what is the first step of protein synthesis?
The first step of protein synthesis is transcription. During transcription, the DNA code is transcribed into a complementary messenger RNA (mRNA) molecule. This process occurs in the nucleus of eukaryotic cells, where the DNA unwinds and an enzyme called RNA polymerase binds to the promoter region of the gene. RNA polymerase then moves along the DNA strand, synthesizing a complementary mRNA molecule by adding nucleotides according to the base pairing rules (A pairs with U, G pairs with C).
The first step of protein synthesis is transcription. In this step, the DNA code for a specific gene is copied into a molecule called messenger RNA (mRNA) by an enzyme called RNA polymerase. This occurs in the nucleus of the cell.
The first step of protein synthesis is transcription. Transcription is a process where the genetic information encoded in DNA is converted into messenger RNA (mRNA) molecules. These mRNA molecules carry the instructions from the DNA to the ribosomes, where protein synthesis will take place.
To understand how transcription occurs, let's break it down into steps:
1. Initiation: Transcription begins when an enzyme called RNA polymerase binds to a specific region on the DNA molecule called the promoter. The promoter acts as a signal for the start of transcription.
2. Elongation: Once RNA polymerase is bound, it moves along the DNA template strand, unwinding the DNA double helix and synthesizing a complementary mRNA molecule. RNA polymerase adds nucleotides one by one, creating a growing mRNA strand that is complementary to the DNA template.
3. Termination: Transcription continues until RNA polymerase reaches a signal on the DNA sequence called the terminator. The terminator signals the end of transcription, and the newly synthesized mRNA molecule is released.
After transcription, the mRNA molecule carries the genetic information from the DNA out of the nucleus and into the cytoplasm, where it will be used as a template for the next step in protein synthesis, which is translation.