Biochemistry Final Exam: UNE CHEM
1005 With Correct Answers 2025-2026
Update.
Control of Fatty Acid Synthesis vs. Oxidation - Answer When Insulin is HIGH --> fatty acid
synthesis occurs
When Glucagon is HIGH --> lipolysis, fatty acid B-oxidation, ketogenesis occur
**These never happen at the same time!
Lipolysis - Answer Process of releasing free fatty acids from triacylglycerols stored in the
adipose IN THE FASTED STATE
Steps of lipolysis - Answer 1) Hormone Sensitive Lipase: activated by glucagon and
epinephrine
TAGs are hydrolyzed into FFAs and glycerol (inhibited by insulin)
2) Long chain FFAs travel bound to albumin to peripheral tissues to be used as energy source
3) Glycerol travels to liver to be used as gluconeogenesis substrate
4) Acyl-CoA Synthetase: can reconvert FFAs to acyl-CoA to be used for re-esterification in the
adipose (continuous cycle of lipolysis & re-esterification)
Beta Oxidation - Answer Process of generating acetyl-CoA, NADH, and FADH2 from the
oxidation of FFAs taken up by peripheral tissues (mostly liver & skel. muscle tissue).
Happens in mitochondria. Long chain FFAs cannot cross the mito membrane, so a transport
system is in place.
Ketogenesis - Answer Process of generating ketones from excess acteyl-CoA produced from
Beta-Oxidation
Mitochondrial pathway
Ketones can be used as fuel by other tissues but cannot be oxidized by... - Answer The liver.
Skeletal muscle can oxidize ketones.
The brain will oxidize ketones when starving.
, Ketogenesis is regulated by... - Answer 1) Activity of lipolysis
2) Cytosolic levels of malonyl-CoA (which inhibit CPTI)
3) Flux through the TCA depending on NADH levels & concentration of intermediates (especially
OAA)
Ketoacidosis can occur from prolonged ketogenesis, such as... - Answer During starvation
and uncontrolled diabetes
Important connections between Beta-Oxidation and other pathways - Answer 1) It supplies
high levels of ATP in the fasted state
2) ATP is required for both process of glucose synthesis via gluconeogenesis & nitrogen disposal
via the urea cycle
3) deficiencies in beta-oxidation can result in hypoglycemia due to inability to support glucose
synthesis (such as CPTI deficiency, or medium chain acyl-dehydrogenase deficiency)
Fatty Acid Synthesis: Activators & Inhibitors - Answer Activated by insulin
Inhibited by glucagon
Fatty acid synthesis takes place in the... - Answer Cytosol
Fatty acid synthesis: what occurs in the mitochondria? - Answer Substrates need to be
shuttled out of the mitochondria
In the mito:
-Acetyl-CoA and OAA in the mito --> citrate
-Tricarboxylate transporter --> removes excess citrate from the mito
Fatty acid elongation - Answer Requires malonyl-CoA, fatty acyl-CoA and NADPH.
This pathway determines the chain length for fatty acids (medium, long, etc.)
Fatty acid synthesis connection to the PPP - Answer PPP provides glycerol (for TAG synthesis)
and NADPH (for fatty acid synthesis)
Fate of newly synthesized fatty acids - Answer -Fatty acids are NOT stored in the liver
1005 With Correct Answers 2025-2026
Update.
Control of Fatty Acid Synthesis vs. Oxidation - Answer When Insulin is HIGH --> fatty acid
synthesis occurs
When Glucagon is HIGH --> lipolysis, fatty acid B-oxidation, ketogenesis occur
**These never happen at the same time!
Lipolysis - Answer Process of releasing free fatty acids from triacylglycerols stored in the
adipose IN THE FASTED STATE
Steps of lipolysis - Answer 1) Hormone Sensitive Lipase: activated by glucagon and
epinephrine
TAGs are hydrolyzed into FFAs and glycerol (inhibited by insulin)
2) Long chain FFAs travel bound to albumin to peripheral tissues to be used as energy source
3) Glycerol travels to liver to be used as gluconeogenesis substrate
4) Acyl-CoA Synthetase: can reconvert FFAs to acyl-CoA to be used for re-esterification in the
adipose (continuous cycle of lipolysis & re-esterification)
Beta Oxidation - Answer Process of generating acetyl-CoA, NADH, and FADH2 from the
oxidation of FFAs taken up by peripheral tissues (mostly liver & skel. muscle tissue).
Happens in mitochondria. Long chain FFAs cannot cross the mito membrane, so a transport
system is in place.
Ketogenesis - Answer Process of generating ketones from excess acteyl-CoA produced from
Beta-Oxidation
Mitochondrial pathway
Ketones can be used as fuel by other tissues but cannot be oxidized by... - Answer The liver.
Skeletal muscle can oxidize ketones.
The brain will oxidize ketones when starving.
, Ketogenesis is regulated by... - Answer 1) Activity of lipolysis
2) Cytosolic levels of malonyl-CoA (which inhibit CPTI)
3) Flux through the TCA depending on NADH levels & concentration of intermediates (especially
OAA)
Ketoacidosis can occur from prolonged ketogenesis, such as... - Answer During starvation
and uncontrolled diabetes
Important connections between Beta-Oxidation and other pathways - Answer 1) It supplies
high levels of ATP in the fasted state
2) ATP is required for both process of glucose synthesis via gluconeogenesis & nitrogen disposal
via the urea cycle
3) deficiencies in beta-oxidation can result in hypoglycemia due to inability to support glucose
synthesis (such as CPTI deficiency, or medium chain acyl-dehydrogenase deficiency)
Fatty Acid Synthesis: Activators & Inhibitors - Answer Activated by insulin
Inhibited by glucagon
Fatty acid synthesis takes place in the... - Answer Cytosol
Fatty acid synthesis: what occurs in the mitochondria? - Answer Substrates need to be
shuttled out of the mitochondria
In the mito:
-Acetyl-CoA and OAA in the mito --> citrate
-Tricarboxylate transporter --> removes excess citrate from the mito
Fatty acid elongation - Answer Requires malonyl-CoA, fatty acyl-CoA and NADPH.
This pathway determines the chain length for fatty acids (medium, long, etc.)
Fatty acid synthesis connection to the PPP - Answer PPP provides glycerol (for TAG synthesis)
and NADPH (for fatty acid synthesis)
Fate of newly synthesized fatty acids - Answer -Fatty acids are NOT stored in the liver
