PROTEIN SYNTHESIS NOTES #1

Review What is transcription?

Copying of DNA onto mRNA Where does transcription occur?

In the Nucleus When copying DNA onto mRNA there

is no Thymine (T) instead there is Uracil (U) A – U; G – C

More Review What is Translation?

The changing of mRNA into a protein

Where does Translation occur? In the Ribosome

What is a codon? 3 bases on mRNA

What is an anticodon? 3 bases on tRNA

Last of the Review What type of RNA carries the amino

acids to the ribosomes? tRNA

What is the start codon? AUG

What are the stop codons? UGA, UAA and UAG

Codon Wheel or Codon Chart Each codon (3 bases on mRNA) codes

for a particular amino acid You find which amino acid is coded for

by looking on one of the codon charts Codon Wheel – start from the middle

and work your way out Codon Chart – Start on the left side,

then the bottom (or top) and then the right side

The Genetic Code (mRNA)

A

LysineLysine

AsparagineAsparagine

ArginineArginineSerineSerine

IsoleucineMethionineIsoleucineIsoleucine

ThreonineThreonineThreonineThreonine

AGUC

G

Glutamic acidGlutamic acidAspartic acidAspartic acid

GlycineGlycineGlycineGlycine

ValineValineValineValine

AlanineAlanineAlanineAlanine

AGUC

U

“Stop” codon“Stop” codon

TyrosineTyrosine

‘Stop” codonTryptophan

CysteineCysteine

LeucineLeucine

PhenylalaninePhenylalanine

SerineSerineSerineSerine

AGUC

C

GlutamineGlutamineHistidineHistidine

ArginineArginineArginineArginine

LeucineLeucineLeucineLeucine

ProlineProlineProlineProline

AGUC

A G U C

1st Base in

Codon

3rd Base in Codon

2nd Base in Codon

Practice Using One of the Codon Charts

If the codon is GCC, what is the amino acid?Alanine

If the codon is UGG, what is the amino acid?Tryptophan

If the codon is AGU, what is the amino acid?Serine

More Practice Using One of the Codon Charts

Can you go backwards? How many codons are there for

the amino acid proline? 4

Name the 4 codons for proline. CCU, CCC, CCA, CCG

Name 2 of the codons for arginine. AGG, AGA, CGG, CGA, CGC, CGU

Protein Synthesis Practice

If one side of the DNA strand is:

TACACCGGTCCATTTACTWhat is the complementary

(other) side of the DNA strand?

ATGTGGCCAGGTAAATGA

Protein Synthesis Practice

Using the original DNA strand:

TACACCGGTCCATTTACTPerform transcription – what

is the mRNA produced? AUGUGGCCAGGUAAAUGA

Protein Synthesis Practice

Break the mRNA into codons (groups of 3):

AUGUGGCCAGGUAAAUGAPerform Translation- what is

the protein produced? Meth – Tryp – Pro – Gly – Lys (stop)(start)

Another Protein Synthesis Practice Problem

If DNA is: TACAATGCCAGTGGTTCGCACATTWhat is the mRNA?

AUGUUACGGUCACCAAGCGUGUAAWhat is the protein made?Meth-Leu-Arg-Ser-Pro-Ser-Val (stop)