Number the following steps of protein synthesis in the order in which they occur, starting with 1 and ending with 9.
a. _____The stop codon is reached, and the polypeptide is released. 
b. _____The small ribosomal subunit finds the start codon, and the large ribosomal subunit joins. 
c. _____The end of the gene is reached, and the pre-mRNA is released and then edited. 
d. _____The transcription factor binds the promoter. 
e. _____The protein is folded and modified to become functional. 
f. _____ RNA polymerase builds the mRNA transcript. 
g. _____mRNA and initiator tRNA bind the small ribosomal subunit. 
h. _____ New tRNAs are brought into the A site successively, and the peptide chain of the tRNA in the P site is joined to the amino acid of the tRNA in the A site.
i. ______mRNA exits the nucleus via a nuclear pore.

Verified step by step guidance

1. Step 1: Begin by understanding that protein synthesis involves two main processes: transcription and translation. Transcription occurs in the nucleus, while translation occurs in the cytoplasm.
2. Step 2: Identify the steps related to transcription. These include: (d) The transcription factor binds the promoter, (f) RNA polymerase builds the mRNA transcript, and (c) The end of the gene is reached, and the pre-mRNA is released and then edited.
3. Step 3: Recognize that after transcription, the mRNA exits the nucleus. This corresponds to step (i) mRNA exits the nucleus via a nuclear pore.
4. Step 4: Transition to translation, which begins with (g) mRNA and initiator tRNA binding the small ribosomal subunit, followed by (b) The small ribosomal subunit finding the start codon, and the large ribosomal subunit joining.
5. Step 5: Complete translation by ordering the remaining steps: (h) New tRNAs are brought into the A site successively, and the peptide chain of the tRNA in the P site is joined to the amino acid of the tRNA in the A site, (a) The stop codon is reached, and the polypeptide is released, and finally (e) The protein is folded and modified to become functional.

Key Concepts

Protein Synthesis

Protein synthesis is the biological process through which cells generate proteins. It involves two main stages: transcription, where DNA is converted into mRNA, and translation, where mRNA is decoded by ribosomes to assemble amino acids into a polypeptide chain. Understanding this process is crucial for sequencing the steps correctly.

Transcription

Transcription is the first step of protein synthesis, where the DNA sequence of a gene is copied into mRNA. This process begins when RNA polymerase binds to the promoter region of the gene, leading to the synthesis of a pre-mRNA strand. The pre-mRNA undergoes editing before it exits the nucleus, making it essential to recognize its role in the overall sequence of protein synthesis.

Translation

Translation is the second stage of protein synthesis, occurring in the ribosome, where mRNA is translated into a polypeptide chain. This process involves the binding of tRNA molecules to the mRNA, facilitating the addition of amino acids to the growing polypeptide. Key steps include the initiation of translation, elongation through successive tRNA binding, and termination upon reaching a stop codon, which is vital for understanding the order of events in the question.