Chapter 17.4: From Gene to Protein
Terms in this set (9)
Describe the structure of the tRNA molecule
tRNA is composed of 80 nuclotides. Complimentary sequences in this molecule hydrogen bond with each other causing the molecule to fold upon itself into the general shape of an "L" with a loop that has the anticodon and an exposed 3" end that is the attachment site for an amino acid.
What class of related enzymes adds amino acids to tRNA molecules
How do he aminoacytl-tRNA synthetases add the correct amino acid to the correct tRNA molecule?
The active site of aminoacytl-tRNA synthetases only bind a specific combination of tRNA and amino acid. Bc of this there are 20 different aminoacytl-tRNA synthetases for each of the different 20 amino acids
Describe the process by which aminoacytl-tRNA synthetases addspecific amino acids to specific tRNA's
1) the active site of the aminoacytl-tRNA synthetase binds the amino acid and ATP
2)the ATP loses two groups and bonds the amino acid as AMP
3)Appropriate tRNA covalently bonds theamino acid as AMP
4)the tRNA charged with amino acid is released by the enzyme
Describe the concept anticodon wobble
This process allows anticodon to bond with more than one codon. This represents a loosening of the base paring rules.
What is he general function of ribosomes?
They help sepcific coupling of tRNA anticodons with mRNA during protein synthesis
Dscribethe components of a ribosome
There is a small and a big subunit, each made of proteins and one or rRNA
What are the differnces between eukaryotic ad prokaryotic ribosomes medically important?
Bc some drugs prevent the actions of prokaryotic ribosomes, while leaving eukaryotic ribosomes unaffected
Describe each of the binding sides of ribosomes
P site: holds the tRNA carryig the growing polypeptide chain
A site: holds the tRNA carrying the next amino acid to be added to the polypeptide chain
E site: where tRNA exits the ribosome, after giving the amino acid to the polypeptide chain