Exam Five Flashcards
1
Q
enzymes
A
- referred as biological catalysts
- often end in “ase”
- named often based on the reaction they catalyze
2
Q
enzyme urease accepts only one specific substrate, considered:
A
absolute specificity
3
Q
enzyme alcohol dehydrogenase can oxidize many alcohols, considered:
A
relative specificity
4
Q
cofactors
A
- some enzymes need cofactors to function
- can be inorganic ions
- can be organic compounds/coenzymes
(derived from vitamins)
5
Q
the optimum pH of most enzymes is about
A
7
6
Q
the optimum pH of pepsin is about
A
1.5
7
Q
temperature optimum of most enzymes
A
typically 37 degrees celcius
8
Q
Michaelis menten enzymes
A
- has two parameters: Km and Vmax
- Km: the affinity between an enzyme and substrate
- Vmax: maximum velocity or reaction rate
9
Q
enzyme inhibitors
A
- compounds that reduce an enzyme’s activity
- IRREVERSIBLE INHIBITORS: react covalently with enzymes (ex. aspirin)
- REVERSIBLE INHIBITORS: bind to enzyme and interfere with its activity (temporary inhibitory effect)
10
Q
competitive inhibitors & noncompetitive inhibitors
A
- COMPETITIVE:
binds to the substrate binding site & also affects affinity or Km - NONCOMPETITIVE:
binds tp site different that active site & also affects the Vmax
11
Q
allosteric enzymes
A
- consists of more than one polypeptide chain
- cooperative behavior: binding of substrate to the active site that affects binding of the substrate at other subunits
- has positive and negative effectors (enhance-increase rate/reduce-slow)
12
Q
negative effectors
A
helps prevent its own overproduction
through FEEDBACK INHIBITION
13
Q
activity of some enzymes is controlled by the formation of inactive enzyme precursors:
A
- zymogens
14
Q
lipids
A
insoluble in water and found in a living system
15
Q
fatty acids
A
- have even number of carbons
- have around 12-20 carbons
- insoluble in water
