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WorksheetsExam 2 - Corso - Urea Cycle, AA Metabolism, & Enzymes
Total questions: 51
Worksheet time: 4hrs 15mins
A 2 year old male has elevated ammonia. A physician consults with you about treatment of the patient in the case. Which of the following drugs or drug classes would be the most appropriate for treatment?
Lipase inhibitors
Lipostatin
Phenylbutyrate
Sulfonylureas
Which two AA carry most of the waste nitrogen from non-heptic tissue into the liver?
G
A
D
Q
If a young child has a genetic deficiency that prevents the synthesis of arginine, what symptom is most likely
acidosis
ammonia toxicity
kidney stones
A 2 year old male has been suffering form vomiting, lethargy, spasticity and seizures. Blood tests indicate elevated ammonia. Which of the following genetic defects would most likely cause these types of symptoms
Carboxxypeptidase
Ornithine transcarbamylase
Phenylalanine hydroylase
Succinate dehydrogenase
Which of the following amino acids are non-essential and can be made from other amino acids or common metabolites?
A
E
D
G
S
Which of the following amino acids are the only two that are exclusively ketogenic?
K
T
L
E
You are doing a rotation in the neonatal ward and an unusual case is presented. The child has diapers that smell like maple syrup. The most likely cause of this is:
The inability to absorb B12 in the intestine
The inability to decarboxylase branched chain alpha keto acids
The inability to do transamination reactions of amino acids
The synthesis of urea in the kidneys
A patient has PKU, which of the following symptoms would you expect? (select all that apply)
elevated blood phenylalanine
elevated phenylketones in urine
urine that smells musty
impaired mental status
Enzymes have what effect on biochemical reactions?
decrease the overall delta G of a reaction
increase the delta S
increase the rate of equilibrium that is achieved
increase the rate of product formation
The transition state is
the shape of the product
the shape the substrate molecule midway in its transformation to product
the shape of the substrate before reaction begins
the shape of the enzyme
Where on the enzyme does the catalyzed reaction take place
Active Site
Allosteric Site
BPG Binding Domain
What are common features found at the active site? (select all that apply)
metal ions
nucleic acids
titratable amino acids
vitamins
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
apoenzyme
coenzyme
haloenzyme
substrate
What type of enzyme cuts a molecule apart
lyase
hydrolase
ligase
oxidoreductase
What type of enzyme works with NAD+ or FAD?
lyase
hydrolase
ligase
oxidoreductase
What type of enzyme causes water to cleave off a group
isomerase
hydrolase
ligase
transferase
What type of enzyme joins groups together
isomerase
hydrolase
ligase
transferase
What type of enzyme uses SAM
isomerase
hydrolase
ligase
transferase
What type of enzyme rearranges the atoms of a molecule
isomerase
hydrolase
ligase
transferase
Enzyme catalysis increases reaction rates by
preventing product from going back to substrate
holding reactants near each other
Which one of the following is not among the six internationally accepted classes of enzymes?
hydrolase
ligase
oxidoreducatse
polymerase
Enzymes are potent catalysts because they
are consumed in the reactions they catalyze
increase equilibrium constants for the reactions they catalyze
drive reactions to completion while other catalysts drive reactions to equilibrium
lower the activation energy for the reactions they catalyze
What is the definition of Vmax
turnover number - a constant for any enzyme
concentration of substrate that brings about 1/2Vmax
maximal rate of an enzyme catalyzed reaction
initial rate of reaction
What is the definition of Km
turnover number - a constant for any enzyme
concentration of substrate that brings about 1/2Vmax
maximal rate of an enzyme catalyzed reaction
initial rate of reaction
What is the definition of Vo
turnover number - a constant for any enzyme
concentration of substrate that brings about 1/2Vmax
maximal rate of an enzyme catalyzed reaction
initial rate of reaction
What is the definition of kcat
turnover number - a constant for any enzyme
concentration of substrate that brings about 1/2Vmax
maximal rate of an enzyme catalyzed reaction
initial rate of reaction
1.5 min
6 min
13.5 min
27 min
What is the Vmax?
325 micromol/min
500 micromol/min
650 micromol/min
1000 micromol/min
What is the 1/2 Vmax?
325 micromol/min
500 micromol/min
650 micromol/min
1000 micromol/min
What is the Km for this data?
1 mM
2 mM
4 mM
6 mM
What is the Vmax?
0.4 mM/min
0.45 mM/min
0.5 mM/min
0.55 mM/min
What is the y-intercept
-0.013
0.005
0.364
2
Aspirin acetylating an enzyme is an example of
suicide inhibition
enzyme regulation (either activation or suppression)
ATP phosphorylating an enzyme is an example of
suicide inhibition
enzyme regulation (either activation or suppression)
What is an example of feedback inhibition
multimeric enzyme that binds more than one substrate at a time that has lower than expected activity at low substrate concentration
ATP phosphorylating glycogen synthase
affect of ATP on the citric acid cycle
Aspirin acetylating the cyclooxygenase enzyme
hexokinase has a higher affinity for glucose than fructose
What is an example of cooperativity
multimeric enzyme that binds more than one substrate at a time that has lower than expected activity at low substrate concentration
ATP phosphorylating glycogen synthase
affect of ATP on the citric acid cycle
Aspirin acetylating the cyclooxygenase enzyme
hexokinase has a higher affinity for glucose than fructose
What is an example of enzyme regulation
multimeric enzyme that binds more than one substrate at a time that has lower than expected activity at low substrate concentration
ATP phosphorylating glycogen synthase
affect of ATP on the citric acid cycle
Aspirin acetylating the cyclooxygenase enzyme
hexokinase has a higher affinity for glucose than fructose
What is an example of suicide inhibition
multimeric enzyme that binds more than one substrate at a time that has lower than expected activity at low substrate concentration
ATP phosphorylating glycogen synthase
affect of ATP on the citric acid cycle
Aspirin acetylating the cyclooxygenase enzyme
hexokinase has a higher affinity for glucose than fructose
What is an example of structure activity relationship
multimeric enzyme that binds more than one substrate at a time that has lower than expected activity at low substrate concentration
ATP phosphorylating glycogen synthase
affect of ATP on the citric acid cycle
Aspirin acetylating the cyclooxygenase enzyme
hexokinase has a higher affinity for glucose than fructose
For competitive inhibition, the inhibitor binds to the
active site
allosteric site at any time
allosteric site, but only after the substrate has bound the active site
For competitive inhibition, which of the following take place? (select all that apply)
Vmax stays the same
Vmax decreases
Km increases
Km stays the same
the double reciprocal plot crosses the y-intercept at the same place as the uninhibited
For uncompetitive inhibition, the inhibitor binds to the
active site
allosteric site at any time
allosteric site, but only after the substrate has bound the active site
For uncompetitive inhibition, which of the following take place? (select all that apply)
Vmax stays the same
Vmax decreases
Km decreases
Km stays the same
the double reciprocal plot is parallel to the uninhibited plot
For mixed inhibition, which of the following take place? (select all that apply)
Vmax stays the same
Vmax decreases
Km could decrease
Km could increase
the double reciprocal plot is parallel to the uninhibited plot
For non-competitive inhibition, the inhibitor binds to the
active site
allosteric site at any time
allosteric site, but only after the substrate has bound the active site
For non-competitive inhibition, which of the following take place? (select all that apply)
Vmax stays the same
Vmax decreases
Km stays the same
Km could increase
the double reciprocal plot crosses the x-intercept at the same place as the uninhibited
Which of the following describes mixed inhibition
Vmax goes down, Km could go down or could go up
Vmax goes down, Km goes down
Vmax stays the same, Km goes down
Vmax goes down, Km stays the same
Which of the following describes non-competitive inhibition
Vmax goes down, Km could go down or could go up
Vmax goes down, Km goes down
Vmax stays the same, Km goes down
Vmax goes down, Km stays the same
Which of the following describes un-competitive inhibition
Vmax goes down, Km could go down or could go up
Vmax goes down, Km goes down
Vmax stays the same, Km goes down
Vmax goes down, Km stays the same
Which of the following describes competitive inhibition
Vmax goes down, Km could go down or could go up
Vmax goes down, Km goes down
Vmax stays the same, Km goes down
Vmax goes down, Km stays the same
In competitive inhibition, an inhibitor
binds at several different sites on an enzyme
binds covalently to the enzyme
binds only to the ES complex
binds reversibly at the active site
lowers the characteristic Vmax of the enzyme
