THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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20
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4
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1
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3
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Detailed explanation-1: -Abstract. Transfer RNA (tRNA) synthetases are enzymes that attach a specific amino acid to its corresponding tRNA for protein biosynthesis at the ribosome. Organisms use up to 20 tRNA synthetases to generate aminoacyl-tRNAs, one for each of the 20 standard amino acids.
Detailed explanation-2: -Answer and Explanation: tRNAs have one amino acid attached per molecule.
Detailed explanation-3: -At one end, the tRNA has an anticodon of 3’-UAC-5’, and it binds to a codon in an mRNA that has a sequence of 5’-AUG-3’ through complementary base pairing. The other end of the tRNA carries the amino acid methionine (Met), which is the the amino acid specified by the mRNA codon AUG.
Detailed explanation-4: -Motivation: The standard genetic code translates 61 codons into 20 amino acids using fewer than 61 transfer RNAs (tRNAs).
Detailed explanation-5: -As each tRNA molecule will only carry a single amino acid, and there are 20 amino acids used by the cell to synthesize proteins, there will be exactly 20 different types of tRNA molecules in a human cell.