©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
BCH4024 Exam 3 Questions And Answers
|Latest 2025 | Guaranteed Pass
What is the structure of a triglyceride? - Answer✔glycerol backbone with three fatty acid chains
What are the main tissues using FA as an energy source? - Answer✔liver, heart, resting skeletal
muscle
Which has a high energy of oxidation: lipids or carbohydrates? (meaning more effective) -
Answer✔lipids
What is the difference in the time of storage between glycogen and lipids? - Answer✔glycogen
stores enough for one day
where
lipids store enough for one month
What is the preferred energy storage form in animals? - Answer✔Triacylglycerides
Lipid catabolism overview:
(1) After ingestion, what is needed to break down dietary fats?
(2) After being broken down, where are dietary fats absorbed? What does this produce?
(3) What happens to the broken down products (hint: what are they resynthesized to and
where)... (where are they then transported to and by what)
1|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
(4) Once at the target tissue, what is broken down? what is it broken down to? and by what? in
what?
(5) What is then oxidized? and why?
(6) Where are the FA stored? and as what? - Answer✔(1) Bile salts and pancreatic lipase
(2) in the small intestine (produces fatty acids and glycerol)
(3) the are resynthesized to lipids in the intestinal cells; transported to different tissues by
lipoproteins
(4) lipids; glycerol and fatty acids; by lipoprotein lipase; in the capillaries
(5) Fatty acids; for fuel (which then go through the 3 stages of oxidation) or reesterfied for
storage (as triglycerides)
(6)adipocytes; as lipid droplets coated with perilipins
What hormones signal the need for energy? - Answer✔Glucagon and Epinephrine
Which 2 things must be phosphorylated for fatty acid breakdown (lipid catabolism specifically
retrieving the stores)? - Answer✔Perilipin & Hormone sensitive lipase (HSL)
*good time to look at lipid catabolism road map*
Where is the majority of the available energy stored in triacylglycerides? Where is the other
available energy? - Answer✔The long-chain fatty acid (95%) ; glycerol metabolism (enters
glycolysis and oxidized to D-gylceraldehyde 3-phosphate) (5%)
Free fatty acids must first be activated to be transported. (1)What is added to activate them?
(2)What does it require? (3)What is the enzyme that catalyzes the reaction? -
Answer✔(1)Acetyl-CoA
(2)Requires ATP
(3)Acetyl-CoA synthetase (to make FA acetyl CoA which is the active form of the FA)
Once a FA is activated and ready for transport it can be transported to which two areas? What
does each area mean? - Answer✔(1) Cytosol - synthesis membrane lipids
2|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
(2) Mitochondria - oxidized to make ATP
Explain the mechanism of converting free fatty acids into fatty acetyl-CoAs (activated form of
fatty acid). - Answer✔(1)The carboxylate ion is adenylated (add AMP group on) by ATP to form
a (product 1) fatty acetyl-adenylate and (product 2) phosphate. The phosphate is immediately
hydrolyzed into two molecules of phosphate.
(2) The thiol group of coenzyme A attacks the fatty acetyl-adenylate, removing AMP and
forming fatty acetyl CoA.
What shuttle is used to carry fatty acids with > 14 carbons across the mitochondrial membrane?
- Answer✔Carnitine
How is the fatty acetyl CoA carried across the membrane? - Answer✔the CoA group is removed
and replaced with Carnitine to be carried across the membrane, once it is carried across the
membrane Carnitine is removed and replaced with CoA group.
What are the (3) stages of fatty acid oxidation? - Answer✔(1) Oxidation of long-chain fatty acid
to acetyl-CoA
(2) Acetyl-CoA oxidized to CO2 by TCA cycle
(3) Electrons from stage 1 and stage 2 oxidations enter the ETC (in which WATER is generated in
the reduction of O2)
For stage 1 in fatty acid oxidation, what are the 4 enzyme-catalyzed reactions in β-oxidation of
saturated fatty acids? - Answer✔Start with 16 chain carbon (palmitate):
(1) cis double bond goes to trans double bond through oxidation and FADH2 is released, the
electrons are transferred to FAD
(2) alkane hydration ( addition of water)
(3) dehydrogenation (where through an oxidation electrons are transferred to NAD)
(4) alpha-beta bond cleavage and release of acetyl CoA [but acetyl CoA is not a final product of
this because it is only produced in stage 1 and then goes into the TCA)
Ends with 14 chain carbon.
3|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
How do you determine how many rounds you will need? - Answer✔( [carbons started with] /
[2] ) - 1
What is the overall production of ATP for Palmitoyl-CoA?
*note palmitate is a 16 carbon chain* - Answer✔108 ATP
What happens if your FA is unsaturated (including both monounsaturated and
polyunsaturated)... what must happen for oxidation? - Answer✔(1) Monounsaturated FA must
be isomerised from cis to trans and then Enoyl-CoA can then react with the trans form for
oxidation
(2) Polyunsaturated FA additionally require 2,4-dienoyl-CoA reductase to achieve the correct
configuration for oxidation
What happens if you FA is odd-chained... what must happen for oxidation? - Answer✔odd-
chained FA are oxidized to 3 carbon-CoA which is metabolized by biotin and Vitamin B12 to
succinyl-CoA (which then enters the TCA)
What happens to excess dietary carbohydrates? - Answer✔they are converted to triagylcerides
for storage
Glycerol oxidation allows for what? - Answer✔for glycerol to enter the glycolysis pathway
What happens to cell with defective perilipin genes? - Answer✔there will be almost no repose
to increased levels of cAMP... because if perilipin is not phosphorylated then it cannot produce
cAMP
What enzyme catalyzes the conversion of glycerol to L-glycerol 3-phosphate? -
Answer✔glycerol kinase
4|Page
BCH4024 Exam 3 Questions And Answers
|Latest 2025 | Guaranteed Pass
What is the structure of a triglyceride? - Answer✔glycerol backbone with three fatty acid chains
What are the main tissues using FA as an energy source? - Answer✔liver, heart, resting skeletal
muscle
Which has a high energy of oxidation: lipids or carbohydrates? (meaning more effective) -
Answer✔lipids
What is the difference in the time of storage between glycogen and lipids? - Answer✔glycogen
stores enough for one day
where
lipids store enough for one month
What is the preferred energy storage form in animals? - Answer✔Triacylglycerides
Lipid catabolism overview:
(1) After ingestion, what is needed to break down dietary fats?
(2) After being broken down, where are dietary fats absorbed? What does this produce?
(3) What happens to the broken down products (hint: what are they resynthesized to and
where)... (where are they then transported to and by what)
1|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
(4) Once at the target tissue, what is broken down? what is it broken down to? and by what? in
what?
(5) What is then oxidized? and why?
(6) Where are the FA stored? and as what? - Answer✔(1) Bile salts and pancreatic lipase
(2) in the small intestine (produces fatty acids and glycerol)
(3) the are resynthesized to lipids in the intestinal cells; transported to different tissues by
lipoproteins
(4) lipids; glycerol and fatty acids; by lipoprotein lipase; in the capillaries
(5) Fatty acids; for fuel (which then go through the 3 stages of oxidation) or reesterfied for
storage (as triglycerides)
(6)adipocytes; as lipid droplets coated with perilipins
What hormones signal the need for energy? - Answer✔Glucagon and Epinephrine
Which 2 things must be phosphorylated for fatty acid breakdown (lipid catabolism specifically
retrieving the stores)? - Answer✔Perilipin & Hormone sensitive lipase (HSL)
*good time to look at lipid catabolism road map*
Where is the majority of the available energy stored in triacylglycerides? Where is the other
available energy? - Answer✔The long-chain fatty acid (95%) ; glycerol metabolism (enters
glycolysis and oxidized to D-gylceraldehyde 3-phosphate) (5%)
Free fatty acids must first be activated to be transported. (1)What is added to activate them?
(2)What does it require? (3)What is the enzyme that catalyzes the reaction? -
Answer✔(1)Acetyl-CoA
(2)Requires ATP
(3)Acetyl-CoA synthetase (to make FA acetyl CoA which is the active form of the FA)
Once a FA is activated and ready for transport it can be transported to which two areas? What
does each area mean? - Answer✔(1) Cytosol - synthesis membrane lipids
2|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
(2) Mitochondria - oxidized to make ATP
Explain the mechanism of converting free fatty acids into fatty acetyl-CoAs (activated form of
fatty acid). - Answer✔(1)The carboxylate ion is adenylated (add AMP group on) by ATP to form
a (product 1) fatty acetyl-adenylate and (product 2) phosphate. The phosphate is immediately
hydrolyzed into two molecules of phosphate.
(2) The thiol group of coenzyme A attacks the fatty acetyl-adenylate, removing AMP and
forming fatty acetyl CoA.
What shuttle is used to carry fatty acids with > 14 carbons across the mitochondrial membrane?
- Answer✔Carnitine
How is the fatty acetyl CoA carried across the membrane? - Answer✔the CoA group is removed
and replaced with Carnitine to be carried across the membrane, once it is carried across the
membrane Carnitine is removed and replaced with CoA group.
What are the (3) stages of fatty acid oxidation? - Answer✔(1) Oxidation of long-chain fatty acid
to acetyl-CoA
(2) Acetyl-CoA oxidized to CO2 by TCA cycle
(3) Electrons from stage 1 and stage 2 oxidations enter the ETC (in which WATER is generated in
the reduction of O2)
For stage 1 in fatty acid oxidation, what are the 4 enzyme-catalyzed reactions in β-oxidation of
saturated fatty acids? - Answer✔Start with 16 chain carbon (palmitate):
(1) cis double bond goes to trans double bond through oxidation and FADH2 is released, the
electrons are transferred to FAD
(2) alkane hydration ( addition of water)
(3) dehydrogenation (where through an oxidation electrons are transferred to NAD)
(4) alpha-beta bond cleavage and release of acetyl CoA [but acetyl CoA is not a final product of
this because it is only produced in stage 1 and then goes into the TCA)
Ends with 14 chain carbon.
3|Page
, ©FYNDLAY 2025 ALL RIGHTS RESERVED 11:49 AM A+
How do you determine how many rounds you will need? - Answer✔( [carbons started with] /
[2] ) - 1
What is the overall production of ATP for Palmitoyl-CoA?
*note palmitate is a 16 carbon chain* - Answer✔108 ATP
What happens if your FA is unsaturated (including both monounsaturated and
polyunsaturated)... what must happen for oxidation? - Answer✔(1) Monounsaturated FA must
be isomerised from cis to trans and then Enoyl-CoA can then react with the trans form for
oxidation
(2) Polyunsaturated FA additionally require 2,4-dienoyl-CoA reductase to achieve the correct
configuration for oxidation
What happens if you FA is odd-chained... what must happen for oxidation? - Answer✔odd-
chained FA are oxidized to 3 carbon-CoA which is metabolized by biotin and Vitamin B12 to
succinyl-CoA (which then enters the TCA)
What happens to excess dietary carbohydrates? - Answer✔they are converted to triagylcerides
for storage
Glycerol oxidation allows for what? - Answer✔for glycerol to enter the glycolysis pathway
What happens to cell with defective perilipin genes? - Answer✔there will be almost no repose
to increased levels of cAMP... because if perilipin is not phosphorylated then it cannot produce
cAMP
What enzyme catalyzes the conversion of glycerol to L-glycerol 3-phosphate? -
Answer✔glycerol kinase
4|Page
