MMSC 436 EXAM 1 QUESTIONS WITH VERIFIED
ANSWERS
When a reaction is performed in zero-order kinetics: - Answers - The rate of the reaction
is independent of the substrate concentration
Activation energy is: - Answers - Decreased by enzyemes
Examples of cofactors include: - Answers - Zn+2, Mg+2, and Ni+2
Pyridoxal phosphate and coenzyme A
Biotin and thiamine pyrophosphate
Enzyme reaction rates are increased by increasing temperatures until they reach the
point of denaturation at: - Answers - 40-60C
Which of the following is true?
A.) Enzymes force reactions to proceed in only one direction.
B.) Enzymes alter the standard free energy of the reaction
C.) Enzymes alter the equilibrium of the reaction
D.) All of the above
E.) None of the above. - Answers - None of the above
Which of the following is necessary for maximal enzyme velocity?
A.)The substrate concentration must be in excess of the enzyme concentration
B.) The substrate and enzyme concentrations must be equal.
C) The enzyme and substrate reaction must be reversible.
D.) The enzyme concentration must be in excess of the substrate concentration. -
Answers - The substrate concentration must be in excess of the enzyme concentration
What substrate concentration is typically utilized in enzymatic analyses to ensure zero-
order kinetics? - Answers - substrate concentration of 10-100 x Km
A convenient method of assaying enzyme activity is based on measuring the conversion
between the oxidized and reduced forms of nicotinamide adenine dinucleotide
(NAD/NADH). Which form of nicotinamide adenine dinucleotide has a unique
wavelength of absorption is at its maximum? - Answers - reduced, 340nm
When substrate concentration is much greater than KM, the rate of catalysis is almost
equal to - Answers - Vmax
Activity of enzymes in plasma may be determined rather than concentration because -
Answers - The amount of enzyme is too low to measure
, Which CK isoenzyme is elevated in muscle diseases? - Answers - CK-MM
Elevation of serum amylase and lipase is commonly seen in: - Answers - Acute
pancreatitis
What types of inhibition can be reversed? - Answers - Competitive
Mixed
Noncompetitive
One of the enzymes involved in glycolysis, aldolase, requires Zn2+ for catalysis. Under
conditions of zinc deficiency, when the enzyme may lack zinc, it would be referred to as
the - Answers - apoenzyme
Vmax for an enzyme catalyzed reaction: - Answers - is twice the rate observed when
the concentration of substrate is equal to the Km.
A physician orders several laboratory tests on a 55-year-old male patient who is
complaining of generalized (all-over) pain, stiffness, fatigue, and headaches. Based on
the following serum test results, what is the most likely diagnosis: ALP--significantly
increased, GGT-normal - Answers - Bone disease
Which is the most sensitive enzyme for monitoring chronic alcoholic liver disease? -
Answers - GGT
The recommended assay, because of its specificity and sensitivity for the measurement
of the activity of the CK-MB isoenzyme, is the: - Answers - monoclonal sandwich
immunoassay
The usefulness of analyzing lipoprotein-associated phospholipase A2 for the
identification of individuals at risk for future cardiovascular events is because of its: -
Answers - up-regulation in atherosclerotic lessions, particularly complex plague.
Which of the following products are formed from the forward reaction catalyzed by ALT?
- Answers - Pyruvate and glutamate
The major cellular origin of acid phosphatase activity in serum is: - Answers - Prostate
Which of the following methods of measuring enzyme activity utilizes an increase in
absorbance at 340nm as an indicator reaction? - Answers - "Forward" LD reaction
Which of the following enzymes has multiple molecular forms (isoenzymes) whose
clinical significance is used in diagnosis? - Answers - Lactate dehydrogenase, creatine
kinase, and alkaline phosphatase
One extracellular enzyme whose serum activity is measured clinically is: - Answers -
Amylase
ANSWERS
When a reaction is performed in zero-order kinetics: - Answers - The rate of the reaction
is independent of the substrate concentration
Activation energy is: - Answers - Decreased by enzyemes
Examples of cofactors include: - Answers - Zn+2, Mg+2, and Ni+2
Pyridoxal phosphate and coenzyme A
Biotin and thiamine pyrophosphate
Enzyme reaction rates are increased by increasing temperatures until they reach the
point of denaturation at: - Answers - 40-60C
Which of the following is true?
A.) Enzymes force reactions to proceed in only one direction.
B.) Enzymes alter the standard free energy of the reaction
C.) Enzymes alter the equilibrium of the reaction
D.) All of the above
E.) None of the above. - Answers - None of the above
Which of the following is necessary for maximal enzyme velocity?
A.)The substrate concentration must be in excess of the enzyme concentration
B.) The substrate and enzyme concentrations must be equal.
C) The enzyme and substrate reaction must be reversible.
D.) The enzyme concentration must be in excess of the substrate concentration. -
Answers - The substrate concentration must be in excess of the enzyme concentration
What substrate concentration is typically utilized in enzymatic analyses to ensure zero-
order kinetics? - Answers - substrate concentration of 10-100 x Km
A convenient method of assaying enzyme activity is based on measuring the conversion
between the oxidized and reduced forms of nicotinamide adenine dinucleotide
(NAD/NADH). Which form of nicotinamide adenine dinucleotide has a unique
wavelength of absorption is at its maximum? - Answers - reduced, 340nm
When substrate concentration is much greater than KM, the rate of catalysis is almost
equal to - Answers - Vmax
Activity of enzymes in plasma may be determined rather than concentration because -
Answers - The amount of enzyme is too low to measure
, Which CK isoenzyme is elevated in muscle diseases? - Answers - CK-MM
Elevation of serum amylase and lipase is commonly seen in: - Answers - Acute
pancreatitis
What types of inhibition can be reversed? - Answers - Competitive
Mixed
Noncompetitive
One of the enzymes involved in glycolysis, aldolase, requires Zn2+ for catalysis. Under
conditions of zinc deficiency, when the enzyme may lack zinc, it would be referred to as
the - Answers - apoenzyme
Vmax for an enzyme catalyzed reaction: - Answers - is twice the rate observed when
the concentration of substrate is equal to the Km.
A physician orders several laboratory tests on a 55-year-old male patient who is
complaining of generalized (all-over) pain, stiffness, fatigue, and headaches. Based on
the following serum test results, what is the most likely diagnosis: ALP--significantly
increased, GGT-normal - Answers - Bone disease
Which is the most sensitive enzyme for monitoring chronic alcoholic liver disease? -
Answers - GGT
The recommended assay, because of its specificity and sensitivity for the measurement
of the activity of the CK-MB isoenzyme, is the: - Answers - monoclonal sandwich
immunoassay
The usefulness of analyzing lipoprotein-associated phospholipase A2 for the
identification of individuals at risk for future cardiovascular events is because of its: -
Answers - up-regulation in atherosclerotic lessions, particularly complex plague.
Which of the following products are formed from the forward reaction catalyzed by ALT?
- Answers - Pyruvate and glutamate
The major cellular origin of acid phosphatase activity in serum is: - Answers - Prostate
Which of the following methods of measuring enzyme activity utilizes an increase in
absorbance at 340nm as an indicator reaction? - Answers - "Forward" LD reaction
Which of the following enzymes has multiple molecular forms (isoenzymes) whose
clinical significance is used in diagnosis? - Answers - Lactate dehydrogenase, creatine
kinase, and alkaline phosphatase
One extracellular enzyme whose serum activity is measured clinically is: - Answers -
Amylase
