Protein Synthesis Process: Understanding the Molecular Mechanism
What are the key steps involved in protein synthesis?
1. DNA unwinds and unzips.
2. RNA polymerase binds to the promoter.
3. mRNA is synthesized.
4. mRNA leaves the nucleus.
5. Ribosomes attach to the mRNA.
6. tRNA brings amino acids.
7. Polypeptide chain formation.
8. Protein synthesis termination.
Choose the correct option:
A. Step 3: mRNA is synthesized
B. Step 6: tRNA brings amino acids
C. Step 8: Protein synthesis termination
Answer:
A. Step 3: mRNA is synthesized
Protein synthesis is a fundamental process in biological systems that involves the creation of proteins from amino acids based on the information encoded in DNA. The process of protein synthesis can be broken down into several key steps.
Key Steps in Protein Synthesis:
1. Transcription: DNA unwinds and unzips, and RNA polymerase binds to the promoter region of the gene. The enzyme then synthesizes a complementary mRNA strand using one of the DNA strands as a template.
2. mRNA Synthesis: The mRNA molecule is synthesized by RNA polymerase and carries the genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm.
3. Translation: The mRNA leaves the nucleus and attaches to ribosomes in the cytoplasm. The ribosome reads the mRNA in sets of three nucleotides (codons) and tRNA molecules bring specific amino acids corresponding to the codons.
4. Polypeptide Chain Formation: The ribosome catalyzes the formation of peptide bonds between the amino acids brought in by tRNA molecules, leading to the elongation of the polypeptide chain.
5. Protein Synthesis Termination: The process continues until a stop codon on the mRNA is reached, signaling the termination of protein synthesis. The completed polypeptide chain is released from the ribosome.
Understanding the molecular mechanism of protein synthesis is crucial for unraveling the complexities of cellular processes and gene expression.