Pyruvate dehydrogenase complex

CONTENTS What is the pyruvate dehydrogenase complex? Coenzymes of the pyruvate dehydrogenase complex Where is the pyruvate dehydrogenase complex located? Functions of the pyruvate dehydrogenase complex Other sources of acetyl-CoA Sources of pyruvate Mitochondrial pyruvate transport Structure of the pyruvate dehydrogenase complex Structure of pyruvate dehydrogenase or E1 What is the function of the acidic […]

Glycolysis

CONTENTS What is glycolysis? Glycolysis: the first metabolic pathway to be elucidated Why is glycolysis so important? The steps of glycolysis Reaction 1: glucose phosphorylation to glucose 6-phosphate The importance of glucose phosphorylation Other possible fates of glucose 6-phosphate Reaction 2: isomerization of glucose 6-phosphate to fructose 6-phosphate Reaction 3: phosphorylation of fructose 6-phosphate to […]

Gluconeogenesis

CONTENTS What is gluconeogenesis? Why is gluconeogenesis important? Where does gluconeogenesis occur? Irreversible steps of gluconeogenesis From pyruvate to phosphoenolpyruvate Phosphoenolpyruvate precursor: pyruvate or alanine Phosphoenolpyruvate precursor: lactate From fructose 1,6-bisphosphate to fructose 6-phosphate From glucose 6-phosphate to glucose Gluconeogenesis: energetically expensive Coordinated regulation of gluconeogenesis and glycolysis Regulation of gluconeogenesis Pyruvate carboxylase Fructose 1,6-bisphosphatase […]

Cori cycle: definition, function, biochemistry, involved tissues

CONTENTS What is the Cori cycle? Where does the Cori cycle occur? The steps of the Cori cycle Lactate dehydrogenase Other metabolic fates of lactate Energy cost of the glucose-lactate cycle Is the Cori cycle a futile cycle? The Cori cycle and glucose-alanine cycle References What is the Cori cycle? The Cori cycle, or glucose-lactate […]

Gluten: definition, structure, properties, wheat, cereal list

CONTENTS What is gluten? Cereals containing gluten Cereal grain proteins Wheat gluten proteins Gliadins: extensibility and viscosity Glutenins: elasticity and toughness Properties of wheat gluten Gluten-free cereals Oats and gluten References What is gluten? Gluten is not a single protein but a mixture of cereal proteins, about 80% of its dry weight (for example gliadins […]

Digestion of starch and alpha-amylase

Factors affecting relationship between starch and alpha-amylase Amylose and amylopectin, the two families of homopolysaccharides constituting starch, during their biosynthesis within vegetable cells, are deposited in highly organized particles called granules. Granules have a partially crystalline structure and diameter ranging from 3 to 300 µm. The access of the alpha-amylase, the enzyme that catalyzes the […]

Maltodextrin, fructose and endurance sports

Carbohydrate ingestion can improve endurance capacity and performance. The ingestion of different types of carbohydrates, which use different intestinal transporters, can: increase total carbohydrate absorption; increase exogenous carbohydrate oxidation; and therefore improve performance. Glucose and fructose When a mixture of glucose and fructose is ingested (in the analyzed literature, respectively 1.2 and 0.6 g/min, ratio 2:1, for […]

Prolonged exercise and carbohydrate ingestion

During prolonged exercise (>90 min), like marathon, Ironman, cross-country skiing, road cycling or open water swimming, the effects of supplementary carbohydrates on performance are mainly metabolic rather than central and include: the provision of an additional muscle fuel source when glycogen stores become depleted; muscle glycogen sparing; the prevention of low blood glucose concentrations. How many carbohydrates should […]

Carbohydrate ingestion during exercise of relatively short duration and high intensity

Intermittent high intensity exercise and carbohydrate ingestion Carbohydrate ingestion during intermittent high intensity or prolonged (>90 min) sub-maximal exercise can: increase exercise capacity; improve exercise performance; postpone fatigue. The intake of very small amounts of carbohydrates or carbohydrate mouth rinsing (for example with a 6% maltodextrin solution) may improve exercise performance by 2-3% when the […]

Hydration before endurance sports

Dehydration and endurance sports In endurance sports, like Ironman, open water swimming, road cycling, marathon, or cross-country skiing, the most likely contributors to fatigue are dehydration and carbohydrate (especially liver and muscle glycogen) depletion. Pre-hydration Due to sweat loss needed to dissipate the heat generated during exercise, dehydration can compromise exercise performance. It is important to […]

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