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Everything in your body is Everything in your body is a protein, or is MADE by a a protein, or is MADE by a

protein!protein!

InsulinActin & Myosin

Melanin

Elastin

Keratin

Hemoglobin

Heparin

4 letters in RNA’s genetic “alphabet” A C U G

20 letters in protein’s polypeptide “alphabet”

How to get between the two? Translation!

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Begin in the middle and work your way out

ExampleExample:

U A C

Tyrosine!Tyrosine!

p303 in your book 5

CAG Glutamine

AAA Lysine

GGA Glycine

GGU Glycine

UUC Phenylalanine

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AUG Methionine OR “start”

UAAUAG UGA “Stop” codons Act like the period at the end of a

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We know HOW to put it together, but what will actually assemble that protein?

The ribosomeribosome is our protein assembly factory!

ribosomeribosome

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Ribosome.avi

During translation, the cell uses information from mRNA to produce proteinsproteins

“Knowing” which codon goes to each amino acid is the job of tRNAtRNA

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Each tRNA molecule has the following: Amino acid Amino acid attached to

one end Region of three unpaired

bases at other end▪ (What would you call the opposite

of a codon?)▪ Anticodon!

▪ Anticodon bases are complementary to one of the mRNA codons

AnticodonAnticodon11

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On the ribosome, the tRNA begins binding to its appropriate site on the mRNA

ribosome

amino acid

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The next tRNA molecule binds to the next codon on the mRNA

The ribosome now links those two amino acids with a peptide bond

The ribosome also breaks the first tRNA-aa bond

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ribosomeribosome

mRNAmRNA

tRNAtRNA

proteinprotein

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The polypeptide (protein) chain continues to grow until a stop codon is reached (UAG, UGA, UAA)

When it reaches a stop, the polypeptide chain is released into the wild

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I wonder how much $$ the government spent so I can eat bamboo

for 14 hours…

ribosomeribosome

mRNAmRNA

tRNAtRNA

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