#Question id: 4104
#Unit 3. Fundamental Processes
Consider following statements for catalytic mechanism of RNA polymerase
A. RNA synthesis by RNA polymerase. The reaction involves two Mg2+ ions, coordinated to the phosphate groups of the incoming nucleoside triphosphates (NTPs)
B. Three Asp residues, which are highly conserved in the RNA polymerases of all species. One Mg2+ ion facilitates attack by the 39-hydroxyl group on the phosphate of the NTP; the other Mg2+ ion facilitates displacement of the pyrophosphate, and both metal ions stabilize the pentacovalent transition state.
C. About 17 bp of DNA are unwound at any given time. RNA polymerase and the transcription bubble move from left to right along the DNA as shown, facilitating RNA synthesis. Movement of an RNA polymerase along DNA tends to create negative supercoils (overwound DNA) ahead of the transcription bubble and positive supercoils (underwound DNA) behind it.
D. The RNA polymerase is in close contact with the DNA ahead of the transcription bubble as well as with the separated DNA strands and the RNA within and immediately behind the bubble. A channel in the protein funnels new NTPs to the polymerase active site. The polymerase footprint encompasses about 35 bp of DNA during elongation.
#Question id: 1053
#Unit 4. Cell Communication and Cell Signaling
Phages that can either replicate and cause cell lysis or can integrate their DNA into the host DNA are called
#Question id: 289
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following statements describes a covalent bond between Carbon and Hydrogen:
#Question id: 13186
#Unit 10. Ecological Principles
The following figure is a model of seedling establishment as a function of distance from a parent tree. Initial seed density measures the number of seeds falling to the ground. Seed survivorship measures the proportion of seeds that survive to the adult stage at each distance
This model predicts that recruitment of new individuals into the population should be
#Question id: 83
#Unit 1. Molecules and their Interaction Relevant to Biology
Which of the following is incorrect about the intramolecular cyclization reaction of glucose in solution ________.