Amino Acids Proteins, and Enzymes - Hartnell：氨基酸的蛋白质，与酶- Hartnell.pptVIP

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Function of Coenzymes A coenzyme prepares the active site for catalytic activity. * Water-Soluble Vitamins Water-soluble vitamins are soluble in aqueous solutions. cofactors for many enzymes. not stored in the body. Copyright ? 2009 by Pearson Education, Inc. * Fat-Soluble Vitamins Fat-soluble vitamins are A, D, E, and K. are soluble in lipids, but not in aqueous solutions. are important in vision, bone formation, antioxidants, and blood clotting. are stored in the body. * Learning Check Identify each compound as a 1) water-soluble vitamin or 2) fat-soluble vitamin. A. Folic acid B. Retinol (vitamin A) C. Vitamin C D. Vitamin E E. Niacin * Solution Identify each compound as a 1) water-soluble vitamin or 2) fat-soluble vitamin. A. 1 Folic acid B. 2 Retinol (vitamin A) C. 1 Vitamin C D. 2 Vitamin E E. 1 Niacin * Thiamin (Vitamin B1) Thiamin was the first B vitamin identified. is part of the coenzyme thiamin pyrophosphate (TPP), required in the decarboxylation of ?-keto carboxylic acids. deficiency results in beriberi (fatigue, weight loss, and nerve degeneration). Copyright ? 2009 by Pearson Education, Inc. * Riboflavin (Vitamin B2) Riboflavin is made of the sugar alcohol ribitol and flavin. part of the coenzymes flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). needed for good vision and healthy skin. N N N N H H 3 C H 3 C C H 2 C H C H C H C H 2 O H O H O H O H O O D - R i b i t o l * Niacin (Vitamin B3) Niacin is part of the coenzyme nicotinamide adenine dinucleotide (NAD+) involved in oxidation-reduction reactions. deficiency can result in dermatitis, muscle fatigue, and loss of appetite. is found in meats, rice, and whole grains. N C O O H Copyright ? 200