Trivalent and pentavalent arsenic produce different effects on cells, yet there is little distinction between the two forms of arsenic when discussing signs and symptoms of poisoning. Why?

(8). Na2EDTA is actually used in the lab because ____   a.  it does not lose its crystalline water component. it loses its crystalline water component thus makes a constant composition. it is a base which is needed to react with metal ions. it is easier to be dissolved in water than EDTA. it is only commercially available EDTA-related reagent.      (9). Which of the following statement is true  ? ____    a.  EDTA is an amino acid.    Usually we use the acidic form of EDTA for the lab use. EDTA stands for “ Ethyldimertetraacid” EDTA forms complexes with metal ions in a variable stoichiometry. EDTA usually offers 5 binding sites for metal ions. None of the above   (10).  “The determination of CuO ore sample” lab is a ____     a. Acid-base titration        b. complexometric titration         c. iodometry          d. gravimetry           e. iodimetry

Explain why some agents such as iron may display both beneficial and harmful effects.

Which of the following terms describes when weak forces are broken, drastically changing the shape of proteins or other large macromolecules? Dehydration Denaturing Dissolving None of the choices. Hydrolysis

Why are there two bands in the first lane and only one band in the second lane?

Lemon juice has a pH around 2.5. Milk has a pH around 6.5-7. Which of the following statements about these two liquids is true? Lemon juice has a higher concentration of hydrogen ions compared to milk Milk has a lower concentration of hydroxyl ions compared to lemon juice Milk has a higher concentration of hydrogen ions compared to lemon juice The concentration of water in lemon juice and milk is identical

The pH of a solution is 7, what is the H+ concentration?   Group of answer choices   1 x 10e-7 M 1 x 10e-3 M 1 x 10e-8 M 1 x 10e-9 M

Which of the following statements about pH is (are) true: pH is a measure of free hydrogen ion concentration none of these are true both of these are true An increase in hydrogen ion concentration means a decrease in pH scale units

The reactive sites of FAD are: O2 N atoms O 2 C atoms O 1 N atom O 2 C atoms

Phosphoglycerides are composed of: (select all that apply)   Group of answer choices sphingosine aminoalcohol phosphate group fatty acids glycerol monosaccharide