Why are there at least 20 tRNAs?

Question

Accepted Answer

Hello everyone. Today we have the following problem. What is the reason for the existence of at least 20 distinct types of TRN A? So let's go through each of these choices. A says that each trn A type corresponds to a specific amino acid along for accurate genetic code translation during protein synthesis. And this is actually correct and our answer. But we will see whether other options are incorrect. Choice. B says that these trn A molecules combined to multiple amino acids which reduces the need for different trn A types in the cell. Well, this is incorrect as tin A molecules are generally specific to only one ami acid. Although there may be slight flexibility due to what's known as the Wobble hypothesis. Choice D says that are is incorrect as it states multiple trn A types exist due to the redundancy in the genetic code which allows some amino acids to be encoded by multiple coons. Well, while the genetic code is redundant, it doesn't explain the need for 20 distinct amino acids. In choice D is incorrect as it states different trn A types are necessary to transport amino acids across the cell membrane for protein. Well, this is incorrect because trn A only delivers amino acids to the ribosomes during protein synthesis. Overall, I hope this helped Hanzo next time.

Why are there at least 20 tRNAs?

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Key Concepts

tRNA Structure and Function

Genetic Code and Codons

Wobble Hypothesis