(a)
Interpretation:
The balanced equation for the oxidation to CO2 and water of myristic acid should be written.
Concept Introduction:
The pathway of ß oxidation of saturated fatty acids involves repetitive four steps. The first three steps are to create a carbonyl group on ß carbon by oxidizing the bond between a and ß carbon. The resulted olefin is subsequently subjected to hydration and oxidation. In the fourth step ß keto ester is cleaved in a reverse Claisen condensation reaction, leaving an acetate unit and a fatty acid chain that lacks two carbons than it had. This shorter fatty acid chain can again participate in another ß oxidation cycle. The acetyl CoA produced is further
Explanation of Solution
Myristic acid is a saturated fatty acid. First myristic acid is converted into a CoA derivative before the ß oxidation.
Then after six circles of ß oxidation myristoyl CoA is converted into 7 acetyl CoA units.
Then the acetyl CoA produced enter into TCA cycle
Above reaction is achieved by GDP phosphorylation. It is equivalent to
NAD+ is recycled in electron transport chain
Above reaction supports the production of
FAD is recycled by
Above reaction supports the production of
AMP produced is phosphorylated to ADP using ATP and PPi is hydrolyzed.
Therefore the overall equation will be
(b)
Interpretation The balanced equation for the oxidation to CO2 and water of stearic acid should be written.
Concept Introduction:
The pathway of ß oxidation of saturated fatty acids involves repetitive four steps. The first three steps are to create a carbonyl group on ß carbon by oxidizing the bond between a and ß carbon. The resulted olefin is subsequently subjected to hydration and oxidation. In the fourth step ß keto ester is cleaved in a reverse Claisen condensation reaction, leaving an acetate unit and a fatty acid chain that lacks two carbons than it had. This shorter fatty acid chain can again participate in another ß oxidation cycle. The acetyl CoA produced is further metabolized in TCA cycle and amino acid biosynthesis.
Explanation of Solution
Stearic acid is a saturated fatty acid. First stearic acid is converted into a CoA derivative before the ß oxidation.
Then after eight circles of ß oxidation stearoyl CoA is converted into 9 acetyl CoA units.
Then the acetyl CoA produced enter into TCA cycle
Above reaction is achieved by GDP phosphorylation. It is equivalent to
NAD+ is recycled in electron transport chain
Above reaction supports the production of
FAD is recycled by
Above reaction supports the production of
AMP produced is phosphorylated to ADP using ATP and PPi is hydrolyzed.
Therefore the overall equation will be
(c)
Interpretation:
The balanced equation for the oxidation to CO2 and water of a-linolenic acid should be written.
Concept Introduction:
Unsaturated fatty acids are also subjected to ß oxidation. But for this two additional enzymes; an isomerase and a reductase are essential to manipulate cis double bonds of fatty acid. As the first steps for monounsaturated fatty acids like oleic acid which is a 18 carbon fatty acid with one double bond at 9,10 position., it normally undergoes the ß oxidation leaving 3 acetyl CoA and the cis-cis-Δ3-dodecenoyl-CoA product. This intermediate is not a substrate for acyl CoA dehydrogenase. This intermediate is then subjected to enoyl-CoA isomerase enzyme activity which rearranges the cis-Δ3 double bond to a trans-Δ2 double bond. This intermediate with trans-Δ2 double bond is preceded via normal ß oxidation.
But for poly unsaturated fatty acids like linoleic acid, ß oxidation occurs through three cycles and the enoyl CoA product is subjected to enoyl-CoA isomerase permitting another round of ß oxidation. The resulting cis-Δ4 enoyl CoA is converted normally to trans-Δ2, cis-Δ4 species by acyl CoA dehydrogenase. This product is not a substrate for enoyl CoA hydratase. In mammals 2,4-dienoyl CoA reductase produces a trans-Δ3 enoyl product which is then converted to the trans-Δ2 CoA by an enoyl CoA isomerase. This product then can normally participate in the ß oxidation.
Explanation of Solution
a linolenic acid is a polyunsaturated C-18 fatty acid with three double bonds at C-9, C-12 and C-15 positions. Eight rounds of ß oxidation will produce 9 molecules of acetyl CoA, without the reduction of FAD into FADH2 in two steps. Therefore two fewer molecules of FADH2 will enter into electron transport chain than in the case of stearic acid and 1 fewer molecule of O2 will be consumed. Therefore amount of ATP is reduced by 3, because
Therefore the overall equation will be
(d)
Interpretation:
The balanced equation for the oxidation to CO2 and water of a-linolenic acid should be written.
Concept Introduction:
Unsaturated fatty acids are also subjected to ß oxidation. But for this two additional enzymes; an isomerase and a reductase are essential to manipulate cis double bonds of fatty acid. As the first steps for monounsaturated fatty acids like oleic acid which is a 18 carbon fatty acid with one double bond at 9,10 position., it normally undergoes the ß oxidation leaving 3 acetyl CoA and the cis-cis-Δ3-dodecenoyl-CoA product. This intermediate is not a substrate for acyl CoA dehydrogenase. This intermediate is then subjected to enoyl-CoA isomerase enzyme activity which rearranges the cis-Δ3 double bond to a trans-Δ2 double bond. This intermediate with trans-Δ2 double bond is preceded via normal ß oxidation.
But for poly unsaturated fatty acids like linoleic acid, ß oxidation occurs through three cycles and the enoyl CoA product is subjected to enoyl-CoA isomerase permitting another round of ß oxidation. The resulting cis-Δ4 enoyl CoA is converted normally to trans-Δ2, cis-Δ4 species by acyl CoA dehydrogenase. This product is not a substrate for enoyl CoA hydratase. In mammals 2,4-dienoyl CoA reductase produces a trans-Δ3 enoyl product which is then converted to the trans-Δ2 CoA by an enoyl CoA isomerase. This product then can normally participate in the ß oxidation.
Explanation of Solution
Arachidonic acid is a polyunsaturated C-20 fatty acid with four double bonds at C-5, C-8, C-11 and C-14 positions. 9 rounds of ß oxidation will produce 10 molecules of acetyl CoA, without the reduction of FAD into FADH2 in two steps. Therefore two fewer molecules of FADH2 will enter into electron transport chain than in the case of stearic acid. Furthermore two NADH molecules will be consumed to resolve two conjugated double bonds.
Therefore the overall equation will be
Want to see more full solutions like this?
Chapter 23 Solutions
Biochemistry
- Determine the yield in water for the complete oxidation of 1 molecule of a triglyceride containing 3, C16 fatty acids. Please do not show the (7-C)-6 formula. Can you please show me where each water molecule comes from that is considered for this calculation (TCA, ETC, B-oxidation and ATP synthase)? Thank you!arrow_forward. Write a balanced equation for the complete oxidation of each of the following, and calculate the respiratory quotient for each substance. (a) Ethanol (b) Acetic acid (c) Stearic acid (d) Oleic acid (e) Linoleic acidarrow_forwardConsider decosanoic acid C12H43CO2H SUB PART TO BE SOLVED How many cycles of beta-oxidation are needed for complete oxidation? How many molecules of ATP are formed from the complete catabolism of this fatty acid? Show the complete computation. How many moles of ATP per gram of fatty acid is formed from the complete catabolism of the given fatty acid? What is the molar mass of the given fatty acid? Solution: Show here the complete computations, [from 1 to 4]arrow_forward
- Calculate the energy yield from complete oxidation of one molecule of tetracosanoic acid (24:0)and nervonic acid (cis-15-tetracosenoic acid) (24:1, w-9)arrow_forwardAscorbic acid: What does it mean to say that ascorbic acid is a strong reducing agent? What is the active form of ascorbic acid in plasma and how is it formed? How can we distinguish the various oxidation states of ascorbic acid? Using chemical symbols or structures, illustrate the reducing activity of ascorbate in forming ascorbyl radical and dehydroascorbic acid Why do we refer to the ascorbate/ascorbyl-radical/dehydroascorbate system as a reversible redox system? Explain the role of ascorbic acid in: Collagen synthesis Iron absorption Regeneration of a-tocopherolarrow_forwardComparing stearate to palmitate, concerning beta oxidation, how many more ATP will be formed from stearate? Comparing stearate to palmitate, concerning complete oxidation, how many more total ATP will be formed from stearate?arrow_forward
- ATP Accounting Upon digestion of starch, isomaltose (an isomer of maltose), one of its degradation products, is further hydrolyzed into its monosaccharide components prior to intestinal absorption and entry into the glycolysis. Calculate the number of ATP molecules produced from the digestion and complete oxidation of 1 molecule of isomaltose considering the glycerol 3-phosphate shuttle. Answer the following items using numerical value only (e.g. 1, not "1 ATP") which will help you arrive at the final answer for this question. a. Total number of glucose molecules entering glycolysis: 1 b. Total number of pyruvate molecules produced at the end of glycolysis: 2 c. Total number of mitochondrial NADH produced after pyruvate is acted upon by the pyruvate dehydrogenase complex: d. Total number of CO2 released right after the pyruvate dehydrogenase complex reaction: e. Total number of acetyl CoA molecules entering the citric acid cycle: f. Total number of net cytosolic ATP molecules produced…arrow_forwardSaccharides: Using the following substrates, estimate the net ATP yield after glycolytic pathway, Kreb’s cycle and electron transport chain. Assume that the estimate for ATP yield per mole of NADH is 3 moles of ATP, while 1 mole of FADH2 is equivalent to 2 moles of ATP, and one mole of GTP is equivalent to one mole of ATP. Show all pertinent solutions and determine: a) ATP used, b) ATP produced, and c) Net ATP. Based on your solutions, rank the substrates based on increasing yield of ATP Two moles of fructose-1,6-biphosphatearrow_forwardSaccharides: Using the following substrates, estimate the net ATP yield after glycolytic pathway, Kreb’s cycle and electron transport chain. Assume that the estimate for ATP yield per mole of NADH is 3 moles of ATP, while 1 mole of FADH2 is equivalent to 2 moles of ATP, and one mole of GTP is equivalent to one mole of ATP. Show all pertinent solutions and determine: a) ATP used, b) ATP produced, and c) Net ATP. Based on your solutions, rank the substrates based on increasing yield of ATP 1. Three moles of glucose-6-phosphate 2. Four moles of pyruvic acidarrow_forward
- Saccharides: Using the following substrates, estimate the net ATP yield after glycolytic pathway, Kreb’s cycle and electron transport chain. Assume that the estimate for ATP yield per mole of NADH is 3 moles of ATP, while 1 mole of FADH2 is equivalent to 2 moles of ATP, and one mole of GTP is equivalent to one mole of ATP. Show all pertinent solutions and determine: a) ATP used, b) ATP produced, and c) Net ATP. Based on your solutions, rank the substrates based on increasing yield of ATP 1. Three moles of glucose-6-phosphatearrow_forwardSaccharides: Using the following substrates, estimate the net ATP yield after glycolytic pathway, Kreb’s cycle and electron transport chain. Assume that the estimate for ATP yield per mole of NADH is 3 moles of ATP, while 1 mole of FADH2 is equivalent to 2 moles of ATP, and one mole of GTP is equivalent to one mole of ATP. Show all pertinent solutions and determine: a) ATP used, b) ATP produced, and c) Net ATP. Based on your solutions, rank the substrates based on increasing yield of ATP Five moles of Acetyl coenzyme Aarrow_forwardCalculate the total number of ATP that can be generated from the ß-oxidation of paulinic acid? ОН 1. How many ATP expended for activating fatty acid to fatty acyl-CoA? How many rounds of beta oxidation? How many FADH2 per round of beta oxidation? Is there any point in the beta oxidation of an unsaturated fatty acid where we skip over FADH, production? How many FADH, total from beta oxidation? How many NADH per round of beta oxidation? How many NADH total from beta oxidation? How many acetyl-CoA are produced through beta oxidation? 6. 2. 3. 4. 5. How many NADH and FADH, are produced per acetyl-CoA in the citric acid cycle? How many NADH total from all acetyl-CoA running through the citric acid cycle? How many FADH, total from all acetyl-CoA running through the citric acid cycle? How many ATP are produced per acetyl-CoA in the citric acid cycle? How many ATP total from all acetyl-CoA running through the citric acid cycle? How many ATP per NADH,? 9. 7. 1. 8. How many ATP per FADH,? 10.…arrow_forward
- BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage Learning