Lab 15 Flashcards
large organic molecules
proteins
subunits that make up a protein
amino acids
Amino acids bond together by _____ forming a small chain (_____) or a larger molecule (______).
peptide bonds, peptide, polypeptide
Bacteria can hydrolyze the _____ or ______ to release amino acids
peptides, polypeptides
used primarily in anabolic reactions
amino acids
large protein molecules, such as _____, are hydrolyzed by _____, and the smaller products of hydrolysis are transported into the cell.
gelatin, exoenzymes
_______ dissolves in warm water (_____), solidifies (gels) when cooled below _____, and liquefies (sols) when heated to _____.
Nutrient gelatin, 50 C, 25 C, 25 C
exoenzyme that hydrolyzes gelatin
gelatinase
protein in milk
casein
consists of skim milk and the indicator litmus
litmus milk
Litmus milk medium is opaque due to ____ in colloidal suspension and the litmus is ____.
casein, blue
hydrolysis of the milk proteins
peptonization
Litmus milk is also used to detect _____, because litmus turns pink in the presence of acid.
lactose fermentation
Excessive amounts of acid will cause ______ of the milk
coagulation (curd formation)
_________ will result in an alkaline (purple) reaction of litmus milk.
catabolism of amino acids
Some bacteria can _____, causing the litmus indicator to turn white in the bottom of the tube.
reduce litmus
waste product of protein digestion and is excreted in the urine
urea
enzyme that liberates ammonia from urea
urease
contains peptone, glucose, urea, and phenol read. The pH of the prepared medium is 6.8 (phenol red turns yellow)
urea agar
During incubation in urea agar, bacteria possessing urease produce _____, which _____ the pH of the medium, turning the indicator _____ at pH ____
ammonia, raises, fuchsia, 8.4
After hydrolysis, the pH of urea agar is _____
high (basic)
After hydrolysis, gelatin will _____ at 22 C
liquefy
