#Question id: 28688
#Unit 2. Cellular Organization
Ca2+ is released into the cytosol from the ER lumen through the operation of____
#Question id: 4010
#Unit 3. Fundamental Processes
In a cell that produces only one type of protein, which of the following statements about the relationship between hnRNA and mRNA is true?
#Question id: 4296
#Unit 3. Fundamental Processes
Normally, a stop codon is required to release the ribosome from an mRNA but what happens to a ribosome that initiates translation of an mRNA fragment that lacks a termination codon. The Ribosome stalled at broken part of mRNA. In prokaryotic cells, such stalled ribosomes are rescued by the action of a chimeric RNA molecule that is part tRNA and part mRNA, appropriately called a tmRNA. What is sequence of events of this rescue process.
A. Translocation of the peptidyl-SsrA RNA results in the release of the broken mRNA
B. the SsrAAla–EF-Tu–GTP complex binds to the A-site of the ribosome and participates in the peptidyl transferase reaction
C. portion of the SsrA RNA acts as an mRNA and encodes 10 codons followed by a stop codon
D. the protein encoded by the incomplete mRNA is fused to a 10-amino-acid “peptide tag” at its carboxyl terminus, and the ribosome is recycled. Interestingly, the 10-amino-acid tag is recognized by cellular proteases that rapidly degrade the tag and the truncated polypeptide to which it is attached
#Question id: 19350
#Unit 12. Applied Biology
#Question id: 4065
#Unit 3. Fundamental Processes
The NtrC protein from E. coli
a. is a σ54 RNA polymerase. b. stimulates transcription of the glnA gene.
c. is activated by a protein kinase called NtrB.
d. binds both to an enhancer site upstream of the glnA gene and to RNA polymerase.
e. has ATPase activity.