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