7-Precipitation Reaction of Proteins

Precipitated (pale yellow sol.)

Heat: 5 mL of 2% casein in water bath——observations

Heat causes denaturation

What can heat co to albumin?

(All white ppt)

T2- highest coagulation
T3- least precipitate

-The higher concentration of acetic acid will strongly denature the egg albumin, causing it to precipitate out of the solution due to the disruption of its structure.

T1- 1 mL egg albumin + 1 drop 0.1N Acetic acid

T2- 1 mL egg albumin + 1 drop 5N Acetic acid

T3- 1 mL egg albumin

Which is the least and highest to precipitate? Why?

Yellow ppt.

2 ml of egg albumin solution +4 ml of ethyl alcohol—————observation

No, coagulation is still visible at the tube.

2 ml of the suspension + 10 ml water———— observe

Does ppt dissolve in water?

Nacl
(NH4)2SO4

Neutral Salts

Dissolve (no ppt)

2 mL egg albumin + NaCl————-

Undissolved (cloudy)

2 mL egg albumin + (NH4)2SO4————

CuSO4
Pb(OAc)2
AgNO3

Heavy Metal salts

Yes, the salt is completely removed from the solution by the protein

Are the salts of heavy metals completely precipitated by the proteins? No

Protein would cause a process in which heavy metals precipitate; as a result of this reaction, the precipitates should be vomited out of the body.

Discuss how Precipitation of heavy metal salts can be used as a first aid to metal poisoning.

3 drops potassium ferrocyanide
3 drops 5% tannic acid
3 drops picric acid

Alkodial reagents

So that the remaining proteins present would acidify and coagulate

What is the purpose of adding HCL in Alkaloidial Reagents?

because Picric acid has antiseptic and astringent properties

Picric acid is used in the treatment of burns because it has antiseptic properties and can help prevent infection in burn wounds.

Tannic acid is used for diarrhea because it has astringent properties, which means it can help reduce inflammation and shrink mucous membranes in the intestinal tract, leading to a decrease in diarrhea symptoms.

Why is picric acid used in treatment of burns and tannic acid for diarrhea?

Quinine- used as an antimalarial medication

Caffeine- acts as a central nervous system stimulant

Cite 2 more alkoidial reagent and their effects on the human body.

Because By definition, alkaloids are aa class of basic, naturally occuring organix xompounds that contain atleast one nitrogen atom.

Why are they called alkaloidal reagents?

Protein denaturation is a process in which the native three-dimensional structure of a protein is disrupted or unfolded, leading to a loss of its biological activity.

How does denaturation of proteins take place?