protein synthesis-how do we go from genotype to phenotype

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