ANIMAL METABOLISM 



355 



3. Summarize the main factors operating to control the blood sugar level. 



4. Is lactic acid one of the intermediate substances formed on the main pathway 

 of normal carbohydrate metabolism? Under which conditions is it formed in con- 

 siderable amounts? Why is it formed? What becomes of it? 



5. Show by balanced equations the net result of glycolysis, starting with glucose; 

 of the combined operation of the citric acid cycle and the cytochrome system, starting 

 with pj-ruvic acid. 



6. List four phosphorylated and six nonphosphorylated intermediate substances 

 involved in carbohydrate metabolism. 



7. Summarize the evidence as to whether stored fat is motabolically active or 

 inert. 



8. What is meant by "beta" oxidation of fatty acids; by "omega" oxidation? 

 Which is most important in animal tissues? 



9. List eight substances which may be more or less directly produced from acetic 

 acid in animal tissues. 



10. Discuss the relationship between the ability of animal tissues to carry out 

 synthetic reactions and the need for amino acids or proteins in an animal's food. 



11. Which metabolic reactions ser\'e to link together the metabolism of carbo- 

 hydrates and proteins; of carbohydrates and fats? 



12. What is transmethylation? Name the substances now known to serve as 

 methyl group donors, and list several substances produced in the body as a result 

 of methylation. 



13. Name 5 substances produced in the animal body wholly or partially from 

 glycine. 



14. Which amino acids are ketogenic; antiketogenic? 



REFERENCES AND SUGGESTED READINGS 



Baldwin, E.. Dynamic Aspects of Biocheniistnj, 2nd ed., Cambridge University 



Press, Cambridge, 1952. 

 Bloch, K., "The Metabolism of Acetic Acid in Animal Tissues," Physiol. Rev., 27, 



574 (1947). 

 Bloch, K. and Rittenberg, D., "An Estimation of Acetic Acid Formation in the Rat," 



J. Biol. Chem., 159, 45 (1945). 

 Bloor, W. R., Biochemistry of the Fatty Acids, Reinhold Publishing Corporation, 



New York, 1943. 

 Borsook, H., "Protein Turnover and Incorporation of Labeled Amino Acids into 



Tissue Proteins in Vivo and in Vitro," Physiol. Rev., 30, 206 (1950). 

 Breusch, F. L., "The Biochemistry of Fatty Acid Catabolism," Advances in Enzymol- 



ogy, 8,343 (1948). 

 Chaikoff, I. L. and Entenman, C, "Anti-Fatty Liver Factor of the Pancreas," 



Advances in Enzymology, 8, 171 (1948). 

 Cohen, P. P, and Grisolia, S., "The Intermediate Role of Carbamyl-L-Glutamic Acid 



in Citndline Synthesis," J. Biol. Chem., 174, 389 (1948). 

 Duel, H. J. and Morehouse, M. G., "The Interrelation of Carbohydrate and Fat 



Metabolism," Advances in Carbohydrate Chemistry, 2, 119 (1946). 

 du Vigneaud, V., Ressler, C, and Rachele, J. R., "The Biological Synthesis of 'Labile 



Methyl Groups,'" Science, 112, 267 (1950). 

 Gortner, R. A. Jr. and Gortner, W. A., Outlines of Biochemistry, 3rd ed., John Wiley 



and Sons, Inc., New York, 1949, Chapters 19, 20, 26, and 32. 

 Greenberg, D. M. (editor) Amino Acids and Proteins, Charles C. Thomas, Publisher, 



Springfield, 1951, Chapters X, XIII. 



