Unit 4 Quesitons Flashcards
All of the enzymes of gluconeogenesis may be found in the cytosol EXCEPT __________ which is only found in the mitochondria.
a) PEP carboxykinase
b) pyruvate carboxylase
c) fructose-1,6,-bisphosphatase
d) glucose-6-phosphatase
e) all are only in cytosol
b) pyruvate carboxylase
In terms of nucleoside triphosphate molecules, what is the main role of the extra cost of gluconeogenesis compared to glycolysis?
a) Nucleoside triphosphate molecules are used for nucleic acid metabolism.
b) Additional nucleoside triphosphates are needed to turn an energetically unfavorable process into a favorable one.
c) Energy is used for lipid breakdown.
d) Nucleoside triphosphates provide more energy for active muscle activity.
b) Additional nucleoside triphosphates are needed to turn an energetically unfavorable process into a favorable one.
The major tissues carrying out gluconeogenesis are the ____ and ____.
liver and kidneys
Predict how this mutation would affect the rate of glycolysis in the liver: Loss of the allosteric site for ATP in phosphofructokinase
a) Glycolysis rate increase
b) Glycolysis rate decrease
a) Glycolysis rate increase
What would be the effect on an orgnaism’s ability to use glucose as an energy source if a mutation inactivated glucose 6 phosphatase in the liver?
The blood glucose concentration would fall, resulting in energy deprivation for glucose dependent tisues
Where is site of glycolysis?
cytosol
What are the key regulatory enzymes of gluconeogenesis?
Glucose 6 phosphatase
Fructose 1,6 biphosphatotase
Pyruvate carboxylase and PEP carboxykinase
High concentrations of fructose 2,6 biphosphate stimulates _____ and inhibits _______
Glycolysis, Gluconeogenesis
Where does pyruvate dehydrogenase complex occur?
Mitochondria Matrix
Order the coenzymes according to their involvement in the pyruvate dehydrogenase complex.
A. NAD+
B. CoA-SH
C. TPP
D. lipoamide
E. [FAD]
C, D, B, E, A,
The three major regulatory enzymes in glycolytic pathway are:
hexokinase, phosphofructokinase, and pyruvate kinase
Glyceraldehyde 3 phosphate is converted to 1,3 biphosphoglycerate by the enzyme glyceraldehyde 3 phosphate dehydrogenase. This reaction reduces which electron carrier?
a. NADP+
b. NADPH
c. NAD+
d. NADH
c. NAD+
What product of conntracting muscle tissue is used by the liver as the starting material for gluconeogenesis?
a. lactate
b. pyruvate
c. glycerol
d. oxaloacetate
a. lactate
How many high energy phosphate bonds are consumed during the process of gluconeogenesis using pyruvate as a starting material?
a. 4
b. 2
c. 6
d. 3
c. 6
These conditions are applied to glycolytic or gluconeogenic pathway?
Increase in AMP
Increase in fructose 2,6 biphosphate
Increase in insulin
Fed
Glycolytic
These conditions are applied to glycolytic or gluconeogenic pathway?
Increase in ATP
Increate in citrate
Increase in acetyl CoA
Increase in glucagon
Fasting
gluconeogenic
Activate glycolysis or activate gluconeogenesis: Increased levels of fructose 2,6 biphosphate
Activate glycolysis
Activate glycolysis or activate gluconeogenesis:
Inhibition of PFK2
Activate gluconeogenesis
Activate glycolysis or activate gluconeogenesis: Increased levels of cAMP
Activate gluconeogenesis
Activate glycolysis or activate gluconeogenesis: activation of PFK2
Activate glycolysis
Activate glycolysis or activate gluconeogenesis: increased glucagon levels
Activate gluconeogenesis
identify the enzymes in order of the three bypass steps in gluconeogenesis
pyruvate carboxylase, PEP carboxykinase, fructose 1,6 biphosphatase, glucose 6 phosphatase
Which compound is not a necessary coenzyme for the function of the pyruvate dehydrogenase complex?
a. FAD
b. NAD+
c. ubiquinone
d. lipoic acid
c. ubiquinone
Which compound is not a product of the reaction catalyzed by the pyruvate dehydrogenase complex?
a. NADH
b. pyruvate
c. acetyl CoA
d. CO2
b. pyruvate
For a given pair of reduced and oxidized molecules (X- and X), a negative reducing potential suggests that
a. X has a higher affinity for e- than H2 does
b. X has a lower affinity for e- than H2 does
c. X- has a higher affinity for e- than X does
d. X- has a lower affinity for e- than X does
b. X has a lower affinity for e- than H2 does
Which of the following describes the direction of proton movement relative to electron transfer and phosphorylation?
A. Electron transfer pumps protons into the matrix. As the protons leave the matrix through the ATP synthase, ATP is produced in the matrix.
B. Electron transfer pumps protons into the matrix. As the protons renter through the ATP synthase, ATP is produced in the intermembrane space
C. Electron transfer pumps protons into the matrix. As the protons reenter through the ATP synthase, ATP is produced in the matrix.
D. Electron transfer pumps protons into the matrix. As the protons leave the matrix through the ATP synthase, ATP is produced on the opposite side of the membrane.
C. Electron transfer pumps protons into the matrix. As the protons reenter through the ATP synthase, ATP is produced in the matrix.
What is the source of electrons transferred by succinate Q reductase (complex II)?
a. NAD+ from the conversion of pyruvate to lactate
b. NADH from the citric acid cycle and glycolysis
c. FADH2 from the citric acid ccyle
d. FAD from pyruvate dehydrogenase
c. FADH2 from the citric acid ccyle
Which electron carrier is NOT mobile or diffusible in the mitochondrial electron transport chain?
a. FAD
b. cytochrome Q
c. ubiquinone
d. cytochrome c
a. FAD
The path taken by electrons from NADH generated during the citric acid cycle to water will NT pass throguh:
a. FAD
b. O2
c. cytochrome Q
d. cytochrome c
a. FAD
The process of glycolysis occurs in the cytoplasm. The electrons from the NADH generated during glycolysis:
A. cannot be used by the mitochondrial electron transport chain because NADH cannot enter the mitochondria.
B. enter the mitochondrial electron chain directly because NADH freely enters the mitochondria.
C. may enter the electron transport chain either at the level of NADH or FADH2, depending on the shuttle system used to transport them into the mitochondria.
C. may enter the electron transport chain either at the level of NADH or FADH2, depending on the shuttle system used to transport them into the mitochondria.
Where can oxidative phosphorylation take place in living organisms? Select all that apply.
a. plasma membrane
b. mitochondrial matrix
c. cristae
d. cytoplasm
e. inner membrane of mitochondrion
a. plasma membrane
c. cristae
e. inner membrane of mitochondrion
How much ATP is yielded from complete oxidation of one molecule of glucose in muscle?
30 ATP
How much ATP is yielded from complete oxidation of one molecule of glucose in liver, heart, kidney?
32 ATP
