Biology 300 Translation

mRNA Sequence

decoded into sets of three nucleotides

Nucleotide Sequence

translated into an amino acid sequence, groups of triplet nucleotide(codon) encodes a single amino acid

Several different what can encode the same amnio?

Codons

How many codons in total?

64

How many amino acids?

20

What do tRNA molecules do with codon sequences?

Recognize and bind to a codon sequence on 1 site and bind amino acids to another

What is a clover leaf structure?

Complex, double helical structure

What unpaired regions are critical for functional tRNA?

2 regions of unpaired nucleotides at either end of the tRNA

What is an anticodon?

an end that forms on a tRNA, has a set of 3 nucleotides that bind through base pairing to a complementary codon

Specific Enzymes

Different enzyme for each amino acid type

Small ribosomes

catalyzes the reaction of the tRNA with codon mRNA

Ribosomes (RBS)

• contains binding site for mRNA

• contains binding site for tRNA

A site

charged tRNA- binds to codon on mRNA

P site

aa attached to tRNA is linked to growing polypeptide chain

L site

used tRNA is then moved here for ejection after use

Start codon bases

AUG in RNA and tRNA

Initiator tRNA

contains methionine (starts)

Stop codon bases

UAA,UAG,UGA- these codons are not recognized by a tRNA

Release factors

binds to stop codon, alters activity of peptidyl transferase, catalyzes the addition of water instead of an aa

Proteins are made on polyribosomes

chain of ribosomes that mediate mRNA, included in start and stop codons

Ribosome is a Ribozyme

RNA molecule contains catalytic activity