EXAM 3 Flashcards
Which part of a ribosome accepts a tRNA molecule that is attached to a growing polypeptide chain?
P site
What kind of bonds join amino acids in a polypeptide chain?
Peptide bonds
During translation, an mRNA molecule has a codon with the triplet sequence 5’-AUC-3’. Which anticodon sequence in a tRNA molecule would pair with this codon?
5’-GAU-3’
The following figure shows a mutation at position 14 in the DNA that causes valine to substitute for aspartate in the peptide chain. This is an example of a
missense mutation
Which of the following statements about transfer RNA (tRNA) is true?
Activating enzymes (aminoacyl-tRNA synthetases) link together a specific amino acid with a specific tRNA
Tetracycline, but not penicillin, is able to kill MRSA because tetracycline
inhibits protein synthesis
Which of the following would be a useful treatment for alkaptonuria?
Gene therapy that supplies an enzyme that breaks down homogentistic acid
Which of the following discoveries caused the modification of the “one gene–one protein” hypothesis to the “one gene–one polypeptide” hypothesis?
Proteins made up of two or more chains
The “adapters” that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called
transfer RNAs
RNA polymerase differs from DNA polymerase in that RNA polymerase
does not require a primer
Promoters are made of
Nucleic acids
RNA polymerase uses the _______ DNA template to synthesize a _______ mRNA.
3′-to-5′; 5′-to-3′
Errors in transcription are not as potentially harmful as errors in DNA replication because
D. Both a and b
A. many copies of the same RNA sequence are made.
B. RNA sequences have a relatively short life span.
In eukaryotes, exons are
spliced together from the original transcript
Suppose the DNA of a gene contains five motifs (A, B, C, D, and E) in that order. Motifs A, B, and D are located in introns, while motifs C and E are located in exons. What is the order of the motifs in the pre-mRNA transcribed from that sequence?
ABCDE
Note: Pre-mRNA contains both introns and exons, and is ABCDE, where as mRNA contains only exons and would be CE.