What is the primary function of glycolysis?
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Explores key pathways like glycolysis, TCA cycle, and gluconeogenesis, emphasizing their roles and disorders.
Mastering this deck enhances your understanding of critical metabolic processes, enabling accurate diagnosis of metabolic disorders and informed clinical decision-making related to energy metabolism and related diseases.
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| # | Front | Back | Hint |
|---|---|---|---|
| 1 | What is the primary function of glycolysis? | Glycolysis is the metabolic pathway that converts glucose into pyruvate, generating ATP and NADH in the process, serving as the main pathway for glucose utilization in cells. | Think 'glucose to pyruvate' for quick energy. |
| 2 | Which enzyme catalyzes the rate-limiting step of glycolysis? | Phosphofructokinase-1 (PFK-1) catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate, controlling the rate of glycolysis. | Consider 'the brake' enzyme of glycolysis. |
| 3 | Where does the TCA cycle occur, and what is its primary purpose? | The TCA cycle occurs in the mitochondrial matrix and its primary purpose is to oxidize acetyl-CoA to produce NADH, FADH2, and GTP/ATP, which are used in oxidative phosphorylation. | Think 'mitochondrial powerhouse'. |
| 4 | What are the main products of the TCA cycle that supply energy to the cell? | The main products are NADH, FADH2, and GTP (or ATP), which are used in the electron transport chain to generate ATP. | Energy carriers for cellular respiration. |
| 5 | What is gluconeogenesis, and where does it primarily occur? | Gluconeogenesis is the synthesis of glucose from non-carbohydrate precursors like lactate, amino acids, and glycerol, primarily occurring in the liver and to some extent in the kidney. | Think 'making new glucose'. |
| 6 | Which enzyme is unique to gluconeogenesis and bypasses a key glycolytic step? | Pyruvate carboxylase (converts pyruvate to oxaloacetate) and PEP carboxykinase (converts oxaloacetate to phosphoenolpyruvate) bypass the pyruvate kinase step in glycolysis. | Remember 'bypass' enzymes in gluconeogenesis. |
| 7 | How does the Cori cycle contribute to energy metabolism? | The Cori cycle involves the conversion of lactate produced by anaerobic glycolysis in muscles back into glucose in the liver via gluconeogenesis, facilitating continuous energy supply during anaerobic conditions. | Lactate shuttle between muscle and liver. |
| 8 | Which metabolic pathway is primarily responsible for amino acid catabolism and energy production during fasting? | The TCA cycle and associated amino acid degradation pathways facilitate amino acid catabolism, providing substrates for gluconeogenesis and energy production during fasting states. | Think amino acids as alternative fuel. |
| 9 | What is the significance of the enzyme pyruvate dehydrogenase complex (PDC)? | PDC converts pyruvate into acetyl-CoA, linking glycolysis to the TCA cycle; deficiencies lead to lactic acidosis and neurodegeneration. | The gateway from glycolysis to TCA. |
| 10 | Name a common inherited disorder affecting the TCA cycle and its main feature. | Fumarase deficiency; characterized by developmental delay, seizures, and metabolic acidosis due to fumarate accumulation. | Think 'fumarase' as the enzyme affected. |
| 11 | Which pathway is primarily responsible for the synthesis of glucose during fasting? | Gluconeogenesis in the liver is responsible for maintaining blood glucose levels during fasting. | Fasting = liver's glucose factory. |
| 12 | What is a key regulatory hormone that stimulates gluconeogenesis? | Glucagon stimulates gluconeogenesis by activating cAMP-dependent pathways and upregulating key enzymes. | Hormone 'glucagon' promotes glucose production. |
| 13 | What is the clinical significance of a deficiency in glucose-6-phosphatase? | Deficiency causes Von Gierke disease (Glycogen Storage Disease Type I), leading to severe hypoglycemia, lactic acidosis, and hepatomegaly. | Think 'glucose-6-phosphatase' as the final step in glucose release. |
| 14 | Which disease results from a defect in the enzyme pyruvate dehydrogenase? | Pyruvate dehydrogenase deficiency; causes lactic acidosis and neurological deficits due to impaired conversion of pyruvate to acetyl-CoA. | Link between pyruvate and acetyl-CoA disrupted. |
| 15 | How does the malate-aspartate shuttle facilitate mitochondrial NADH transfer into the cytosol? | It transfers electrons from cytosolic NADH into mitochondria via the exchange of malate and aspartate, enabling NADH-dependent processes in the cytosol. | Cytosolic NADH 'hitchhiker'. |
| 16 | What are the clinical features of a deficiency in medium-chain acyl-CoA dehydrogenase (MCAD)? | MCAD deficiency leads to hypoglycemia, hypoketosis, and metabolic crisis during fasting or illness due to impaired fatty acid oxidation. | Think 'fatty acid breakdown issues'. |
| 17 | What role does the enzyme citrate synthase play in metabolism? | Citrate synthase catalyzes the condensation of acetyl-CoA and oxaloacetate to form citrate, initiating the TCA cycle. | First step enzyme in TCA cycle. |
| 18 | Which pathway generates the majority of ATP during aerobic respiration? | Oxidative phosphorylation in the electron transport chain produces the majority of ATP from NADH and FADH2. | Powerhouse of ATP production. |
| 19 | Name a key disorder related to defects in the electron transport chain. | Leber's Hereditary Optic Neuropathy (LHON); causes sudden vision loss due to mitochondrial DNA mutations affecting complex I. | Mitochondrial DNA mutation affecting energy in optic nerve. |
| 20 | Why is the regulation of PFK-1 important in energy metabolism? | PFK-1 controls the rate of glycolysis; its regulation ensures balance between energy supply and demand, influenced by ATP, citrate, and AMP levels. | The 'speed control' for glycolysis. |
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