factors regulate transcriptionvi. Each cell type has a different pattern of active genesII. Virusesa. Viruses are not quite alive or non-alivei. Have genesii. But are not cellular and cannot reproduce on their owniii. Most viruses are made of DNA or RNA (or both) wrapped in protein coativ. Must infect living cell with genetic material so that cell will make more virusesv. The virus takes a little bit of the cells membrane when it leavesvi. Viral replicationThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. After the virus binds to the host cells membrane the viral DNA is taken into the cell2. Viral DNA is replicated into dozens of new copies, using the hosts metabolic machinery and energy3. Viral mRNA is transcribed from the viral DNA4. New viral proteins are synthesized, again using the hosts protein production molecules5. The new viral DNA and proteins assemble, forming many new virus particlesvii. Antibiotic drugs work against bacterial infections but do not work against virusesviii. Emerging viruses1. New viruses and new forms of old viruses arise al the time2. Through mutations and evolution3. RNA viruses mutate more4. Small pox was the most devastating virus and killed 1/3 of anyone infected (millions)a. The first and only disease to be eradicated 5. Newly dangerous viruses includea. Ebolab. SARSc. New strains of the flu6. Some viruses are species specifica. Swine flui. Accidental host is the pigb. Avian fluc. The virus swaps genetic info and can then infect a differentspeciesix. Retroviruses1. Retroviruses do not have viral DNA2. Use viral RNA to make viral DNA in process of reverse transcription3. Then viral DNA can insert itself into host’s DNA to go through transcription and translation to make copies of virus4. RNA>DNA>inserts itself into hosts genome (is there for good)5. Does this on purpose x. HIV, the AIDS virus1. HIV: Human immunodeficiency virusa. Made of RNA and proteinsb. HIV is a virus that carries its genetic instructions in the form of RNA rather than DNA2. HIV replicationa. Reverse transcriptase (enzyme) uses viral RNA to make viral DNAb. Viral DNA enters hosts DNAc. Transcription make new RNA (viral and host)d. New virus particles are assembled and leave host cell3. HIV infects and kills cells used in immune systema. Immune system successfully fights for a whileb. Eventually immune system fails and AIDS developsi. Immune system no longer able to support itself <200 t cells per micro
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