Carbohydrate Metabolism I Flashcards
Oxidation of Sugar
gives you acids and ketons.
Reduction of Sugar
gives you hexitols
Phosphorylation of sugar
in cell, glucose phosphorylated right away by hexokinase into G6P. In liver glucose phosphorylated right away by glucokinase
Amination of sugars
F6P started synthesis of aminosugar N-acetyl-glucosamine, imporant part of extracelluar matrix
Sulfation of sugars
Sulfated sugars found in large proteoglycan molecules that make up the ECM. Sulfotransferase enzymes add sulfate froups to C6, C4, or C2 on carbs.
Maltose
Glucose + Glucose. alpha 1,4 bond
Sucrose
Fructose + Glucose, alpha 1, beta 2 bond
Lactose
Galatose + Glucose, beta 1,4 bond
UDP- glucose
needed for glycogen formation reactions
UDP- glucoronic acid
needed for liver detox reactiosn
Glycosidic bonds
made between activated sugar nucleotide and substrate
Glycogen
alpha 1,4 linkages between glucose monomers with brances at alpha 1,6 linkages. animal glucose storage
Amylose
alpha 1,4 linkages between glucose monomers. Found in starch.
Cellulose
beta-linkages between glucose monomers. FOund in plants
Polysaccharid breakdown
1) alpha-amylase cleaves alpha-glycosidic bonds randomly
2) in small intestine, alpha-lucosidase and isomaltase further break down alpha-limit dextrin and maltase hydrolyzes maltose into 2 glucoses
3) Maltotriose broken down by oligosacchrides
What is sugar broken down by
sucrase/isomaltase
Raffinose
sugar that is abundant in seeds, cannnot be digested by humans
Uptake of Glucose/Galactose
brought into small intestine through SGLT1 active sympotor. Goes into circulation through GLUT2. In cell, glucose is phosphorylated by hexokinase to G6P and galactose is phosphorylated by galactokinas eot rate it
Uptake of Fructose
brought into small intestine epithelium through GLUT 5 channel. Then into circulation through facilitated diffusion (NO ATP) once in liver, phosphorylated by fructokinase
