,Types of RNA
} mRNA
Ø Carries information from DNA to the ribosome
Ø The coding sequence of mRNA determines the
amino acids sequence in the protein that is
produced
} tRNA
Ø Transfers a specific amino acid to a growing
polypeptide chain at the ribosome
Ø It has sites for amino acid attachment and a codon
recognition site that binds to a specific sequence on
the mRNA
3
,Types of RNA
} rRNA
Ø rRNA and protein combine in the
cytoplasm to form ribosome
Ø Is the catalytic component of
ribosomes
Ø Eukaryotic ribosomes contain 4
different rRNA molecules: 18S, 5.8S,
28S, 5S
Ø Ribosome binds to mRNA and
carries out protein synthesis
4
, Telomere shortening
} Because of the 5’-3’ direction
of the DNA polymerase, the
lagging strand cannot be
replicated to the end
Ø This will results in
Telomere shortening
} If the telomeres become too
short, the cell will undergo
apoptosis
} mRNA
Ø Carries information from DNA to the ribosome
Ø The coding sequence of mRNA determines the
amino acids sequence in the protein that is
produced
} tRNA
Ø Transfers a specific amino acid to a growing
polypeptide chain at the ribosome
Ø It has sites for amino acid attachment and a codon
recognition site that binds to a specific sequence on
the mRNA
3
,Types of RNA
} rRNA
Ø rRNA and protein combine in the
cytoplasm to form ribosome
Ø Is the catalytic component of
ribosomes
Ø Eukaryotic ribosomes contain 4
different rRNA molecules: 18S, 5.8S,
28S, 5S
Ø Ribosome binds to mRNA and
carries out protein synthesis
4
, Telomere shortening
} Because of the 5’-3’ direction
of the DNA polymerase, the
lagging strand cannot be
replicated to the end
Ø This will results in
Telomere shortening
} If the telomeres become too
short, the cell will undergo
apoptosis
