美國醫師執照考試：生物化學(第3版英文)（簡體書）

《美國醫師執照考試叢書：High-Yield生物化學（第3版）》主要特色：1.內容高度概括，重點突出有利於讀者快速掌握學科的核心知識。2.編排新穎、既有基礎知識要點的介紹，又有以疾病為核心的綜合歸納，並體現了相關學科的橫向聯繫。3.語言規範、地道，既有利於讀者快速掌握專業詞匯，又有利於醫學英語思維的培養。
《美國醫師執照考試叢書：High-Yield生物化學（第3版）》是參加美國醫師執照考試的必備輔導用書，也可作為我國醫學院校從事雙語教學的教材和參考用書，對教師進行英語授課，學生學習、參加考試具有重要的參考價值。

《美國醫師執照考試:High-Yield生物化學(第3版)(英文)》是參加美國醫師執照考試的必備輔導用書，也可作為我國醫學院校從事雙語教學的教材和參考用書，對教師進行英語授課，學生學習、參加考試具有重要的參考價值。

Ⅰ Carbobydrate Digestion and Absorption
A.Dietary carbohydrate is digested in the mouth and intestine and absorbed from the small intestine.
B.Disaccharides (e.g.,sucrose,lactose),oligosaccharides (e.g.,dextrins),and polysaccha-rides (e.g.,starch) are cleaved into monosaccharides (e.g.,glucose,fructose).
1.Starch,the storage form of carbohydrate in plants,is hydrolyzed to maltose,mal-totriose,and α-limit dextrins by the enzyme α-amylase in saliva and pancreatic juice.
2.Disaccharides and oligosaccharides are hydrolyzed to monosaccharides by enzymes on the surface of epithelial cells in the small intestine.
C.MONOSACCHARIDES are absorbed directly by carrier-mediated transport.These sug-ars (primarily glucose) travel via the portal vein to the liver for:
1.Oxidation to CO2 and H2O for energy
2.Storage as glycogen
3.Conversion to triglyceride (fat)
4.Release into the general circulation (as glucose)
Ⅱ Glycogen Metabolism
Glycogen,the storage form of carbohydrate in the human body,is found chiefly in the liver and muscle (Figure 5-1).
A.GLYCOGENESIS (glycogen synthesis)
1.Uridine diphosphate-glucose (UDP-glucose) is the activated substrate.
2.The enzyme glycogen synthase adds glucosyl units to the nonreducing ends of existing chains in α-1,4 linkages.
3.The branching enzyme (amylo (1→4) to (1→6) transglycosylase) moves pieces that contain about seven glucose residues from the nonreducing ends of the chains to the interior and creates branches with α-1,6 linkages.
B.GLYCOGENOLYSIS (glycogen breakdown)
1.The enzyme phosphorylase releases units of glucose I-phosphate from the nonre-ducing ends one at a time.
2.The enzyme phosphoglucomutase converts the glacose 1-phosphate to glucose &phosphate.
3.A bifunctional debranching enzyme (4:4-transferase and amylo-l,6-glucosidase)releases glucose residues from the α-1,6 bonds at the branch points.