protein synthesis-how do we go from genotype to phenotype
TRANSCRIPT
Protein Synthesis-How do we go from genotype to phenotype
Nucleic Acids Differences
RNA• Single strand
• Has Us
• Can leave the nucleus
• Ribose sugar
DNA• Double stranded
helix
• Has Ts
• Stays only in the nucleus
• Deoxyribose sugar
3 types of RNA– Messenger RNA
(mRNA)-is made by copying the DNA• Takes strand message
to ribosome– Transfer RNA (tRNA)-
carries the correct amino acid to the ribosome from the cytoplasm
– Ribosomal RNA (rRNA)-makes up the ribosome
Transcription• Where: Nucleus
• What: takes the DNA message and makes mRNA
• Why: DNA can’t leave the nucleus but the message must get to the ribosome
• You are now using U’s no T’s.
• RNA polymerase – Enzyme that brings in RNA nucleotides to match up with
DNA
TRANSCRIBE THESE ON YOUR NOTEGUIDE.
• A T C A T T C G G G A T
• C C A T T A C G G G A
UAGUAAGCCCUA
GGUAAUGCCCU
SPLICING
Before the mRNA can go to the ribosome, it needs to be spliced.– The junk (parts of the DNA that are noncoding
regions) called introns need to be cut out.– Exons (coding regions) are then stuck together.
This is the correct concise message.
Translation• Where: ribosome
• What: tRNA brings in amino acids to the ribosome– tRNA anticodon: 3 bases that are complementary to
mRNA
• All mRNA start with the
codon AUG
• Protein Synthesis stops
when a stop codon is
reached.
What determines what amino acid is attached to the tRNA?
• Is it mRNA or tRNA?
mRNA
Watch the animation.http://www.wisc-
online.com/objects/index.asp?objID=AP1302
Does it matter what order the amino acids are in?
• The order of amino acids dictates the shape of the protein.
• The shape determines the function of the protein.
• Wrong order, wrong shape, no function
• http://www.lew-port.com/10712041113402793/lib/10712041113402793/Animations/Protein%20Synthesis%20%20long.swf
Write the anticodons for the codons
• A U G C A U U A G G C C A U
• C G A A U A C A G G A U
UACGUAAUCCGGUA
GCUUAUGUCCUA
Write the amino acid sequence from the mRNA sequence.
• A U G C A G C A U U A U A C C
• C G A A U A C A G G A U
Methionine glutamine histidine tyrosine threonine
Arginine isoleucine glutamine aspartic acid