Protein Synthesis
DNA-->RNA-->Protein-->Trait
One Gene one Protein
• Beadle and Tatum– Worked with the Mold Neurospora.• Looked at metabolic pathway to synthesize the amino
acid Arginine
• Studies of inherited metabolic disorders first suggested that phenotype is expressed through proteins
• Studies of the bread mold Neurospora crassa led to the one gene-one polypeptide hypothesis
http://wps.prenhall.com/wps/media/objects/1552/1589869/web_tut/21_04/21_04_01a.swf (has a narrator)
http://www.dnalc.org/view/16360-Animation-16-One-gene-makes-one-protein-.html (no narrator)
Figure 10.6B
Mutate wild type fungus
*Supply all mutant isolates with complete media
*Grow purified mutants with minimal media to find nutritional mutants
*Determine what is the nutritional limitation find mutation
There for the gene used to produce an enzyme that helps cells manufacture Arginine amino acid was mutated in that fungal strain
.
Beadle and Tatum This may not be totally accurate
Central DogmaOverview: http://www.wiley.com/legacy/college/boyer/0470003790/animations/central_dogma/central_dogma.swf
RNA vs DNA
• Differences between the two nucleotides– Sugar• Ribose instead of deoxyribose
– Nitrogenous bases• Uracil instead of Thymine
Types of RNA
• rRNA– Ribosomes are made or rRNA and Proteins
• tRNA– Folded into the “t” shape and carry an amino acid
on the end• M-RNA– Single Stranded
• HnRNA– SNRPs
rRNA and Proteins
tRNA
Central DogmaOverview: http://www.wiley.com/legacy/college/boyer/0470003790/animations/central_dogma/central_dogma.swf
Transcription vs Translation
• Transcription (DNA to RNA)– Copying mRNA from DNA– Promotor sequence– Some are modified before leaving nucleus (Eukaryotes)– Prokaryotes are not modified
• Translation (RNA to Amino Acid)– Initiation– Elongation– Termination
Transcription
• Sense vs Antisense.– Sense strant is the coding strand and would have the same
sequence as the mRNA with U’s replacing T’s.– The Antisense strand is the strand that is transcribed.
↓Template strand
RNA polymeraseReads DNA template 3’5’,
writes mRNA 5’ 3’
Transcription
• Promotor– Site that the RNA polymerase recognizes and binds to
begin the process of Transcription
• RNA Polymerase– Enzyme that reads 3’5’ and writes a 5’3’ mRNA
• Nucleoside Triphosphates– The nucleotides that are put in by the polymerases
• Terminator– Sequence that will code for a releasing factor
transcription detail: http://bcs.whfreeman.com/thelifewire/content/chp12/1202001.html http://www.dnalc.org/resources/3d/13-transcription-advanced.html Detailed realistic model http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf simple animation simple animation
Transcriptiontranscription detail: http://bcs.whfreeman.com/thelifewire/content/chp12/1202001.html http://www.dnalc.org/resources/3d/13-transcription-advanced.html Detailed realistic model http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf simple animation simple animation
Processing or not
Splicing (Eukaryotes)
http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter14/animation_quiz_3.html
http://www.four-h.purdue.edu/apple_genomics/flash/movie3.swf
http://bcs.whfreeman.com/thelifewire/content/chp14/1402001.html
Cap and Tail
Summary- eukaryotic control of gene expressionhttp://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter16/control_of_gene_expression_in_eukaryotes.html
mRNA Processing: The Movie from the “Virtual Cell Animation collection: molecular and Cellular biologyhttp://vcell.ndsu.edu/animations/mrnaprocessing/movie-flash.htm
Summary of Translation
Step by stephttp://www.stolaf.edu/people/giannini/flashanimat/molgenetics/translation.swf
Intro overviewhttps://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter3/animation__how_translation_works.html
Ribosome Sites
Ribosome Siteshttp://bcs.whfreeman.com/thelifewire/content/chp12/1202003.html
mRNA codes for AAhttp://bcs.whfreeman.com/thelifewire/content/chp12/1202002.html
• Degenerate Code
Translation
• T-RNA molecules are matched to the proper amino acid by an enzyme.
• Initiation, elongation, and translocation, and termination
• Location and Processhttp://www.dnalc.org/resources/3d/16-translation-advanced.html
Ribosome
Mutations and Protein Synthesis• Can produce new alleles
– Must be in the gametes to be passed on• Types of Mutations
– Point• Can be harmless because of redundency (Degenerate) of code
– Chromosomal• Duplication• Inversion• Translocation• Deletion
Point Mutation and Frame Shift
Point Mutation and Sickle Cellhttp://www.cleanvideosearch.com/media/action/yt/watch?videoId=1fN7rOwDyMQ http://www.cleanvideosearch.com/media/action/yt/watch?videoId=9UpwV1tdxcs
Outcome of Sicke Cell
Translocation
Inversion
Deletion
Duplication
Ribosome with tRNA and Amino Acids