Controlling the rates of transcription and translation is important in bacteria to avoid collisions between ribosomes and RNA polymerases. Calculate what the maximum rate of translation by a ribosome in a bacterial cell would have to be, in units of amino acids per second, so as not to overtake an RNA polymerase that is synthesizing mRNA at a rate of 60 nucleotides per second. How long would it take for this bacterial cell to translate an mRNA containing 1800 codons?

Verified step by step guidance

1. Step 1: Understand the relationship between nucleotides, codons, and amino acids. Each codon is composed of 3 nucleotides, and each codon corresponds to one amino acid during translation. Therefore, the rate of transcription (60 nucleotides per second) can be converted into codons per second by dividing by 3.
2. Step 2: Calculate the maximum rate of translation by a ribosome. To avoid collisions, the ribosome must translate at a rate equal to or less than the rate at which codons are produced during transcription. Use the rate of transcription (in codons per second) as the upper limit for the ribosome's translation rate.
3. Step 3: Determine the time required to translate an mRNA containing 1800 codons. Translation occurs at the rate determined in Step 2, and the total time can be calculated using the formula: \( \text{Time} = \frac{\text{Total codons}}{\text{Translation rate}} \).
4. Step 4: Substitute the values into the formula. Use 1800 codons for the total codons and the translation rate calculated in Step 2 to find the time required for translation.
5. Step 5: Ensure the units are consistent throughout the calculation. Verify that the rate of translation is in amino acids per second and the time is in seconds. This ensures the final result is accurate and meaningful.

Key Concepts

Transcription and Translation

Transcription is the process by which RNA polymerase synthesizes mRNA from a DNA template, while translation is the process where ribosomes synthesize proteins by decoding mRNA into amino acids. In bacteria, these processes are tightly coordinated to ensure efficient protein synthesis and to prevent collisions between the ribosomes and RNA polymerases.

Codons and Amino Acids

Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids during translation. Since there are 1800 codons in the given mRNA, this means that 1800 amino acids will be synthesized, with each codon directing the addition of one amino acid to the growing polypeptide chain.

Rate of Synthesis

The rate of synthesis refers to how quickly transcription and translation occur. In this scenario, RNA polymerase synthesizes mRNA at 60 nucleotides per second, which translates to 20 codons per second (since each codon consists of three nucleotides). To avoid collisions, the ribosome's translation rate must not exceed this rate, ensuring that it can keep pace with mRNA synthesis.