M8 Flashcards
Physical Properties of Protein
- colorless
- tasteless
- homogenous and crystalline
- can range in shape (globular or fibrous)
- have large molecular weights
- amphoteric (acid and base)
Examples of Proteins
- Albumin
- Casein
- Gelatin
Example of protein: ?
Water soluble, heat coagulable, present in egg whites, milk, and serum.
Albumin
Example of protein: ?
Chief protein of milk, is a phosphoprotein, insoluble in water but soluble in dilute acids and alkali, non-heat coagulable protein, rich in most essential amino acids, contains traces of cysteine and cystine
Casein
Example of protein: ?
Insoluble in cold water but soluble in hot water, non-heat coagulable, derived from collagen
Gelatin
_____ is the loss of secondary, tertiary, and quarternary structured of protein by chemical or physical agent that leaves the primary structure intact.
Denaturation
Factors that cause protein denaturation
- Strong acids and bases
- Organic Solvents
- Reducing Agents
- Salt Concentration
- Heavy Metals
- Temperature Change
- Mechanical Stress
Changes in the pH can disrupt hydrogen bonds and salt bridges, causing irreversible denaturation
Strong Acids and Bases
Alcohol coagulates all types of proteins except for prolamines.
Organic Solvents
______ ______ such as 2-mercaptoethanol (HOCH2CH2SH), can break the -S-S- disulfide bonds
Reducing Agents
Changes in the ____ _____ may result in the formation of a precipitate (salting out)
Salt Concentration
_____ _____ salts like the mercuric chloride or silver nitrate, and lead precipitate protein. It denatures protein irreversibly by disrupting the salt bridges and the disulfide bonds
Heavy Metals
Heat cleaves hydrogen bonds so boiling a protein solution destroys the alpha-helical and beta-pleated sheets
Temperature Change
Stirring and grinding action may disrupt the delicate balance forced required to maintain protein structure
Mechanical Stress
