Glucose Transport Systems Quiz

Which glucose transporter is responsible for basal glucose uptake in almost all mammalian cells?

In what type of cells is GLUT-3 the primary glucose transporter?

Which glucose transporter is present in the liver and pancreatic β cells and allows glucose to rapidly enter liver cells only in times of plenty glucose levels?

Which glucose transporter is insulin-dependent and transports glucose into muscle and fat cells?

Which glucose transporter functions primarily as a fructose transporter and is present in the small intestine?

Which glucose transporter in the GLUT family has a Km of around 15-20 mM and plays a role in sensing glucose levels in the pancreas?

Which term best describes the breakdown of 1 molecule of glucose to 2 molecules of pyruvate in the glycolysis pathway?

In which cellular compartment does glycolysis take place?

Which tissues rely primarily on glycolytic breakdown of glucose as their main source of metabolic energy?

What is the main purpose of the Pentose Phosphate Pathway in glucose metabolism?

Under aerobic conditions, what is the fate of pyruvate produced from glycolysis?

What are the characteristics of the preparatory phase of glycolysis?

What are the three enzymes in glycolysis that are potential regulation sites due to catalyzing virtually irreversible reactions?

In glycolysis, what initiates an increase in the amount of glucokinase, phosphofructokinase, and pyruvate kinase in the liver?

What effect does glucagon have on the activity of enzymes like glucokinase, phosphofructokinase, and pyruvate kinase?

Which enzyme is inhibited by high levels of glucose 6-phosphate (G6P), indicating that the cell doesn't require glucose for energy or glycogen synthesis?

What initiates an increase in the synthesis of glucokinase by the liver?

What is the primary function of glycolysis in muscle?

What is the main control site in the mammalian glycolytic pathway?

In muscle functioning anaerobically, why is the inhibitory effect of phosphofructokinase important?

How is pyruvate kinase affected by high levels of ATP?

What is the role of glucokinase in the liver?

How is glucokinase activity regulated in the liver?

What activates phosphofructokinase (PFK) in the liver?

What is the rationale behind the cleavage of F-1,6-Bisphosphate in glycolysis?

Why is Phosphofructokinase-1 in glycolysis considered highly regulated?

What is the purpose of the oxidation of Glyceraldehyde 3-Phosphate to 1,3Bisphosphoglycerate in glycolysis?

Why is the migration of the phosphate important in glycolysis?

Which process in glycolysis involves dehydration of 2-PG to PEP?

What is the primary reason for keeping the concentration of Glyceraldehyde-3-Phosphate low during glycolysis?

Which pathway regenerates NAD+ for further glycolysis under anaerobic conditions?

In what type of cells does the reduction of pyruvate to ethanol occur?

Which pathway involves the reduction of pyruvate to lactate?

What is the fate of pyruvate under aerobic conditions?

Which tissues rely primarily on anaerobic glycolysis for energy production?

Under hypoxic conditions, how is NAD regenerated?

What happens to lactate released from cells undergoing anaerobic glycolysis in the liver?

What is the primary function of the Cori Cycle?

In glycolysis, why is there a need for shuttles like the Glycerol 3-phosphate shuttle?

What is the major function of the Malate–aspartate shuttle in glycolysis?

Which statement accurately describes the fate of lactate in many tissues?

What role does oxygen supply play in determining the fate of lactate in tissues?

Where do glycolytic NADH molecules undergo reoxidation to keep the glycolytic pathway functional?

Which enzyme is responsible for the conversion of malate to oxaloacetate in the malate-aspartate shuttle?

What is the main reason for using the malate-aspartate shuttle for NADH reoxidation in liver, heart, and kidney cells?

Which molecule is not involved in the feeder pathways for glycolysis?

What is the primary function of the glycerol phosphate shuttle in oxidative phosphorylation?

What is the role of glycogen phosphorylase in the feeder pathways for glycolysis?

What is the role of Succinate Dehydrogenase in the TCA cycle?

Where does the citric acid cycle (TCA cycle) primarily occur in eukaryotic cells?

Which stage of cellular respiration involves the generation of GTP?

What is the function of the Pyruvate Dehydrogenase Complex in cellular respiration?

Which enzyme is responsible for the conversion of pyruvate to acetyl-CoA in the mitochondria?

What is the main function of the Citric Acid Cycle (TCA cycle) in cellular metabolism?

What is the role of arsenite in inhibiting the pyruvate dehydrogenase complex?

Which of the following is NOT an advantage of multienzyme complexes like the pyruvate dehydrogenase complex (PDC)?

What is the prosthetic group involved in the inhibition of aconitase by fluorocitrate?

How is Succinate Dehydrogenase different from Isocitrate Dehydrogenase and α-Ketoglutarate Dehydrogenase?

Which enzyme catalyzes the conversion of Succinyl-CoA to Succinate in the TCA cycle?

Why is the hydration of Fumarate to Malate considered a stereospecific trans addition by Fumarase?

What happens in tissues capable of fatty acid synthesis when there is an inhibition of isocitrate dehydrogenase?

What is the consequence of inhibiting α-ketoglutarate dehydrogenase?

What does a rise in mitochondrial Ca2+ levels lead to in terms of pyruvate dehydrogenase activity?

In tissues capable of fatty acid synthesis, what role does insulin play in relation to pyruvate?

What is the significance of a buildup of citrate due to isocitrate dehydrogenase inhibition?

Which enzyme catalyzes the step in the citric acid cycle that involves substrate-level phosphorylation to give GTP?

Which vitamin is required for the citric acid cycle as a precursor to Coenzyme A (CoA)?

What is the net result of the citric acid cycle on a per Acetyl-CoA basis?

Which enzyme is primarily responsible for the regulation of Pyruvate Dehydrogenase Complex through reversible phosphorylation?

Which statement accurately describes the regulation of the Citric Acid Cycle?

Which vitamin functions as a precursor to FAD, an essential cofactor in the citric acid cycle for electron transfer reactions?

What is the main purpose of PEP carboxykinase in gluconeogenesis?

Which enzyme is the first regulatory enzyme in the gluconeogenic pathway?

What source of energy does GTP provide in the conversion of oxaloacetate to phosphoenolpyruvate?

Where does phosphoenolpyruvate carboxykinase (PEPCK) primarily convert oxaloacetate to phosphoenolpyruvate?

What factor determines the relative importance of the two pathways from pyruvate to phosphoenolpyruvate?

What effect does glucagon have on fructose 1,6-bisphosphatase activity in response to low glucose levels?

Which enzyme does glucagon inhibit to decrease the concentration of fructose 2,6-bisphosphate in the liver?

Where is glucagon primarily produced in the body?

What effect does glucagon have on glucose export into the bloodstream from muscle and adipose tissue?

What is the transcriptional effect of glucagon on PEP-carboxykinase?

What is the exception to the rule that glucose cannot be synthesized from fatty acids?

Which molecule can be converted to glucose through the generation of dihydroxyacetone phosphate?

Where does pyruvate carboxylase convert pyruvate into oxaloacetate?

Which enzyme is involved in the first energy-consuming step to convert pyruvate into oxaloacetate?

Which location does glucose 6-phosphatase primarily occupy?

What is the importance of UDPglucose in the conversion of galactose into glucose?

What enzyme catalyzes the reverse reaction of the opposing step in glycolysis during gluconeogenesis?

Which enzyme is responsible for converting Fructose 1,6-bisphosphate to Fructose 6-phosphate in gluconeogenesis?

Where is Glucose 6-phosphatase found in hepatocytes and renal cells?

What is the cost in terms of ATP, GTP, and NADH for producing one molecule of glucose through gluconeogenesis?

Which cells rely ONLY on glucose for ATP generation?

When do the bypasses of fructose bisphosphatase-1 and glucose 6-phosphatase occur in gluconeogenesis?

What effect does increased concentration of acetyl-CoA have on pyruvate carboxylase and the pyruvate dehydrogenase complex in the context of gluconeogenesis?

Under which conditions is pyruvate carboxylase active?

What is the role of Fructose 2,6-Bisphosphate in the liver in terms of glycolysis and gluconeogenesis?

What induces Phosphoenolpyruvate carboxykinase, an enzyme involved in gluconeogenesis?

What is the impact of high ATP and citrate levels on cellular metabolism?

How do glucagon and insulin influence the regulation of gluconeogenesis?

Which enzyme is required for the synthesis of glycogen from UDP-glucose?

What is the high-energy carrier involved in glycogen synthesis?

In glycogen synthesis, what is the function of branching enzyme?

Which enzyme is necessary for the de novo synthesis of a new glycogen molecule in addition to the regular glycogen synthesis enzymes?

What is the activated form of glucose used in glycogen synthesis?

Where does de novo synthesis of glycogen predominantly occur?

Why is glycogen considered a good source of fuel for anaerobic activity?

Where is glycogen principally stored in the body?

What is the significance of the large number of nonreducing ends in glycogen structure?

What is the average distance between branch points in glycogen structure?

How does the regulation of glycogen synthesis and breakdown differ between skeletal muscle and liver cells?

What role does the large number of nonreducing ends play in glycogen metabolism?

What is the primary function of glycogen phosphorylase?

What is the purpose of the debranching enzyme in glycogenolysis?

What is the outcome of the phosphorolysis reaction catalyzed by glycogen phosphorylase?

What is the role of transferase in glycogen breakdown activities?

What is the role of glycogenin in glycogen synthesis?

Which enzyme catalyzes the conversion of Glucose 6-phosphate into Glucose?

What serves as the primer for glycogen synthesis before glycogen synthase takes over?

What is the significance of branching in glycogen regarding its solubility?

Which enzyme forms α-1,6 linkages to facilitate branching in glycogen synthesis?

What is the minimum length of the a-1,4 chain required for branching by glucosyl α-4:6 transferase?

What activates branching enzyme to facilitate branching in glycogen synthesis?

Which enzyme breaks the α-1,4 link and forms α-1,6 linkages in the process of remodeling during glycogen synthesis?

What is the role of transferase in glycogen metabolism?

What is the function of α-1,6-Glucosidase in glycogen metabolism?

What is the fate of glucose 6-phosphate in the liver?

Where are the transferase and α-1,6-Glucosidase activities located in eukaryotes?

In prokaryotes, how is glucose 1-phosphate converted to glucose 6-phosphate?

What enables glucose to leave the liver?

What is the significance of having a large number of nonreducing ends in glycogen structure?

Why is glycogen considered a good source of fuel for anaerobic activity?

In which organelle is glycogen principally stored in the cytosol granules?

How are the branch points structured in glycogen?

What is the main reason for storing glucose as glycogen?

What is the role of glycogen in liver cells?

What enzyme catalyzes the formation of UDP-glucose from Glucose-1-phosphate and UTP during glycogen synthesis?

Which enzyme is essential for catalyzing the attachment of glucose residues in the autoglucosylation process during glycogen synthesis?

In what form is glucose primarily transported during glycogen synthesis?

Which enzyme is responsible for catalyzing the addition of glucose to the nonreducing end during glycogen synthesis?

What is the role of branching enzyme (glucosyl transferase) in glycogen synthesis?

What is the activated form of glucose used in the synthesis of glycogen?

What is the role of glycogenin in glycogen synthesis?

What is the function of branching enzyme in glycogen synthesis?

How does glycogen synthase contribute to glycogen synthesis?

What is the consequence of inhibiting the activity of glycogenin in glycogen synthesis?

How does glycogen branching facilitate both degradation and synthesis processes?

What is the significance of glycogenin remaining permanently attached to the reducing end of the glycogen molecule?

What is the main function of the debranching enzyme in glycogenolysis?

What is the primary role of the phosphorylase enzyme in glycogen metabolism?

What is the significance of branching in glycogen structure?

Which enzyme is responsible for remodeling glycogen to ensure it remains a substrate for degradation?

What process involves the removal of glucosyl residues from the nonreducing ends of the glycogen molecule?

What is the final step in the glycogen breakdown process?

What enzyme works on non-reducing ends until it reaches four residues from an (a1→ 6) branch point in glycogen metabolism?

In eukaryotes, where are the transferase and α-1,6-Glucosidase activities located?

Which enzyme is responsible for converting glucose 1-phosphate to glucose 6-phosphate in prokaryotes?

What enzyme dephosphorylates glucose-6-phosphate in the liver for transport out of the liver?

In which organ can glucose leave due to the presence of glucose 6-phosphatase?

Which enzyme enables glucose to leave the liver by hydrolyzing glucose 6-phosphate?

What is the principal building block of fatty acids?

Which molecule acts as a feedback inhibitor of the enzyme involved in fatty acid synthesis?

What is the source of NADPH in fatty acid synthesis?

Which process is considered the rate-limiting step in the biosynthesis of fatty acids?

Which molecule plays a central role in diverting cellular metabolism towards storage as fatty acids instead of consumption?

What cellular compartment does fatty acid synthesis primarily occur in?

What is the primary function of phosphatidic acid phosphatase in the pathway to TAGs?

In which tissue does glyceroneogenesis coupled with reesterification of FFA control the rate of FA release to the blood?

What is the role of glyceroneogenesis in brown adipose tissue in relation to mitochondria?

During fasting in humans, what percentage of fatty acids reesterified to triacylglycerol is supported by glyceroneogenesis in the liver?

What is the final product formed by transesterification with a third fatty acyl–CoA in the conversion of diacylglycerols to TAGs?

What is the principal form of stored energy in most organisms?

What is the reducing agent in the fatty acid synthetic sequence?

Which enzyme catalyzes the formation of malonyl-CoA from acetyl-CoA?

What specialized lipids serve as pigments and cofactors?

In fatty acid synthesis, what activates the groups on the enzyme-bound -SH groups?

What happens when the fatty acyl chain reaches a length of 16 in the synthesis cycle?

Which fatty acids are essential for mammals and must be obtained from dietary plant material?

What is the precursor of regulatory lipids, the eicosanoids?

Which enzyme is responsible for the formation of fatty acyl esters of glycerol?

What is the central intermediate in lipid biosynthesis that can be converted to either triacylglycerols or glycerophospholipids?

What is the precursor of eicosatrienoate and arachidonate, which can only be made from this specific fatty acid?

What effect does phosphorylation have on acetyl-CoA carboxylase activity?

Where does fatty acid elongation primarily take place?

Which enzyme catalyzes the introduction of double bonds into fatty acid chains?

What is the role of NADPH in fatty acid elongation?

Which fatty acids serve as precursors for the synthesis of palmitoleate and oleate?

What happens to acetyl-CoA carboxylase when it is in its active form?