BIOCHEMISTRYANDMOLECULARBIOLOGYmRNA----Template for protein synthesisConsequences of altering the nucleotide sequence:a. Silent mutation: The codon containing the changedbase may code for the same amino acid.b. Missense mutation: The codon containing the changedbase may code for a different amino acid .c. Nonsense mutation: The codon containing the changedbase may become a termination codon.Department of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Consequences of altering the nucleotide sequence: a. Silent mutation: The codon containing the changed base may code for the same amino acid. b.Missense mutation: The codon containing the changed base may code for a different amino acid . c. Nonsense mutation: The codon containing the changed base may become a termination codon. mRNA-Template for protein synthesis
BIOCHEMISTRYANDMOLECULARBIOLOGYUAA(Termination codon)Nonsense mutationUCASilent mutation( codon for serine)MissensemutationCCAUCU(Codon for proline)(Codonfor serine)Possibleeffects ofchanginga single nucleotidebaseinthecodingregion ofan mRNAehainDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY UAA (Termination codon) UCA ( codon for serine) CCA (Codon for proline) UCU (Codon for serine) Nonsense mutation Silent mutation Missense mutation Possible effects of changing a single nucleotide base in the coding region of an mRNA chain
BIOCHEMISTRYANDMOLECULARBIOLOGYRibosome---The site for synthesis ofproteinComponent: rRNA plus many kinds of proteinStructure and function : Formed by largesubunit and small subunit, large subunit haspeptidyl transferase activity.> Small subunit: Binding mRNA, fMet-tRNA(Prokaryote) or Met-tRNA (Eukaryote)Department of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Component：rRNA plus many kinds of protein Structure and function ： Formed by large subunit and small subunit, large subunit has peptidyl transferase activity. ➢ Small subunit: Binding mRNA, fMet-tRNA (Prokaryote) or Met-tRNA (Eukaryote) Ribosome-The site for synthesis of protein
BIOCHEMISTRYANDMOLECULARBIOLOGYRibosome---The site for synthesis ofprotein>Large subunit:(1) Donor site: Also called P site (peptidyl site) :Binding peptidyl-tRNA(2)Acceptor site: Also called A site (aminoacyl site)accept aminoacyl-tRNA(3)Transpeptidase: Catalyze amino acid between Psite and A site to form peptide bondDepartment of Biochemistryand Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY ➢Large subunit: (1) Donor site: Also called P site（peptidyl site）： Binding peptidyl-tRNA (2)Acceptor site: Also called A site (aminoacyl site) accept aminoacyl-tRNA (3)Transpeptidase: Catalyze amino acid between P site and A site to form peptide bond. Ribosome-The site for synthesis of protein
Ribosomal RNA5'end03'endOalace营
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY