Which one of the following statements about transfer RNA (tRNA) molecules is true?

Introduction / Context:
This question tests your knowledge of transfer RNA, a key player in protein synthesis. tRNA molecules act as adaptors between nucleic acid information and amino acid sequences. Understanding their structure and function is essential for grasping how genetic information is translated into proteins.

Given Data / Assumptions:

• tRNA molecules participate in translation, the process that builds polypeptides from messenger RNA.
• Each option describes a possible property of tRNA.
• We seek the one statement that accurately describes tRNA in most cells.
• The context is general, applying to typical cellular biology.

Concept / Approach:
tRNA molecules are short, single stranded RNA molecules that fold into a characteristic cloverleaf shape. Each tRNA has an anticodon sequence that base pairs with a codon on messenger RNA and a specific attachment site for an amino acid. Different tRNA species carry different amino acids, and cells have many types of tRNAs, not just four. tRNA molecules are not double stranded like DNA. By recalling these properties, we can identify the correct statement.

Step-by-Step Solution:
Step 1: Recall that tRNA is made of ribonucleic acid and folds into a cloverleaf structure, which means it is single stranded but extensively base paired within itself.Step 2: Each tRNA has a specific three nucleotide anticodon that pairs with a complementary codon on messenger RNA.Step 3: At the opposite end, each tRNA can be attached to a particular amino acid by an enzyme called aminoacyl tRNA synthetase.Step 4: There are many different tRNAs in a cell, often more than twenty, because there are multiple codons and amino acids to represent.Step 5: Therefore, the correct statement is that each tRNA binds a particular amino acid corresponding to its anticodon.

Verification / Alternative check:
You can verify this by reviewing the translation process. During protein synthesis, tRNAs bring specific amino acids to the ribosome by matching their anticodons with codons on the messenger RNA. The one to one relationship between a tRNA and its amino acid is central to the accuracy of protein translation.

Why Other Options Are Wrong:
Double stranded molecules similar to typical DNA: tRNAs are single stranded RNA molecules that fold back on themselves; they are not double stranded like DNA helices.
Exactly four types of tRNA: Cells have many more than four tRNA types, because they must recognize multiple codons and carry different amino acids.
All of the above: Since the first two statements are incorrect, this inclusive option cannot be true.

Common Pitfalls:
Students may confuse tRNA structure with that of DNA because both are involved in genetic processes. Another pitfall is assuming there are only four tRNAs corresponding directly to the four RNA bases, which ignores the complexity of codons and amino acids. Remember that there are many codons and at least one tRNA for each amino acid.

Final Answer:
The correct statement about transfer RNA is that Each tRNA binds a particular amino acid corresponding to its anticodon.