Amylopectin: A highly branched glucan in starch.Amylose: An unbranched glucan in starch.Starch Synthase: An enzyme that catalyzes the transfer of glucose from ADPglucose to glucose-containing polysaccharides in 1,4-alpha-linkages. EC 2.4.1.21.1,4-alpha-Glucan Branching Enzyme: In glycogen or amylopectin synthesis, the enzyme that catalyzes the transfer of a segment of a 1,4-alpha-glucan chain to a primary hydroxy group in a similar glucan chain. EC 2.4.1.18.Starch: Any of a group of polysaccharides of the general formula (C6-H10-O5)n, composed of a long-chain polymer of glucose in the form of amylose and amylopectin. It is the chief storage form of energy reserve (carbohydrates) in plants.Isoamylase: An enzyme that hydrolyzes 1,6-alpha-glucosidic branch linkages in glycogen, amylopectin, and their beta-limit dextrins. It is distinguished from pullulanase (EC 3.2.1.41) by its inability to attack pullulan and by the feeble action of alpha-limit dextrins. It is distinguished from amylopectin 6-glucanohydrolase (EC 3.2.1.69) by its action on glycogen. With EC 3.2.1.69, it produces the activity called "debranching enzyme". EC 3.2.1.68.Maltose: A dextrodisaccharide from malt and starch. It is used as a sweetening agent and fermentable intermediate in brewing. (Grant & Hackh's Chemical Dictionary, 5th ed)Glycogen Debranching Enzyme System: 1,4-alpha-D-Glucan-1,4-alpha-D-glucan 4-alpha-D-glucosyltransferase/dextrin 6 alpha-D-glucanohydrolase. An enzyme system having both 4-alpha-glucanotransferase (EC 2.4.1.25) and amylo-1,6-glucosidase (EC 3.2.1.33) activities. As a transferase it transfers a segment of a 1,4-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or another 1,4-alpha-D-glucan. As a glucosidase it catalyzes the endohydrolysis of 1,6-alpha-D-glucoside linkages at points of branching in chains of 1,4-linked alpha-D-glucose residues. Amylo-1,6-glucosidase activity is deficient in glycogen storage disease type III.Glucosyltransferases: Enzymes that catalyze the transfer of glucose from a nucleoside diphosphate glucose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.Phosphotransferases (Paired Acceptors): A group of enzymes that transfers two phosphate groups from a donor such as ATP to two different acceptors. (From Enzyme Nomenclature, 1992) EC 2.7.9.Glucans: Polysaccharides composed of repeating glucose units. They can consist of branched or unbranched chains in any linkages.alpha-Amylases: Enzymes that catalyze the endohydrolysis of 1,4-alpha-glycosidic linkages in STARCH; GLYCOGEN; and related POLYSACCHARIDES and OLIGOSACCHARIDES containing 3 or more 1,4-alpha-linked D-glucose units.DextrinsTrisaccharides: Oligosaccharides containing three monosaccharide units linked by glycosidic bonds.Starch Phosphorylase: An enzyme of the PHOSPHORYLASES family that catalyzes the degradation of starch, a mixture of unbranched AMYLOSE and branched AMYLOPECTIN compounds. This phosphorylase from plants is the counterpart of GLYCOGEN PHOSPHORYLASE in animals that catalyzes the reaction of inorganic phosphate on the terminal alpha-1,4-glycosidic bond at the non-reducing end of glucans resulting in the release of glucose-1-phosphate.Endosperm: Nutritive tissue of the seeds of flowering plants that surrounds the EMBRYOS. It is produced by a parallel process of fertilization in which a second male gamete from the pollen grain fuses with two female nuclei within the embryo sac. The endosperm varies in ploidy and contains reserves of starch, oils, and proteins, making it an important source of human nutrition.Solanum tuberosum: A plant species of the genus SOLANUM, family SOLANACEAE. The starchy roots are used as food. SOLANINE is found in green parts.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Glycogen Storage Disease Type IV: An autosomal recessive metabolic disorder due to a deficiency in expression of glycogen branching enzyme 1 (alpha-1,4-glucan-6-alpha-glucosyltransferase), resulting in an accumulation of abnormal GLYCOGEN with long outer branches. Clinical features are MUSCLE HYPOTONIA and CIRRHOSIS. Death from liver disease usually occurs before age 2.Bacteroidaceae: A family of gram-negative bacteria found primarily in the intestinal tracts and mucous membranes of warm-blooded animals. Its organisms are sometimes pathogenic.