The pentose phosphate pathway

CONTENTS What is the pentose phosphate pathway? The elucidation of the pentose phosphate pathway Functions of NADPH and ribose 5-phosphate Where does the pentose phosphate pathway occur? The two phases of the pentose phosphate pathway The steps of the oxidative phase of the pentose phosphate pathway The oxidation of glucose 6-phosphate to 6-phosphoglucono-δ-lactone Catalytic mechanism […]

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 […]

Glucose-alanine cycle

CONTENTS What is the glucose-alanine cycle? The steps of the glucose-alanine cycle The Cahill cycle in skeletal muscle The Cahill cycle in the liver Transaminases Functions of the glucose-alanine cycle Energy cost of the glucose-alanine cycle Similarities and differences between Cahill cycle and Cori cycle References What is the glucose-alanine cycle? The glucose-alanine cycle, or […]

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 […]

Blood glucose levels and liver

Blood glucose levels and hepatic glycogen One of the main functions of the liver is to participate in the maintaining of blood glucose levels within well defined range (in the healthy state before meals 60-100 mg/dL or 3.33-5.56 mmol/L). To do it the liver releases glucose into the bloodstream in: fasting state; between meals; during physical […]

Glycogen: definition, structure and functions

What is glycogen? Glycogen is an homopolysaccharide formed by units of glucose. Chemically similar to amylopectin, and therefore sometimes referred to as animal starch, compared to the latter it is more compact, extensively branched and larger, reaching a molecular weight up to 108 Da corresponding to about 600000 glucose molecules. As in the amylopectin, glucose units in […]

Strategies to maximize muscle glycogen resynthesis after exercise

CONTENTS Post-exercise muscle glycogen synthesis The two phases of muscle glycogen synthesis after exercise The first phase The second phase Muscle glycogen synthesis rate and ingestion of carbohydrates and proteins The two phases: molecular mechanisms Glycogen synthesis rate and insulin Insulin and preferential carbohydrate storage References Post-exercise muscle glycogen synthesis An important energy source for working muscle is its glycogen store, whose level is correlated with […]

Invert sugar: definition, production, uses

What is invert sugar? Invert sugar (also known as inverted sugar) is sucrose partially or totally cleaved into fructose and glucose (also known dextrose) and, apart from the chemical process used (see below), the obtained solution has the same amount of the two monosaccharides. Moreover, according to the product, not cleaved sucrose may also be present. Invert […]

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