INTER 111: Graduate Biochemistry

Electron transport Oxidative phosphorylation R5P Glucose Pyruvate NADH + H + and ATP Glycogen Disaccharides Acetyl CoA NADH + H + and FADH 2 and CO 2 aerobic conditions citric acid cycle O2O2 H2OH2O ATP ADP + P i fructose galactose

 Sugar substitute: food additive to duplicate sugar taste but with less food energy  Sweetness of compounds many fold greater than glucose or sucrose  Ongoing controversy over health risks

 Saccharin – discovered in 1879 – 300X sweeter than sucrose – no food energy  Aspartame – Discovered in 1965 – 180X sweeter than sucrose aspartame saccharin

 Typical Western diet contains 50 g fructose/day  Fructose found in corn syrup, fruits, and honey  Insulin-independent SUCROSE

 Either hexokinase orfructokinase can covalentlymodify fructose.  Hexokinasephosphorylates glucoserather than fructose,unless [fructose] isunusually high.  Fructokinase found inparticular tissues Fructose metabolism Glycolysis

Fructose metabolism Glycolysis

Lens, kidney, nerve Seminal vesicles

 Occurs in ER and Golgi bodies of human mammary glands Lactose synthase Stimulated by prolactin

Classic galactosemia Uridyltransferase deficiency Autosomal recessive disorder (1 in 23,000 births)