Answer:
The genetic code is a set of rules that governs how the information contained in DNA is translated into the construction of proteins. This process, known as protein synthesis, involves two main stages: transcription and translation.
1. **Transcription:** This process occurs in the cell's nucleus. Here's how it works:
- DNA contains the genetic instructions in the form of genes.
- An enzyme called RNA polymerase reads a specific gene on the DNA molecule.
- RNA polymerase creates a complementary strand of RNA, called messenger RNA (mRNA), by matching nucleotides to those on the DNA strand.
- The mRNA strand carries the genetic information from the nucleus to the cytoplasm.
2. **Translation:** This process happens in the cell's cytoplasm and involves the ribosome, mRNA, and transfer RNA (tRNA).
- The ribosome reads the mRNA in sets of three nucleotides called codons. Each codon represents an amino acid, which is a building block of proteins.
- The tRNA molecules have an anticodon that matches the mRNA codon, and each tRNA carries a specific amino acid.
- The ribosome helps the tRNA bind to the mRNA, ensuring the correct amino acid sequence is built.
- Amino acids are linked together to form a growing protein chain.
- This process continues until the ribosome encounters a stop codon on the mRNA, signaling the end of protein synthesis.
- The newly formed protein is released and folded into its functional shape.
In summary, the genetic code provides instructions for building proteins by transcribing the DNA code into mRNA, which is then translated into a sequence of amino acids. These amino acids are assembled into a specific protein with a unique structure and function, based on the sequence of codons in the mRNA. This entire process ensures that the right proteins are produced in the right quantities, essential for the proper functioning of the cell and the organism as a whole.