OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What happens during the first stage of protein synthesis?

1. Amino acids are activated

2. mRNA is degraded

3. The gene coding for the protein unzips

4. The ribosome assembles

The correct answer is: The gene coding for the protein unzips

During the first stage of protein synthesis, known as transcription, the gene coding for the specific protein unwinds and unzips. This process occurs in the nucleus of the cell, where the DNA double helix separates to expose the coding region of the gene. RNA polymerase then binds to the DNA template strand and synthesizes a complementary strand of messenger RNA (mRNA) by pairing RNA nucleotides with the DNA nucleotides. This step is crucial as it initiates the overall process of translation that will eventually lead to the formation of a protein. The other options relate to subsequent processes or incorrect representations of the initial stage of synthesis. For example, amino acids being activated pertains to the later stages involving tRNA; mRNA degradation is not a function of the beginning of the process, and ribosome assembly occurs later during translation after mRNA has been produced.