Presentation on theme: "From DNA to protein And viruses And bacteria"— Presentation transcript:
1From DNA to protein And viruses And bacteria Protein SynthesisFrom DNA to proteinAnd virusesAnd bacteria
2Central Dogma FROM GENOTYPE TO PHENOTYPE (From DNA to proteins) You Tube Protein Synthesis (2:51)DNA Transcription and Protein Assembly (3:02) From DNA to proteinsFROM GENOTYPE TOPHENOTYPE (From DNA to proteins)
8The 3 RNA’smRNA – messenger RNA – codes from DNA in the nucleus to take the genetic code to the ribosome in the cytoplasmtRNA – transfer RNA – brings a specific amino acid to the ribosomerRNA –ribosomal RNA – plus protein makes up a ribosome
9Transcription: DNA to mRNA DNA never leaves the nucleusIt codes to mRNA to take themessage outside the nucleusTRANSCRIPTION YOUTUBE (1:53)
10RNA polymerase (RNAP) The enzymes that makes RNA from the DNA template
11Not all RNA nucleotides make the cut: Introns and Exons Primary mRNA = exons + intronsINTRONS = discarded, noncoding region of mRNAEXONS = the coding regions, spliced together RNA are called also = Mature mRNARNA SplicingYoutube (1:38)
13SPLICING ANIMATION snRNP’s Spliceosome Seriously detailed splicing youtube (1:39)McGraw-Hill How Splicesosomes Process RNABefore the mRNA leaves the nucleus, the introns are removed, and the exons are spliced together.
16Transcription Promotors DNA sequences at start site (recognize TATA BOX)RNA polymerase and accessory proteins (transcription factors) bind to the promoter to initiate production of an mRNA transcription.TATA
17Transcription Terminator mRNA is cut free from DNA
18The mRNA travels out of the nucleus through nuclear pores to a ribosome in the cytoplasm The mRNA binds to a ribosomeRibosome translates codons (use chart)
19TRANSLATION Translation Youtube (2:06) mRNA (genetic language) needs to be translated into protein language (chain of amino acids)Translation Youtube (2:06)
20TRANSLATION Coding from mRNA to making protein (at the ribosome) DNA Translation Youtube (2:06)
21tRNA transports amino acids to ribosomes There is a specific amino acid for each tRNA
22Job of tRNAComplements the codon of mRNA and picks up the appropriate amino acidANIMATION:Animation of Translation
23Note the A P E sites Central Dogma youtube (3:03) A site – Amino acid is dropped offP site – Polypeptide buildsE site – tRNA exits (after giving its amino acid to building polypeptide chain)APE sites of Ribosome youtube (1:31)
24A P E Sites at the Ribosome Translocation: movement of tRNA across the ribosome
25Notice AUG codon means “start” building a new protein Notice AUG codon means “start” building a new protein. UAA, UAG, UGA mean “stop’ building the protein.
26There are 20 Amino Acids These 20 are shared by all living organisms What does CAC code for?histidine
27Translation Initiation mRNA attaches to the ribosome (AUG –start codon)
28Translation Elongation tRNA brings amino acids to the ribosome
29Translation Termination mRNA reaches one of the STOP codonsBond breaks the last tRNA and its amino acid to release the polypeptide bond
30Cooooool Protein Synthesis 3-D CENTRAL DOGMA (2:52)
31All mRNA’s start with AUG, so all DNA genes start with______?
33THINK:What would happen if something caused the base sequence to change?What sorts of things could cause this?Could the base changes be repaired?Would those changes be passed on to the individual’s offspring?
34MUTATION:A change in the base sequence of a gene resulting in a different base sequence and thus different amino acid sequence.What causes mutations? MUTAGENSThalidomide baby…
35EX: X-rays UV light cigarette components Hazardous chemicals Mutagen =any source of mutation is a physical or chemical agentEX: X-raysUV lightcigarette componentsHazardous chemicals
37Mutation AnimationsBBC - Education Scotland - Higher Bitesize Revision - Biology - Genetics and adaptation - Mutations: Revision 2EXPLAIN HOW EACH MUTATION IS DIFFERENT FROM THE ORIGINAL DNA SEQUENCE
38Gene (point)mutations SUBSTITUTION – Replace one base for another. Minimal effectADDITION – Adding a baseDELETION – removing a baseAddition/deletions cause a complete Frame Shift that affects the whole gene.
39Mutation Lingo Mutation = any change in nucleotide sequence of DNA Reading frame = triplet groupingMutagenesis = creation of mutations
40More Mutation LingoNonsense mutation = change an amino acid into a STOP codonMissence mutation = change the amino acid codingSilent mutation = no change in protein product
41Chromosome Mutations Translocation Inversion Segment of a same chromosome is turned end to endhas moved one segment of achromosome to a differentchromosome
55Every virus has two stages a dormant, particulate, transmissible stage called the virion stagean active, intracellular stage called the infectious stage
56Infectious Stage: Lytic Infection 1.attachment2. Insertion of virus DNA3. replication of virus components4.packaging and assembly of new virions5. exit from cell –”lysis” bursts
57The Lytic Cycle Lytic Cycle Go to Section: Bacteriophage protein coat Bacteriophage DNABacterialchromosomeBacteriophage attaches to bacterium’s cell wallBacteriophage enzyme lyses thebacterium’s cell wall, releasingnew bacteriophage particles thatcan attack other cells.Lytic CycleBacteriophage injects DNA into bacteriumBacteriophage proteins and nucleic acids assemble into complete bacteriophage particlesBacteriophageBacteriophage DNABacteriophage proteinBacteriophage takes over bacterium’s metabolism, causing synthesis of new bacteriophage proteins and nucleic acidsGo to Section:
59Lysogenic InfectionThe viral DNA becomes integrated into the bacterial DNA after infection. It is replicated along with the host DNA when the host reproduces. The viral DNA is referred to as a prophage.
60A Lysogenic Infection Go to Section: Lytic Cycle Lysogenic Cycle BacterialchromosomeBacteriophage DNABacteriophage injects DNA into bacteriumBacteriophage DNA (prophage) can exit the bacterial chromosomeLytic CycleLysogenic CycleBacteriophage DNA forms a circleBacteriophage DNA (prophage) may replicate with bacterium for many generationsBacteriophage enzyme lyses the bacterium’s cell wall, releasing new bacteriophage particles that can attack other cellsProphageBacteriophage proteins and nucleic acids assemble into complete bacteriophage particlesBacteriophage DNA inserts itself into bacterial chromosomeGo to Section:
61DIAGRAM COMPARISONLytic and Lysogenic Infections
62Virus ExamplesRNA instead of DNA: cold, flu, HIV, polio, measles, mumpsDNA viruses: herpes. Chicken pox, hepatitisHerpes infections may flare up when under stress, a cold, or sunburn