One consequence of the rotation of DNA is illustrated In the two-domain model for transcription, as RNA polymerase moves with respect to the double helix, it generates positive supercoils (more tightly wound DNA) ahead of it and leaves negative supercoils (partially unwound DNA) behind it. For each helical turn traversed by RNA polymerase, + 1 turn is generated ahead and -1 turn behind.

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#Id: 3857

#Unit 5. Developmental Biology

Phosphorylation of RegA is mediated by sensor histidine kinases/phosphatases which either phosphorylate or dephosphorylate themselves on a histidine residue when a signal molecule binds to their sensor domain.

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#Id: 4010

#Unit 7. System Physiology – Animal

The cause of less negative RMP of SA node is that the cell membranes of the sinus fibers are naturally leaky to sodium and calcium ions.

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#Id: 8756

#Unit 1. Molecules and their Interaction Relevant to Biology

Protein stability is the net balance of forces, which determine whether a protein will be in its native folded conformation or a denatured state.

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#Id: 2673

#Unit 7. System Physiology – Animal

Positive charge forces cations such as Mg++ and Ca++ to diffuse from the tubular lumen through the paracellular space and into the interstitial fluid.

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#Id: 1060

#Unit 5. Developmental Biology

CONSTANS (CO) belongs to the Zinc finger TF family Activates flowering in response to long photoperiods