BCH 367 UPDATED FINAL EXAM 3 QUESTIONS
AND CORRECT ANSWERS
What is the main purpose of gluconeogenesis? - CORRECT ANSWERS Pyruvate -> Glucose
Where does gluconeogenesis occiur? - CORRECT ANSWERS Liver
When does gluconeogenesis occur? - CORRECT ANSWERS During starvation
What is the main purpose of the Cori Cycle? - CORRECT ANSWERS Lactate to Pyruvate,
then gluconeogenesis
Is gluconeogenesis the reverse of glycolysis? - CORRECT ANSWERS no, has some shared
pathways but the three irreversible steps in glycolysis must be bypassed in gluconeogenesis
How does pyruvate exit the mitochondria during gluconeogenesis? - CORRECT
ANSWERS It must become oxaloacetate, then malate to pass through the membrane and
return back to oxaloacetate
What are the enzymes that replace the irreversible glycolysis steps during gluconeogenesis?
Where does the process occur? - CORRECT ANSWERS 1. Hexokinase -> Glucose 6-
phosphatase (in the ER)
3. PFK -> Fructose 1,6-biphosphotase (in the cytoplasm)
10. Pyruvate Kinase -> Pyruvate carboxylase (in the mitochondria) and PEP carboxylkinase (in
the cytoplasm)
What occurs when blood glucose is low? - CORRECT ANSWERS Glucagon is secreted
, What occurs when blood glucose is high? - CORRECT ANSWERS There is low glucagon
What is glucagon? - CORRECT ANSWERS Hormone that stimulates glucose production
Requirements for gluconeogensis to occur? - CORRECT ANSWERS Six high transfer-
potential phosphoryl groups (i.e. ATP or GTP)
PDH enzymes - CORRECT ANSWERS E1: Decarboxylation
E1/E2: Oxidation
E2: Transfer to CoA
E3: Regenerates lipoamide, which is involved in second step(E1/E2)
Important characteristics of Thiamine pyrophosphate (TPP) - CORRECT ANSWERS Has a
nitrogen to stabilize the carbanion form which makes it a good nucleophile to attack pyruvate
What complex makes Acetyl CoA from pyruvate? - CORRECT ANSWERS Pyruvate
dehydrogenase complex (PDH)
Under what conditions does pyruvate enter the mitochondria? - CORRECT
ANSWERS Aerobic
What is the Warburg effect? - CORRECT ANSWERS Even in the presence of oxygen, cancer
cell preferentially undergo Glycolysis/Lactic acid fermentation over more energy efficient
mitochondrial oxidative phosphorylation pathways.
Non-covalent Regulation of PDH: What inhibits the PDH complex? - CORRECT
ANSWERS Allosterically- Acetyl CoA and NADH
AND CORRECT ANSWERS
What is the main purpose of gluconeogenesis? - CORRECT ANSWERS Pyruvate -> Glucose
Where does gluconeogenesis occiur? - CORRECT ANSWERS Liver
When does gluconeogenesis occur? - CORRECT ANSWERS During starvation
What is the main purpose of the Cori Cycle? - CORRECT ANSWERS Lactate to Pyruvate,
then gluconeogenesis
Is gluconeogenesis the reverse of glycolysis? - CORRECT ANSWERS no, has some shared
pathways but the three irreversible steps in glycolysis must be bypassed in gluconeogenesis
How does pyruvate exit the mitochondria during gluconeogenesis? - CORRECT
ANSWERS It must become oxaloacetate, then malate to pass through the membrane and
return back to oxaloacetate
What are the enzymes that replace the irreversible glycolysis steps during gluconeogenesis?
Where does the process occur? - CORRECT ANSWERS 1. Hexokinase -> Glucose 6-
phosphatase (in the ER)
3. PFK -> Fructose 1,6-biphosphotase (in the cytoplasm)
10. Pyruvate Kinase -> Pyruvate carboxylase (in the mitochondria) and PEP carboxylkinase (in
the cytoplasm)
What occurs when blood glucose is low? - CORRECT ANSWERS Glucagon is secreted
, What occurs when blood glucose is high? - CORRECT ANSWERS There is low glucagon
What is glucagon? - CORRECT ANSWERS Hormone that stimulates glucose production
Requirements for gluconeogensis to occur? - CORRECT ANSWERS Six high transfer-
potential phosphoryl groups (i.e. ATP or GTP)
PDH enzymes - CORRECT ANSWERS E1: Decarboxylation
E1/E2: Oxidation
E2: Transfer to CoA
E3: Regenerates lipoamide, which is involved in second step(E1/E2)
Important characteristics of Thiamine pyrophosphate (TPP) - CORRECT ANSWERS Has a
nitrogen to stabilize the carbanion form which makes it a good nucleophile to attack pyruvate
What complex makes Acetyl CoA from pyruvate? - CORRECT ANSWERS Pyruvate
dehydrogenase complex (PDH)
Under what conditions does pyruvate enter the mitochondria? - CORRECT
ANSWERS Aerobic
What is the Warburg effect? - CORRECT ANSWERS Even in the presence of oxygen, cancer
cell preferentially undergo Glycolysis/Lactic acid fermentation over more energy efficient
mitochondrial oxidative phosphorylation pathways.
Non-covalent Regulation of PDH: What inhibits the PDH complex? - CORRECT
ANSWERS Allosterically- Acetyl CoA and NADH
