Laboratory: Proteins Flashcards
a naturally occurring, unbranched polymer in which the monomer units are amino acids
PROTEINS
a peptide in which at least 40 amino acids residues are present
PROTEINS
a peptide in which at least 40 amino acids residues are present
PROTEINS
Proteins is from the Greek word proteios, meaning ___________
preeminence
The most important of all biological substances
PROTEINS
List down the protein sources
- Milk
- Wheat flour
- Beans
- Minced beef
- Egg
the most nutritionally complete food found in nature
MILK
WHOLE MILK vs SKIM/SKIMMED MILK:
is an oil-in-water emulsion, containing its 3.9% fat dispersed as micron sized globules
WHOLE MILK
WHOLE MILK vs SKIM/SKIMMED MILK:
is made when all the cream (also called milkfat) is removed from whole milk.
SKIM/ SKIMMED MILK
WHOLE MILK vs SKIM/SKIMMED MILK:
It tends to contain around 0.1% fat
SKIM/ SKIMMED MILK
main protein in milk
Casein
is a phosphoprotein which has phosphate groups attached to the hydroxyl groups of some of the amino acids side-chain
Casein
a mixture of three similar proteins, alpha, beta and kappa caseins which form a micelle
Casein
__________ are both insoluble in water and are solubilized by the micelle surrounding them
Alpha- and beta-casein
has a hydrophilic portion is responsible for solubilizing the other two caseins by promoting the formation of and stabilizing the micelles.
kappa-casein
responsible for the white opaque appearance of milk
micelles
has an isoelectric point of pH 4.6
Calcium caseinate
What is the pH of milk?
6.6
Is the pH at which an amino acid solution has no net charge because an equal number of positive and negative charges are present.
ISOELECTRIC POINT
That pH value is known as the ________ of the protein and is generally the pH at which the protein is least soluble.
isoelectric point (IEP)
At this point, almost all amino acid molecules in a solution are present at their zwitterion form.
ISOELECTRIC POINT
is a mixture of two proteins, glutenin and gliadin
GLUTEN
It is also the composite of a prolamin and glutelin, which exist, conjoined with starch, in the endosperm of various grass-related grains.
GLUTEN
is a protein composite found in wheat and related grains, including barley and rye.
GLUTEN
_____ gives elasticity to dough, helping it rise and keep its shape and often gives the final product a chewy texture
Gluten
The principle involved in the isolation of gluten is difference in solubility. The starch is ________ in water while gluten is _____ in water.
partially soluble, insoluble
What solution is used to test the complete removal of starch, which involves the formation of blue-iodo starch complex?
Iodine solution
What keeps the protein from degrading?
Refrigeration
Detection of Nitrogen:
What color indicates no presence of Nitrogen or ammonia?
Red-red
Detection of Nitrogen:
What color indicates the presence of ammonia (NH3)gas & urine like odor (presence of Nitrogen)
Red-Blue
What color precipitation is there in the Detection of Sulfur?
White ppt. (Barium Sulfate BaSO4)
What color precipitation is there in the Detection of Phosphorus?
Yellow ppt. (NH4)3PO4.12MoO3 ammonium phosphomolybdate
Most of these reactions are catalyzed by ______so that they can proceed at the rate necessary to sustain life.
enzymes
Enzymes are ______ found in all living organisms.
proteins
In an overall reaction, ______ are not consumed but are converted back into their natural state after a reaction
enzymes
reactive site where molecular reaction takes place
Enzymes
are molecules that bind in the active site of an enzyme
Substrates
