1、PROTEIN SYNTHESISFour Main Stages1. Synthesis of Amino acid2. Transcription (formation of RNA)3. Amino acid activation4. TranslationSynthesis of Amino acidIN PLANT occurs in mitochondria and chloroplastsSynthesis of Amino acidNITRATE AMINO GROUPSREDUCTIONAMINO ACIDSCOMBINATION WITH A CARBON SKELETON
2、Synthesis of Amino acidIN ANIMAL amino acids are mostly obtained through their food supply some amino acids can be synthesized inside their bodyTRANSCRIPTIONTCATG A TT AAG T AC A A A T Transcription takes place inside the nucleus.Part of a DNA unwinds.AG T AC A A A T AGCUGACGGUUUOnly one strand acts
3、 as a template.AG T AC A A A T AGCUGACGGUUUExposed base attracts complementary RNA.RNA POLYMERASEAG T AC A A A T AGCGACGGUUU UThe enzyme RNA polymerase adds one complementary RNA nucleotide to the existing one.AG T AC A A A T AGCGACGGUUU UThe enzyme RNA polymerase moves along the DNA. AG T AC A A A
4、T GCGACGGUUU UAThe enzyme RNA polymerase moves along the DNA. AG T AC A A A T GCGACGUUGU UAComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T GCGACGUGU UAUComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T GCGACGGU
5、 UAU UComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T GCGACGGU UAU UAComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T GCGCGGU UAU UA UComplementary RNA nucleotide is added to the growing chain of mRNA one by o
6、ne.AG T AC A A A T GGCGGU UAU UA U CComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T GGCGGU UAU UA U CComplementary RNA nucleotide is added to the growing chain of mRNA one by one.AG T AC A A A T UCAUG A UUAmRNACYTOLPLASMmRNA leaves the nucleus through th
7、e nuclear pore.NUCLEOPLASMNuclear poreAG T AC A A A T UCAUG A UUAmRNAmRNA leaves the nucleus through the nuclear pore.CYTOLPLASMNUCLEOPLASMUCAUG A UUAmRNACODONCODONCODONAMINO ACID ACTIVITIONA A ULeucineAC UAsparticAcidAUGThreonineTRANSFER RNAAMINO ACIDSA A ULeucineAC UAsparticAcidAUGThreonineAmino a
8、cids combine with the tRNAs using the energy from the splitting of ADP.A A ULeucineAC UAsparticAcidAUGThreonineAmino acids combine with the tRNAs using the energy from the splitting of ADP.A A ULeucineAC UAsparticAcidAUGThreonineANTICODONTRANSLATIONUCAUG A UUAmRNACYTOLPLASMUCAUG A UUAA A ULeucineAC
9、UAsparticAcidRIBOSOMEmRNA attaches to the ribosome.UCAUG A UUAA A ULeucineAC UAsparticAcidComplementary anticodon of the tRNA is attracted to the codon of the mRNA .UCAUG A UUAA A ULeucineAC UAsparticAcidAUGThreonineComplementary anticodon of the tRNA is attracted to the codon of the mRNA .UCAUG A U
10、UAA A ULeucineAC UAsparticAcidAUGThreoninePeptide bond forms between the two adjacent amino acids.UCAUG A UUAA A ULeucineAC UAsparticAcidAUGThreonineRibosome moves along the mRNA. Another complementary tRNA is attracted to the codon. The first tRNA is released back to cytoplasm.UCAUG A UUAA A ULeuci
11、neAC UAsparticAcidAUGThreonineAmino acid is linked to the previous amino acids with peptide bond.UCAUG A UUAA A ULeucineAC UAsparticAcidAUGThreonineA tripetide is formed. UCAUG A UUAA A UAC UAUGLeucineAsparticAcidThreoninemRNA and tripeptide are released to cytoplasm. SCIENCE SECTIONCURRICULUM DEVELOPMENT INSTITUTEEDUCATION DEPARTMENT
