MMSC490 Exam 2 Questions and Correct
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Aminoacyl tRNA synthetases are enzymes that
connect amino acids while they are held in place on ribosomes by
transfer RNAs.
attach the terminal CCA sequence to transfer RNAs.
synthesize transfer RNAs.
attach amino acids to specific transfer RNAs.
Ans: attach amino acids to specific transfer RNAs.
E. coli contains about .................... different tRNAs that code for
.................... different amino acids.
40; 20
50; 20
62; 40
62; 20
Ans: 40; 20
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Which of the following is not a common lipid modification to proteins?
Prenylation
GPI anchor addition
Glycosylation
N-myristoylation
Ans: Glycosylation
The formation of peptide bonds is catalyzed by which portion of the
bacterial ribosome?
Proteins of the large subunit
16S rRNA
23S rRNA
Proteins of the small subunit
Ans: 23S rRNA
In translation, mRNAs are read in the .................... direction, and
polypeptide chains are synthesized from the .................... ends.
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5ʹ to 3ʹ; amino to the carboxyl
5ʹ to 3ʹ; carboxyl to the amino
3ʹ to 5ʹ; carboxyl to the amino
3ʹ to 5ʹ; amino to the carboxyl
Ans: 5ʹ to 3ʹ; amino to the carboxyl
During translation, the codons on the mRNA are recognized by
complementary base pairing to the anticodon on the
ribosome.
transfer RNA.
small cytoplasmic RNA.
aminoacyl tRNA synthetase.
Ans: transfer RNA.
Translation of mRNAs starts at
the 3ʹ end of the mRNA.
a site downstream of a 3ʹ untranslated region.
a site downstream of a 5ʹ untranslated region.
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the 5ʹ end of the mRNA.
Ans: a site downstream of a 5ʹ untranslated region.
Eukaryotic ribosomes recognize and initially bind to what structure on
the mRNA?
A TATA sequence
A CCAAT sequence
The 7-methylguanosine cap
A Shine-Dalgarno sequence
Ans: The 7-methylguanosine cap
The first step in the initiation of protein synthesis is the binding of
.................... to the .................... .
the initiator tRNA; initiation codon
initiation factors; initiation codon
initiation factors; small ribosomal subunit
the small ribosomal subunit; initiation codon
Ans: initiation factors; small ribosomal subunit
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