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LESSON # 17. PROTEIN SYNTHESIS. DNA structure. The information encoded in the DNA is used in two ways:. 1- To be copied onto a new DNA strand to duplicate the genetic information (Replication of DNA ). 2- To be copied onto the messenger RNA for the Synthesis of Proteins. DNA Replication.
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LESSON # 17 PROTEIN SYNTHESIS
The information encoded in the DNA is used in two ways: 1- To be copied onto a new DNA strand to duplicate the genetic information (Replication of DNA). 2- To be copied onto the messenger RNA for the Synthesis of Proteins.
DNA Replication Protein Synthesis
Unwind C A T T T C A A G G C C G G C G
The order in which the bases occur along the DNA strand “encodes” the information for the production of proteins. Triplets A A T G G A A C T C A C
DNA Aminoacid Chain TRIPLET Three nitrogen-containing bases in the DNA, which encode the information for one aminoacid. TRIPLET:
It is a hereditary unit consisting of a fragment of DNA that occupies a spot on a chromosome and contains the information for the synthesis of one protein. Gene: Protein I Protein III Protein II Gen I Gen II Gen III
The shapes of the nitrogenous bases allow adenine to bond only to thymine, and cytosineto bond only to guanine. Hydrogen bonds Hydrogen bonds The combinations adenine-thymine (A-T) and cytosine-guanine (C-G)are known as complementary base pairs.
DNA RNA
U A C G A U U G C A G G T A T C A C C A C G mRNA The process by which the genetic information encoded in the DNA is copied onto the messenger RNA. Transcription:
1- RNA polymeraseunwinds a region of the DNA double helix 2- RNA polymerasebegins assembling RNA nucleotides on the DNA template
4- The mRNA transcript is released from the DNA, and the DNA is rewound into its original form. 3- The mRNA transcript separates from the DNA. Meanwhile the RNA polymeraseunwinds more DNA GEN
Each coding triplet of mRNA bases, which encode for one aminoacid. Codon: triplet triplet triplet triplet
Ribosomal RNA ( rRNA ) Messenger RNA ( mRNA ) Transfer RNA ( tRNA ) rRNA + proteins mRNA mRNA tRNA tRNA Types of RNA 1- Ribosomal RNA ( rRNA ): it is structural part of the ribosomes 2- Messenger RNA ( mRNA ): It carries the instructions from the DNA to the cytoplasm for the synthesis of proteins 3- Transfer RNA ( tRNA ): Select and transport the aminoacids to be incorporated in the polypeptide chain Aminoacids
Transfer RNA (tRNA) molecules link up with aminoacids in one hand and mRNA codons on the other. Translation: The process by which information encoded in the mRNA is used to assemble a protein at a ribosome. Transfer RNA TRANSLATION Anticodon
DNA Triplet: Codon: Anticodon: mRNA tRNA
Anticodon Codon Triplet Anticodon Triplet Codon Anticodon Triplet Codon A T C G A G T A A DNA tRNA mRNA U A G A U C
Overview of Translation Aminoacid chain Ribosome mRNA Translation is the process by which information encoded in the mRNA is used to assemble a protein at a ribosome.
(Peptidyltransferase) leu thr Peptide bond met GAC GCG UAC AUG CUG CGC A bacterium can string together up to 40 amino acids per second ( 400 amino acids can be put together in 10 seconds)
Transcription: The process by which the genetic information encoded in the DNA is copied onto the messenger RNA Translation: The process by which information encoded in the mRNA is used to assemble a protein at a ribosome