RNA & PROTEIN SYNTHESIS Making Proteins Using Directions From DNA
RNA & Protein Synthesis v Nitrogenous bases in DNA contain information that directs protein synthesis v DNA remains in nucleus v in order to get its instructions translated into proteins, it must send its message to the ribosomes, where proteins are made v chemical used to carry this message is mrna 3/9/17 DNA, RNA, & Protein Synthesis 2
Protein Synthesis v Protein functions v Control biochemical pathways within cell v Direct synthesis of lipids, carbohydrates, & nucleotides v Responsible for cell structure & movement 3/9/17 DNA, RNA, & Protein Synthesis 3
Transcription: mrna Synthesis v transcription process by which molecule of DNA is copied into a complementary strand of RNA v During transcription, rna attaches to special places on DNA molecule, separates 2 strands of double helix, & synthesizes a mrna strand 3/9/17 DNA, RNA, & Protein Synthesis 4
Transcription: mrna Synthesis 3/9/17 DNA, RNA, & Protein Synthesis 5
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Transcription: mrna Synthesis v Messenger RNA (mrna) type of Rna that carries genetic information from DNA in nucleus out to ribosomes in cytoplasm v codon 3-nucleotide sequence on mrna that codes for an amino acid 3/9/17 DNA, RNA, & Protein Synthesis 7
Transcription: mrna Synthesis v codon 3-nucleotide sequence on mrna that codes for an amino acid v Each codon specifies a particular amino acid that is to be placed in the polypeptide chain v More than 1 codon for each amino acid 3/9/17 DNA, RNA, & Protein Synthesis 8
20 types of amino acids 3/9/17 DNA, RNA, & Protein Synthesis 9
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64 codons code for the 20 types of amino acids & for stop 3/9/17 Biology: DNA & RNA 11
Transcription: mrna Synthesis transcrip8on involves transferring of DNA code to mrna DNA can t leave the nucleus; mrna can 3/9/17 DNA, RNA, & Protein Synthesis 12
What is the Amino Acid Sequence? What amino acids go into the numbered posi8ons? 3/9/17 DNA, RNA, & Protein Synthesis 13
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What is the Amino Acid Sequence? Answers 3/9/17 DNA, RNA, & Protein Synthesis 15
Translation: Protein Synthesis v translation process in which a message carried by mrna is decoded into a polypeptide chain (protein) 3/9/17 DNA, RNA, & Protein Synthesis 16
Translation: Protein Synthesis v transfer RNA (trna) type of RNA that carries amino acids to ribosomes where amino acids are joined together to form polypeptides 3/9/17 DNA, RNA, & Protein Synthesis 17
Translation: Protein Synthesis v anticodon 3-nucleotide sequence in trna that base pairs with complementary sequence in mrna during protein synthesis trna molecule 3/9/17 DNA, RNA, & Protein Synthesis 18
Translation: Protein Synthesis v Proteins made by stringing amino acids together to form long chains called polypeptides 3/9/17 DNA, RNA, & Protein Synthesis 19
3 Stages of Translation 1. Initiation v Start AUG (Methionine) v 5 End to 3 End 2. Elongation v Creating dipeptides, polypeptides, tertiary, & finally protein structure 3. Termination v Ending of sequence in UAA, UAG, or UGA (codes for stop) 3/9/17 DNA, RNA, & Protein Synthesis 20
Translation: Initiation 3/9/17 DNA, RNA, & Protein Synthesis 21
Translation: Elongation 3/9/17 DNA, RNA, & Protein Synthesis 22
Translation: Termination 3/9/17 DNA, RNA, & Protein Synthesis 23
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OVERVIEW v v v protein created is determined by base arrangement in DNA. DNA transfers this information to mrna, which carries the code to ribosomes where trna decodes it. trna anticodons base pair with mrna s codons. Then rrna forms peptide bonds between amino acids to form protein. Process is broken down into 2 sub-processes: 1. Transcription v process through which DNA transfers code to mrna v takes place in nucleus 2. Translation v process through which mrna is decoded & forms a protein v takes place at a ribosome Remember: transcription makes mrna & translation makes polypeptide chain (of amino acids) which form proteins 3/9/17 DNA, RNA, & Protein Synthesis 27
Roles of Different RNA Types v mrna messenger; Made by DNA to carry out DNA s plans & takes massages from nucleus to ribosomes v trna- interpreter; carries amino acids & acts as delivery service for Amino Acids to the ribosomes v rrna- meeting center or construction site; Place where amino acids are arranged & built into proteins 3/9/17 DNA, RNA, & Protein Synthesis 28
RNA & Protein Synthesis 3/9/17 DNA, RNA, & Protein Synthesis 29
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