Biology
Translation is the process by which a triplet base sequence of mRNA molecules are converted into a specific sequence of amino acids in a polypeptide chain in the cytoplasm of a cell. It consists of initiation, elongation, and termination.
The mRNA, a tRNA carrying the first amino acid of the polypeptide chain and the two subunits of a ribosome are brought together. After leaving the nucleus, the mRNA forms a reversible attachment to the mRNA binding site at the surface of a small ribosomal subunit. It recognizes a specific sequence on the mRNA just upstream of the initiation codon.
The initiation codon on the mRNA attracts its complementary tRNA, which carries the specific amino acid. This aminoacyl tRNA complex binds reversibly to the mRNA at the initiation site by hydrogen bonding via specific complementary base pairing with its anticodon.
It occupies the P site of a ribosome; translation starts as a translation initiation complex is formed. The initiation codon is most often AUG, which codes for the amino acid methionine.
Several ribosomes attracted to the mRNA simultaneously form a polyribosome. This is possible as once a ribosome has moved past the start codon, a second ribosome can attach to mRNA, thereby increasing efficiency of translation. The binding of the mRNA forms a translational complex and elongation of the polypeptide chain as translation proceeds. Newly formed polypeptide chains then enter the rough endoplasmic reticulum lumen and fold into its secondary/tertiary/quaternary structure in the cisternae. It is then packaged into vesicles and buds off and fuses with the soft endoplasmic reticulum and then the Golgi apparatus.
- Q: Compare And Contrast Transcription And Translation
Transcription occurs in the nucleus but translation occurs in the cytoplasm and rough endoplasmic reticulum. The two processes use different components and enzymes, transcription uses transcription factors and RNA polymerase whereas translation uses ribosomes...
- Amino Acid Activation
Codons of an mRNA molecule contain genetic messages that are carried by the mRNA and they need to be translated to form the corresponding sequence of amino acids that will form the polypeptide chain and subsequently the protein. The tRNA transfers amino...
- Initiation Involves Base Pairing Between Mrna And Rrna
KEY TERMS:The Shine-Dalgarno sequence is the polypurine sequence AGGAGG centered about 10 bp before the AUG initiation codon on bacterial mRNA. It is complementary to the sequence at the 3 end of 16S rRNA. KEY CONCEPTS: An initiation site on bacterial...
- Use Of Fmet-trnaf Is Controlled By If-2 And The Ribosome
KEY TERMS:The context of a codon in mRNA refers to the fact that neighboring sequences may change the efficiency with which a codon is recognized by its aminoacyl-tRNA or is used to terminate protein synthesis. KEY CONCEPTS: IF-2 binds the initiator...
- Protein Synthesis Occurs By Initiation, Elongation, And Termination
KEY TERMS:The A site of the ribosome is the site that an aminoacyl-tRNA enters to base pair with the codon. The P site of the ribosome is the site that is occupied by peptidyl-tRNA, the tRNA carrying the nascent polypeptide chain, still paired with the...
Biology
Translation
Translation is the process by which a triplet base sequence of mRNA molecules are converted into a specific sequence of amino acids in a polypeptide chain in the cytoplasm of a cell. It consists of initiation, elongation, and termination.
The mRNA, a tRNA carrying the first amino acid of the polypeptide chain and the two subunits of a ribosome are brought together. After leaving the nucleus, the mRNA forms a reversible attachment to the mRNA binding site at the surface of a small ribosomal subunit. It recognizes a specific sequence on the mRNA just upstream of the initiation codon.
The initiation codon on the mRNA attracts its complementary tRNA, which carries the specific amino acid. This aminoacyl tRNA complex binds reversibly to the mRNA at the initiation site by hydrogen bonding via specific complementary base pairing with its anticodon.
It occupies the P site of a ribosome; translation starts as a translation initiation complex is formed. The initiation codon is most often AUG, which codes for the amino acid methionine.
Several ribosomes attracted to the mRNA simultaneously form a polyribosome. This is possible as once a ribosome has moved past the start codon, a second ribosome can attach to mRNA, thereby increasing efficiency of translation. The binding of the mRNA forms a translational complex and elongation of the polypeptide chain as translation proceeds. Newly formed polypeptide chains then enter the rough endoplasmic reticulum lumen and fold into its secondary/tertiary/quaternary structure in the cisternae. It is then packaged into vesicles and buds off and fuses with the soft endoplasmic reticulum and then the Golgi apparatus.
- Q: Compare And Contrast Transcription And Translation
Transcription occurs in the nucleus but translation occurs in the cytoplasm and rough endoplasmic reticulum. The two processes use different components and enzymes, transcription uses transcription factors and RNA polymerase whereas translation uses ribosomes...
- Amino Acid Activation
Codons of an mRNA molecule contain genetic messages that are carried by the mRNA and they need to be translated to form the corresponding sequence of amino acids that will form the polypeptide chain and subsequently the protein. The tRNA transfers amino...
- Initiation Involves Base Pairing Between Mrna And Rrna
KEY TERMS:The Shine-Dalgarno sequence is the polypurine sequence AGGAGG centered about 10 bp before the AUG initiation codon on bacterial mRNA. It is complementary to the sequence at the 3 end of 16S rRNA. KEY CONCEPTS: An initiation site on bacterial...
- Use Of Fmet-trnaf Is Controlled By If-2 And The Ribosome
KEY TERMS:The context of a codon in mRNA refers to the fact that neighboring sequences may change the efficiency with which a codon is recognized by its aminoacyl-tRNA or is used to terminate protein synthesis. KEY CONCEPTS: IF-2 binds the initiator...
- Protein Synthesis Occurs By Initiation, Elongation, And Termination
KEY TERMS:The A site of the ribosome is the site that an aminoacyl-tRNA enters to base pair with the codon. The P site of the ribosome is the site that is occupied by peptidyl-tRNA, the tRNA carrying the nascent polypeptide chain, still paired with the...