Multiple Choice QuestionsWhich of the following food-stuffs contains nitrogen?
Carbohydrates
fats
Proteins
None of these
Which of the following statements is true?
Denaturation of protein changes the primary structure of protein
All proteins act as biocatalyst
C-terminal amino acid in proteins is determined by Edman degradation
The pleated sheet structure of proteins was determined by Pauling
D.
The pleated sheet structure of proteins was determined by Pauling
All proteins are not biocatalysts. Denaturation of proteins affects only secondary and tertiary structures. The most commonly used method for determining the C-terminal amino acid residue in a protein is hydrazinolysis. In this method, protein is treated with anhydrous hydrazine at 373 K when all amino acid residues except C-terminal one is converted into amino acid hydrazides. The mixture of products is subjected to chromatography. On elution the strongly basic hydrazides are retained, but the free amino acid is eluted. By identifying the free amino acid the C-terminal amino acid residue of a protein can be determined.
The first β-pleated sheet structure was proposed by ω. Astburry while a refined
version was proposed by Linus pauling and Robert corey.
Switch
