1. LEHNINGER PRINCIPLES OF BIOCHEMISTRY
David L. Nelson and Michael M. Cox
LEHNINGER
PRINCIPLES OF BIOCHEMISTRY
Sixth Edition
CHAPTER 14
Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway
© 2013 W. H. Freeman and Company

3. The two phases of glycolysis

22. Breakdown of intracellular glycogen by glycogen phosphorylase

23. Metabolism of fructose for entry into glycolysis

24. Metabolism of galactose for entry into glycolysis
Galactose is phosphorylated at carbon-1 by galactokinase to produce galactose 1-phosphate.
Galactose is a C-4 epimer of glucose. Galactose 1-phosphate is converted to glucose 1-phosphate through a UDP nucleotide derivative and the enzyme UDP-glucose 4-epimerase.

25. Metabolism of mannose for entry into glycolysis

26. Under aerobic conditions NADH transfers its electrons eventually to oxygen, regenerating NAD+.
Under anaerobic conditions pyruvate is reduced to lactate to regenerate NAD+ for glycolysis to continue.

27. Yeast contain the enzyme pyruvate decarboxylase that decarboxylates pyruvate to form acetaldehyde. Acetaldehyde is then reduced to ethanol under anaerobic conditions.

28. The human brain consumes over 120 grams of glucose each day
Gluconeogenesis Glucose is made in the liver and transported to the brain in the blood stream.
The human brain consumes over 120 grams of glucose each day

32. Alternative paths from pyruvate to phosphoenolpyruvate

34. General scheme of the pentose phosphate pathway

35. NADPH in high concentrations feedback inhibits the pentose phosphate pathway