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. Understand that each codon in mRNA consists of 3 nucleotides.
2. Calculate the rate of mRNA synthesis in terms of codons per second by dividing the rate of nucleotide synthesis (60 nucleotides/second) by 3.
3. Recognize that the rate of translation by a ribosome should not exceed the rate of mRNA synthesis in codons per second to avoid collisions.
4. To find the time required to translate an mRNA containing 1800 codons, divide the total number of codons (1800) by the maximum rate of translation in codons per second.
5. Express the time in seconds, which will give the duration needed for the ribosome to translate the entire mRNA.

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 transcription machinery and ribosomes.

Codons and Amino Acids

A codon is a sequence of three nucleotides in mRNA that corresponds to a specific amino acid or a stop signal during protein synthesis. Since there are 1800 codons in the given mRNA, this means that the ribosome will need to translate 1800 amino acids to produce the complete protein encoded by that mRNA.

Rate of Translation

The rate of translation refers to how quickly a ribosome can synthesize a polypeptide chain, typically measured in amino acids per second. To avoid overtaking RNA polymerase, the ribosome's translation rate must be equal to or less than the rate of transcription, which is given as 60 nucleotides per second, translating to a maximum of 20 amino acids per second, since each codon consists of three nucleotides.