Chemistry 451

Lecture #18: High Energy compounds and Redox Reactions

Read: pg. 361-370; optional reading: pg. 371-380

HW: pg. 380 (study exercises; 3,4,5; problems; 2,4)

Optional HW: pg. 380 (problems 5,6,7,10)

Objectives:

  1. The free energy of the "high-energy" compound ATP is made available through cleavage of one or both of its phosphoanhydride bonds. Know what factors stabilize products of hydrolysis.
  2. An exergonic reaction such as ATP or PPI hydrolysis can be coupled to an endergonic reaction to make it more favorable.
  3. Substrate level phosphorylation is the synthesis of ATP from ADP by phosphoryl group transfer from another compound.
  4. The common product of carbohydrate, lipid and protein catabolism, acetyl-CoA, is a "high-energy" thioester.
  5. Know why creatine is said to be a "buffer" of ATP.
  6. The coenzymes NAD+ and FAD are reversibly reduced during the oxidation of metabolites. Know the metabolic role of reduced coenzymes.
  7. Know that NMR is a powerful, non-invasive tool for tracing metabolic pathways and flux through pathways in vivo.

 

NMR:

Sibson NR, Dhankhar A, Mason GF, Rothman DL, Behar KL, Shulman RG. Stoichiometric coupling of brain glucose metabolism and glutamatergic neuronal activity. Proc Natl Acad Sci U S A. 1998 Jan 6;95(1):316-21.

Sibson NR, Dhankhar A, Mason GF, Behar KL, Rothman DL, Shulman RG.In vivo 13C NMR measurements of cerebral glutamine synthesis as evidence for glutamate-glutamine cycling.Proc Natl Acad Sci U S A. 1997 Mar 18;94(6):2699-704.

Creatine:

Greenhaff, P.L Creatine and its application as an ergogenic aid. International Journal of Sport Nutrition (1995) 5:S100-S110.

Greenhaff, PL; Casey, A; Short, AH; Harris, RC; Soderlund, K and Hultman, E. Influence of oral creatine supplementation on muscle torque during repeated bouts of maximal voluntary exercise in man. Clinical Science (1993) 84:565-571.

Walker, JB Creatine: Biosynthesis, regulation and function. Advances in Enzymology and Related Areas of Molecular Biology (1979) 50:177-242.