How nucleotide stores the information of specific amino acid in codon
Sample Solution
Nucleotides don't directly store the information of specific amino acids. Instead, they act like a three-letter code called a codon that the cell uses to look up the corresponding amino acid in a reference table known as the genetic code.
Here's a breakdown of the process:
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DNA Structure: DNA is made up of a chain of nucleotides, each containing a sugar, a phosphate group, and a nitrogenous base (adenine (A), guanine (G), cytosine (C), or thymine (T)).
Full Answer Section
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Codons: The sequence of three nucleotides in DNA (or mRNA, a copy of DNA used for protein synthesis) forms a codon. There are 64 possible codon combinations (4 bases x 4 bases x 4 bases).
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Genetic Code: The genetic code is a universal table that translates each codon sequence into a specific amino acid. For example, the codon AUG always codes for the amino acid methionine, while UUU codes for phenylalanine.
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Transfer RNA (tRNA): These specialized molecules act as adapters. Each tRNA has an anticodon (a three-base sequence complementary to a specific codon) on one end and an attachment site for a specific amino acid on the other end.
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Translation: During protein synthesis, ribosomes read the mRNA codon by codon. A tRNA molecule with an anticodon complementary to the current codon binds to the ribosome. The tRNA also carries its specific amino acid.
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Amino Acid Chain Formation: The ribosome facilitates the formation of a peptide bond between the amino acid carried by the bound tRNA and the growing polypeptide chain. The tRNA then detaches and fetches another amino acid based on its anticodon, allowing the process to continue codon by codon until the entire protein is synthesized.
Key Points:
- The order of nucleotides in a codon determines the amino acid it specifies.
- The genetic code is a universal "instruction manual" used by all living things.
- tRNA molecules act as interpreters, matching codons to their corresponding amino acids.