1.Precipitation of proteins by acids

Question 1

what happens to the primary structure during the denaturation of proteins?

Answer 1

the chain conformation of dissolved globular proteins changes into insoluble fibrous molecules, but the primary structure is not altered

Question 2

what does it mean that proteins renatured?

Answer 2

they regain its original structure, activity and solubility

Question 3

what are the most often used denaturing agents for proteins?

Answer 3

Nitric acid, sulphosalicylic acid, or trichloroacetic acid

Question 4

what are the materials needed for the denaturation by sulphosalicylic acid?

Answer 4

 Diluted blood plasma (80x dilution)
 Sulphosalicylic acid (0.8 mol/l)
 NaHCO3 (0.1 mol/l)
 Pasteur pipette

Question 5

The sulphosalicylic acid precipitation test is used for the detection of ..?

Answer 5

proteins in urine

Question 6

the protein content in urine of a healthy animal?

Answer 6

The urine of a healthy animal contains no protein or only in very small quantity.

Question 7

what is the meaning of “vera proteinurea”? and what are the symptoms?

Answer 7

when proteins from blood plasma get into the urine.

first there may be renal diseases, less frequently fever, severe hypothermia or inflammatory processes.

Question 8

what is the meaning of “proteinuria spuria”?

Answer 8

caused by proteins getting into the urine from the genital or the urinary tract, e.g. due to the inflammation of lower urinary tract.

Question 9

How would you detect proteins in urine

Answer 9

By sulphosalicylic acid or nitric acid or trichloroacetic acid