TRANSLATIONUsing RNA to make Protein

WHAT DOES IT MEAN TO TRANSLATE?

Definition in English: to turn from one language into another; to change form

Definition in science: to read the coded message of an RNA molecule and synthesize a new poly-peptide molecule (aka protein) at the ribosome in the cytoplasm

Definition in our own words: use RNA to make protein

KINDS OF RNA

Before we talk about translation, you should know:

There are 3 types of RNA involved in the process of making protein mRNA: messenger RNA carries the message of

how to make a protein (this is the one we talked about yesterday!)

tRNA: transfer RNA transfers amino acids to the ribosome during translation

rRNA: ribosomal RNA is one small piece making up the ribosome

KINDS OF RNA

mRNA

KINDS OF RNA

tRNAAmino Acid

Folded RNA Strand

Anticodon (complementary to the mRNA codon)

KINDS OF RNA

rRNA

Ribosome

Ribosomal RNA

THE GENETIC CODE

The mRNA molecule carries the message of how to make the specific protein

That message is coded

Let’s learn how to crack that code!

THE GENETIC CODE On the mRNA molecule, bases are read 3 at a

time A group of 3 bases in a row is called a codon There are 64 possible different codons that

code for the 20 different amino acidscodon formethionine (Met)

codon forleucine (Leu)

THE GENETIC CODE

How do you know which codons code for which amino acids?

Use this!!!

THE GENETIC CODE

AUG is the start codon This is where translation will begin

UAA, UAG, UGA are stop codons This is where translation will end

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:UCG-CAC-GGU

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:UCG-CAC-GGU

How many codons are there?

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:UCG-CAC-GGU

How many codons are there?3

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:UCG-CAC-GGU

How many codons are there?3

What amino acids are coded for?

PRACTICE TRANSLATING CODONS:

Codon=3 nucleotides that are read together

If this is the strand of mRNA:UCGCACGGU

The codons are:UCG-CAC-GGU

How many codons are there?3

What amino acids are coded for?Serine, Histadine, Glycine

THE PROCESS

mRNA molecule leaves nucleus and binds with ribosome

Beginning at the start codon, ribosome binds tRNA molecules with mRNA molecules according to correct codon—anticodon pairing So for example, if the codon GAC is on the mRNA

molecule, a tRNA molecule with the anticodon CUG will bind to it

The tRNA molecule brings its amino acid, which the ribsosome will bind to other amino acids being brought in to make a polypeptide chain (protein)