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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rRNA, ribosome
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DNA, nucleotide
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mRNA, protein
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tRNA, amino acid
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Detailed explanation-1: -tRNAs bring their amino acids to the mRNA in a specific order. This order is determined by the attraction between a codon, a sequence of three nucleotides on the mRNA, and a complementary nucleotide triplet on the tRNA, called an anticodon. This anticodon also specifies the particular amino acid that the tRNA carries.
Detailed explanation-2: -genetic code expression … three unpaired nucleotides, called an anticodon. The anticodon of any one tRNA fits perfectly into the mRNA codon that codes for the amino acid attached to that tRNA; for example, the mRNA codon UUU, which codes for the amino acid phenylalanine, will be bound by the anticodon AAA.
Detailed explanation-3: -The first base of the anticodon in 5’-3’ direction binds with the third base in codon (reading in 5’-3’ direction). Thus, if the base sequence in codon of mRNA is 5’-AUG-3’, the complementary anticodon will be3’-UAC-5’ or 5’-CAU-3’.
Detailed explanation-4: -There are three places on the ribosome where tRNAs bind: the A, P, and E site. The A site accepts an incoming tRNA bound to an amino acid. The P site holds a tRNA that carries a growing polypeptide (the first amino acid added is methionine (Met)).