Correct statement about two striking structural changes are seen in the enzyme upon isomerization from the closed to the open complex;

A. First, the pincers at the front of the enzyme clamp down tightly on the downstream DNA.

B. Second, there is a major shift in the position of the amino-terminal region of s. When not bound to DNA, s region 3.2 lies within the active center cleft of the holoenzyme, blocking the path that, in the open complex, is followed by the template DNA strand.

C. In the open complex, region 1.1 shifts some 50 A˚ and is now found on the outside of the enzyme, allowing the DNA access to the cleft.

D. Region 1.1 of s is highly negatively charged ( just like DNA).

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#Question id: 24330

#Unit 4. Cell Communication and Cell Signaling

Ions, low-MW precursors of cellular macromolecules, products of intermediary metabolism, & small intracellular signaling molecules can pass from cell to cell through_______?

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#Question id: 24331

#Unit 4. Cell Communication and Cell Signaling

Select the CORRECT combination by matching the junctions with their principal CAMs or adhesion receptors.

Junctions	Principal CAMs or Adhesion receptors
1. Tight junctions	a. Integrins
2. Gap Junctions	b. Occludin
3. 3-D adhesions	c. Connexin
4. Plasmodesmata	d. Undefined

TLS Online TPP Program

#Question id: 24431

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following option is correct regarding the ATP Synthase

1. ATP Synthase Has Two Functional Domains, Fo and F1

2. It Catalyzes the formation of ATP from ADP and Pi, driven by the flow of protons from the P to the N side of the membrane.

3. ATP synthase produces ATP as protons diffuse back through it from the lumen into the stroma.

4. The molecular structure of the mitochondrial ATP synthase has been determined by X-ray crystallography.

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#Question id: 24432

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is oligomycin sensitive part of ATP Synthase

TLS Online TPP Program

#Question id: 24433

#Unit 1. Molecules and their Interaction Relevant to Biology

Mitochondrial F1 has nine subunits of five different types, with the composition

TLS Online TPP Program

#Question id: 24434

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct order of proton-driven rotation of the c ring