31 notecards = 8 pages (4 cards per page)
What is lactose?
A milk sugar
What are the 3 milk proteins?
The major milk substrates capable of transformation are the
1. milk sugar- lactose
Why is litmus incorporated into the medium?
To distinguish among the metabolic changes produced in milk.
Litmus is an
oxidation reduction indicator.
Litmus milk now forms an excellent differential medium in which microorganisms can
metabolize milk substrates depending on their enzymatic complement.
______ ____ now forms an excellent differential medium in which microorganisms can metabolize milk substrates depending on their enzymatic complement.
Lactose → ßgalactosidase→ GLUCOSE+ GALACTOSE
CO2↑(carbon dioxide)+H2↑(hydrogen peroxide).
separations of the curd or by the development of tracks or fissures within the curd AS GAS RISES TO THE SURFACE.
While in the oxidized state, the litmus is _____ (what color)
When the litmus accepts hydrogen from a substrate, it will become REDUCED & turn ____ or ____ colored.
white / milk
Definition of oxidized
1. To combine with oxygen; make into an oxide.
Oxidation of lactose, which produces _____ ___, butyric acid CO2↑ & H2↑ is as follows:
Lactic acid or other organic acids precipitation of milk protein caseinas CALCIUM CASEINATE to form an insoluble clot. THE CLOT IS HARD & WILL NOT RETRACT FROM THE WALL OF THE TEST TUBE.
Acid curds are
hard & will not retract from walls of test tube.
Some organisms produce rennin, an enzyme that acts on casein to form paracasein, which in the presence of calcium ions is converted to calcium paracaseinate & forms an insoluble clot. Unlike acid curd, THIS IS A SOFT SEMISOLID CLOT THAT WILL FLOW SLOWLY WHEN THE TUBE IS TILTED.
Which curd is known to be soft & semisolid and will flow slowly if tube is tilted?
Which curd is known to be hard and not retract from tube walls?
large quantities of ammonia
remains unchanged or changes to a deeper blue.
When the medium remains unchanged or turns deep blue, that reaction is indicative of the
partial degradation of CASEIN into SHORTER POLYPEPTIDE CHAINS.
Litmus milk reactions image