In response to a depolarizing stimulus, some of the voltage-gated Na+ channels open and Na+ enters the cell and the membrane is brought to its threshold potential (approximately −55 mV)

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#Id: 390

#Unit 2. Cellular Organization

Of the 147 bp of DNA included in the structure, the histone-fold regions of the H3.H4 tetramer interact with the central 60 bp.

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#Id: 3599

#Unit 3. Fundamental Processes

The third base of each codon plays a lesser role in specifying an amino acid than the first two.

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#Id: 5819

#Unit 7. System Physiology – Animal

The renal epithelial cells express the enzyme 11β-HSD2, which prevent cortisol from activating mineralocorticoid receptors.

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#Id: 6028

#Unit 3. Fundamental Processes

RFC is a clamp loader that catalyzes the loading of PCNA onto DNA. It binds to the 3’ end of the DNA and uses ATP hydrolysis to open the ring of PCNA so that it can encircle the DNA.

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#Id: 4605

#Unit 13. Methods in Biology

Other dyes that bind to DNA and allow for similar types of cell cycle analysis include DAPI, Hoechst 33342, and 7-aminoactinomycin D (AAD).