GLYCOLYSIS & OXIDATION OF PYRUVATE Flashcards
Conversion of glucose to pyruvate
Glycolysis
3 stages of glycolysis
Preparatory, cleavage, and payoff phases
What is the net ATP yield from glycolysis?
7 ATP
What enzyme catalyzes the first committed step of glycolysis?
Hexokinase
What is the purpose of phosphofructokinase-1 (PFK-1)?
Regulates glycolysis rate
The product of glyceraldehyde-3-phosphate oxidation?
1,3-Bisphosphoglycerate
The role of pyruvate kinase
Catalyzes final step of glycolysis
What is the byproduct of glycolysis in anaerobic conditions?
Lactate
What is the regulatory molecule that inhibits glycolysis?
ATP
The energy yield from glycolysis?
2 ATP, 2 NADH
What is the product of pyruvate oxidation?
Acetyl-CoA
The coenzyme required for pyruvate oxidation?
Coenzyme A (CoA)
The enzyme complex responsible for pyruvate oxidation?
Pyruvate dehydrogenase complex
What is the purpose of the citric acid cycle?
Generates ATP, NADH, and FADH2
The energy yield from pyruvate oxidation?
12-15 ATP
Regulatory molecule that inhibits pyruvate oxidation?
Acetyl-CoA
What is the byproduct of pyruvate oxidation in aerobic conditions?
ATP, NADH, FADH2
The enzyme responsible for converting pyruvate to acetyl-CoA?
Pyruvate dehydrogenase
What is the purpose of the electron transport chain?
Generates ATP from NADH and FADH2
Enzyme regulating glycolysis rate
Phosphofructokinase-1 (PFK-1)
Enzyme catalyzing glucose phosphorylation
Hexokinase
Electron acceptor in redox reactions
NAD+
Enzyme catalyzing final glycolytic step
Pyruvate kinase
Pyruvate oxidation defects
Lactic acidosis
In yeast, pyruvate glycolysis under anaerobic conditions is decarboxylated and reduced to form a
Ethanol
Process where phosphate is directly donated to ATP from the intermediate pathway
Substrate-level phosphorylation
It has a higher Km than normal plasma concentration of glucose, it is not inhibited by its product glucose-6-phosphate
Glucokinase
Hexokinase is inhibited allosterically by its product
Glucose-6-phosphate
Glucose-6-phosphate is expressed only in:
Liver, kidney, and pancreatic islet
This organ can be both consumer and producer of glucose
Liver
Enolase catalyzes the dehydration of phosphoenolpyruvate, it is inhibited by
Fluoride
Enolase is dependent on the presence of these ions
Mg+ or Mn2+ ions
High glycolytic rate, tissues produce ______ if the pyruvate oxidation is impaired/absent
Lactate
3 nonequilibrium reactions in Glycolysis
Hexokinase, Fructokinase, pyruvate kinase
In erythrocyte, the ________ of ATP formation in Glycolysis may bypass
First site (phosphoglycerate kinase) bypass by biphosphoglycerate mutase
Oxidation of pyruvate to Acetyl-CoA
a irreversible route (Glycolysis - Citric Acid Cycle)
It is regulated by End-Product Inhibition & Covalent Modification
Pyruvate Dehydrogenase
Inhibition of Pyruvate metabolism leads to
Lactic acidosis
Pyruvate dehydrogenase is inhibited by its products:
Acetyl-CoA and NADH
Alcoholic person are?
Thiamin deficient (alcohol inhibits thiamin absorption)
Can be result of defects in one or more of the components of the enzyme complex; present w/ lactic acidosis, particularly after a glucose load
Inherited pyruvate dehydrogenase deficiency
Inherited aldolase A deficiency and pyruvate kinase deficiency in erythrocytes cause:
hemolytic anemia
