Question

A protein has a pl 4.5, which of the following is incorrect about the protein the protein is negatively charged in a buffer of pH> 7 B. the protein can be considered neutral in a buffer of pH 45 C addition of strong base will make the protein of more positively charged D. the pl of the protein will decrease if the pH salution increases. E. the protein will be least soluble in a buffer of pHe4.5 3. Which of the following can affect the separation of proteins by electrophoresis A difference of proteins in pl B. difference in pH of solvent (or media) C. difference in charge of proteins D. difference in sizes of proteins E. All above 4. Which chemical bond labeled in the structure below is called a peptide bond A. A; B. B; C. C E.E R2 D H Given amino acids A, M, N and K, How many kinds of pentapeptides could be possibly made 5. E. none of these D, 400 C, 80, A. 4, B, 20 numbers

Answer 1

answer:1) pI,pH(I),IEP all are nomenclature to represent the isoelectronic point of a molecule where it carries no net charge below it, it will carry a negative charge and above it, it will carry a positive charge

so A is an incorrect statement because it carries a positive charge at pH>7

2) E is the correct means all the above are collect

In electrophoresis charged molecules are transported through a solvent by an electrical field. And for protein separation, it depends on the all the given factors A, B, C, D

3)D is the correct option because a peptide bond is a like amide bond (R-CO-NH-R), formed by condensation type of reaction in which NH₂ and -COOH group of two amino acid combine and form peptide bond and H₂O as side product