Download DNA

Protein Synthesis-How do we go
from genotype to phenotype
Nucleic Acids Differences
RNA
DNA
• Single strand
• Has Us
• Can leave the
nucleus
• Ribose sugar
• 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.
• ATCAT TCGGGAT
UAGUAAGCCCUA
• CCATTACGGGA
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.wisconline.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.lewport.com/10712041113402793/lib/10712041113402
793/Animations/Protein%20Synthesis%20%20long.
swf
Write the anticodons for the
codons
• AUGCAUUAGGCCAU
UACGUAAUCCGGUA
• CGAAUACAGGAU
GCUUAUGUCCUA
Write the amino acid sequence
from the mRNA sequence.
• AUGCAGCAUUAUACC
Methionine glutamine histidine tyrosine threonine
• CGAAUACAGGAU
Arginine isoleucine glutamine aspartic acid