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contain the enzyme iduronidase. Glycosaminoglycans accumulate in the lysosomes, swelling them so much that the functioning of the entire cell is impaired. ? Hurler39。氨基己糖脂酶 A ?水解神經(jīng)節(jié)苷脂 GM2D的 223。 ? Secretary lysosome 187 ? 1 granzyme ? 2 不依賴 M6P ? Lysosomes in Health and Disease ? If the cell does not produce a certain lysosomal enzyme or if an enzyme is not properly addressed in the Golgi apparatus, a lysosomal storage disease can result. These diseases are caused by a massive accumulation of material that should have been digested in the lysosome. ? The sorting of lysosomal enzymes in a normal cell (left). First, enzymes receive a chemical address label in the Golgi apparatus (a) and move in vesicles (b) to a lysosome (c). Any enzyme that is accidentally swept out of the cell (d) is recaptured and taken back to the lysosome (e). If some part of the process goes awry, a lysosomal storage disorder can result. ? For example, in Hurler39。高等動物組織的細(xì)胞,大部分的小分子營養(yǎng)物質(zhì)是通過細(xì)胞膜從血液內(nèi)吸收進(jìn)入細(xì)胞;一些分子量大的不能直接通過細(xì)胞膜的物質(zhì),是由內(nèi)吞作用形成吞噬泡或胞飲泡進(jìn)入細(xì)胞內(nèi)。 因此 , 溶酶體也是細(xì)胞內(nèi)的 “ 消化器官 ” 。 ? 老年斑的形成 ? 老年斑的形成 Colorized scanning electron micrograph of a cell ingesting a synthetic particle. Phagocytosis. ? 溶酶體膜的特點(diǎn) : ? (1) 有質(zhì)子泵 ?H H ?H ? 氫離子濃度比細(xì)胞質(zhì)中高出 100倍 ? H ? HH ?H ?H ?H ? (2) 具有多種載體蛋白將水解產(chǎn)物向外運(yùn)轉(zhuǎn) ? (3)膜蛋白高度糖基化 ? 溶酶體的特征酶是酸性磷酸酶 . ? 酶的最適 PH是 5左右 ,少量的溶酶體酶泄漏不會造成細(xì)胞損傷 .主要原因是胞質(zhì)的PH是 . ? 二 溶酶體的功能 ? 1 清除胞內(nèi)和體內(nèi)的垃圾 由于溶酶體中含有豐富的水解酶 , 因此 ,細(xì)胞內(nèi)許多的分解作用都可以由這些水解酶來完成 。 ? 殘留小體有些可通過外徘作用排出細(xì)胞 ,有些則積累在細(xì)胞內(nèi)