Answer:
B. binds to the tryptophan repressor when the repressor is bound to tryptophan.
Explanation:
Bacterial genes are commonly composed of operons that are activated or deactivated depends on the needed. If the bacteria need, for example, an amino acid such as tryptophan for synthesizing proteins. An activator "turns on" the transcription that the operon has and produces the amino acid.
On the other hand, if the bacteria have a high presence of tryptophan amino acid, a repressor binds to the tryptophan operator and avoids the amino acid transcription, in consequence, constrain the tryptophan production.
We are given the balanced equation 2NaF + Ca10(PO4)6(OH)2 → Ca10(PO4)6F2 + 2NaOH. The fluorapatite is the product together with sodium hydroxide. The ions involved are (PO4) 3-, Ca 2+ and <span>F-. We add the charges and check if the sum is zero, 2*10+-3*6+-1*2 =0. the zero sum tells that the compound has zero charge or neutral</span>
The concentration of OH⁻ is first converted to pOH bu using followinf formula,
pOH = -log [OH⁻]
Putting value,
pOH = -log (0.006)
pOH = 2.221
As we know,
pH + pOH = 14
Solving for pH,
pH = 14 - pOH
Putting value of pOH,
pH = 14 - 2.221
pH = 11.779
Result:
Option-1 is the correct answer.
Assuming no other acid is in the H3PO4 mix, then
<span>a) the equation </span>
<span>2H3PO4 + 3Ba(OH)2>>3H2O+Ba3(PO3)2 </span>
<span>titration equation: </span>
<span>nb*Ma*Va=na*Mb*Vb </span>
<span>nb*molesacid=na*molesbase </span>
<span>3*75*.175/98=2*Molaritybase*.215
</span><span>0.927 mol/L</span>