genetic code 3.pptx for your science presentation this is what you need to download this file
- 2. TheGeneticCode The nucleotide (base) sequence of an mRNA molecule is the informational part of such a molecule. This base sequence in a given mRNA determine the amino acid sequence for the protein synthesized under that mRNA’s direction.
- 3. There are four nucleotides (base) in RNA: Adenine, Guanine, Cytosine, Uracil. There are 20 amino acids that supports our body. 4X4X4=64 possible combinations. Codon= a three-nucleotide sequence in an mRNA that codes for a specific amino acid. Genetic Code= is the assignment of 64 mRNA codons to specific amino acids (or stop signals). Marshall Nirenberg and Har Gobind Khorana.
- 5. RemarkablefeaturesofGeneticCodes The genetic code is highly degenerate. There is a pattern to the arrangement of synonyms in the genetic code table. The genetic code is almost universal. An initiation codon exists.
- 6. AnticodonsandtRNAMolecules All tRNA molecules have the same general shape, and this shape is crucial on how they function. The general two-dimensional “cloverleaf” shape of tRNA by the molecule’s folding and twisting into regions of parallel strands and regions of hairpin loops.
- 7. TwofeaturesofthetRNAstructureareofparticularimportance: The 3’ end of the open part of the cloverleaf structure is where an amino acid becomes covalently bonded to the tRNA molecule through an ester bond. The loop opposite the open door of the cloverleaf is the site for a sequence of three bases called an anticodon– is a three-nucleotide sequence on a tRNA molecule that is complementary to a codon on an mRNA molecule.
- 9. TRANSLATION:PROTEINSYNTHESIS Translation– is the process by which mRNA codons are deciphered and a particular protein molecule is synthesized. The substances needed for the translation phase of Protein synthesis are: mRNA molecules, tRNA molecules, aamino acids, ribosomes, and a number of enzymes.
- 10. Ribosomes is an rRNA that serves as the site for translation phase of protein synthesis. Ribosomes are composed of two subunits called the small and large subunits. TRANSLATION:PROTEINSYNTHESIS
- 11. The smaller subunit--reads mRNA codes. The larger subunit--assembles the polypeptide chain from amino acids. Each subunits contains rRNA The active site is the larger subunit. The enzyme is ribozyme. TRANSLATION:PROTEINSYNTHESIS
- 14. 2.Initiation
- 15. 3.Elongation
- 16. 4.Termination
- 17. 5.Post-TranslationProcesses Gives the protein the final form it needs to be fully functional. the second hydrolysis reaction releseas the polypeptide chain to tRNA carrier. the formation of disulfide bridges may occur.