Concept explainers
(a)
Interpretation: To characterize carbamoyl phosphate in terms of nitrogen content
Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. Urea cycle can be explained in terms of the nitrogen content of all the compounds participating in the urea cycle as follows:
(b)
Interpretation: To characterize ammonium ion in terms of nitrogen content
Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine.
Urea cycle can be explained in terms of the nitrogen content of all the compounds participating in the urea cycle as follows:
(c)
Interpretation: To characterize fumarate in terms of nitrogen content
Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. Urea cycle can be explained in terms of the nitrogen content of all the compounds participating in the urea cycle as follows:
(d)
Interpretation: To characterize urea in terms of nitrogen content
Concept introduction: Urea cycle is a cyclic biochemical pathway that involves the production of urea using ammonium ions and aspartate molecules as nitrogen sources. It converts toxic ammonium ion to urea which is then excreted from the body in urine. Urea cycle can be explained in terms of the nitrogen content of all the compounds participating in the urea cycle as follows:
Want to see the full answer?
Check out a sample textbook solutionChapter 26 Solutions
EBK GENERAL, ORGANIC, AND BIOLOGICAL CH
- Which of the following is a substrate in the urea cycle? a. fumarate b. glutamate c. aspartate d. α-ketoglutaratearrow_forwardIf aspartate is labeled with deuterium D (= H-2 = 12H), answer questions a-c to determine where the label will end up in oxaloacetate after the involvement of aspartate in the urea cycle. Where does the label end up in arginosuccinate? Where is the label in fumarate? Where is the label in oxaloacetate?arrow_forwardCarbamoyl-phosphate synthase I is a mitochondrial enzyme which plays an important role in the urea cycle. It represents the committed step in the urea cycle. (i) Explain the reaction of carbamoyl-phosphate synthase I. (ii) Explain the regulation of urea cycle by N-acetylglutamate.arrow_forward
- Identify urea in the Urea cycle below and show/explain where the two Nitrogen atoms of urea originate from. 3 2 ATP + HCO3 + NH3 4 CPS-1 2 ADP, P₁ NH3 CH₂ CH₂ CH₂ HC-NH3 Coo 1 7 H₂N NH₂ H₂N O=UN ARG1 H₂O OPO3²- feeli. NH₂ CH₂ CH₂ OTC CH₂ P₁ HỘ—NH3* ·8-3-4-8 • ASL CH 5 ΝΗ CH₂ CH₂ CH₂ HỘNH3 COO NH₂ 3 3 ASS NH COO ΝΗ CH₂ CH₂ COO- CH₂ CH₂ HỘ NH3* COO 4 ATP PP₁ L-Asp AMParrow_forwardDiscuss the two roles of N-acetylglutamate in the urea cycle. Include relevant chemical structures and reactions. What is the regulatory function of N-acetylglutamate in the urea cycle? What is the other role of N-acetylglutamate in relationship to the urea cycle? Glutamate is the precursor for N-acetylglutamate. How is glutamate involved in the connection between the urea cycle and the CAC?arrow_forwardUsing the model above, illustrate the urea cycle.arrow_forward
- Discuss the toxic effects of the ammonium ion and excess bicarbonate ion. What is the effect of high concentrations of NH4+ in the bloodstream? What are the two reasons NH4+ is so toxic to the brain? Why can the urea cycle also be considered as a bicarbonate ion disposal mechanism? Why is that important?arrow_forward4. The urea cycle was the first metabolic cycle to be discovered, predating the description of the citric acid cycle by 5 years. Hans Krebs along with Kurt Henseleit used their Warburg manometer (pictured) to monitor the use of carbon dioxide and ammonia in the synthesis of urea. In the presence of a slice of liver, urea could be produced, but the reaction require ornithine and citrulline. Since citrulline is not consumed during the course of the enzymatic cycle, but is rather regenerated, Krebs described citrulline as a "catalyst" of the process. H2N ÑH2arrow_forwardConsider the following Statements: (1) Citric acid cycle intermediates are often the products from amino acid carbon skeleton degradation. (2) The net effect of transamination is to collect the amino groups from a variety of amino acids into the amino acids glutamate and aspartate. (3) All of the reactions of the urea cycle occur within mitochondria. how many is truearrow_forward
- If aspartate is labeled with deuterium D (= H-2 = 12H), answer questions a-c to determine where the label will end up in oxaloacetate after the involvement of aspartate in the urea cycle.arrow_forwardb) Explain the urea cycle and summarize the steps of the urea carbamoyl phosphate. cycle starting fromarrow_forwardDefine the following terms: a. thiolytic cleavage b. ketogenesis c. ketone bodies d. α-oxidation e. ACCarrow_forward