Question
What are the steps involved in protein synthesis?
Responses
Active and passive transport
Diffusion and Osmosis
Replication and differentiation
Transcription and Translation
Transcription and Translation are the main steps involved in protein synthesis. Here is a brief explanation of these steps:
1. Transcription: In the nucleus of a cell, the DNA serves as the template for the synthesis of messenger RNA (mRNA). During transcription, an enzyme called RNA polymerase binds to the DNA and separates the two strands. One of the strands, known as the template strand, is used as a guide to create a complementary mRNA molecule. This process involves the addition of nucleotides, resulting in the formation of pre-mRNA.
2. RNA processing: The pre-mRNA molecule undergoes further modifications before leaving the nucleus. These modifications include the removal of non-coding regions called introns and the addition of a protective cap at the beginning (5' end) and a poly-A tail at the end (3' end) of the mRNA molecule. This processed mRNA molecule is now ready for translation.
3. Translation: Translation takes place in the cytoplasm of the cell, specifically on ribosomes. It involves the conversion of the information stored in mRNA into a sequence of amino acids, which form a protein. The process starts with the binding of mRNA to a ribosomal subunit. Then, transfer RNA (tRNA) molecules, each carrying a specific amino acid, bind to the mRNA at the ribosome. The sequence of codons (three-nucleotide sequences) on the mRNA determines the order in which the tRNA molecules bind. This results in the formation of a polypeptide chain of amino acids. Once the ribosome reaches a stop codon on the mRNA, the translation process terminates, and the newly synthesized protein is released.
These steps, transcription and translation, are essential for protein synthesis in all living organisms.