\\\\ Which of the following is not true of the citric acid cycle?
\\ All enzymes of the cycle are located in the cytoplasm, except succinate dehydrogenase, which is bound to the inner mitochondrial membrane.
\\\ Oxaloacetate is used as a substrate but is not consumed in the cycle.
\\\ Succinate dehydrogenase channels electrons directly into the electron transfer chain.
\\\ The Isocitrate dehydrogenase is subject of allosteric regulation by ATP and NADH.
\\\\ Which of the following is an intermediate of the citric acid cycle?
\\\ malonate
\\\ alanine
\\\ acyl-CoA
\\ alpha-Ketoglutarate
\\\\ In mammals, which one is not occur during the citric acid cycle?
\\\ formation of alpha-ketoglutarate.
\\\ generation of NADH and FADH2.
\\\ metabolism of acetate to carbon dioxide and water.
\\ net synthesis of oxaloacetate from acetyl-CoA.
\\\\ What is the net production of conversion of 1 mol of acetyl-CoA to 2 mol of CO2 and CoA via the citric acid cycle?
\\\ 1 mol of citrate.
\\ 1 mol of FADH2.
\\\ 1 mol of NADH.
\\\ 7 mol of ATP.
\\\\ Which one of the following is not associated with the oxidation of substrates by the citric acid cycle?
\\\ CO2 production
\\\ Flavin reduction
\\\ Lipoic acid present in some of the enzyme systems
\\ Pyridine nucleotide oxidation
\\\\ The oxidative decarboxylation of alpha-ketoglutarate proceeds by means of multistep reactions in which all but one of the following cofactors is required. Which one is not required?
\\ ATP
\\\ Lipoic acid
\\\ FAD
\\\ Thiamine pyrophosphate
\\\\ What reaction of the citric acid cycle is most similar to the pyruvate dehydrogenase complex-catalyzed conversion of pyruvate to acetyl-CoA?
\\\ citrate to isocitrate.
\\\ fumarate to malate.
\\\ succinyl-CoA to succinate.
\\ alpha-ketoglutarate to succinyl-CoA.
\\\\ Which one of the following enzymatic activities would be decreased by thiamine deficiency?
\\\ Isocitrate dehydrogenase
\\\ Malate dehydrogenase
\\\ Succinate dehydrogenase
\\ alpha-Ketoglutarate dehydrogenase complex
\\\\ Which reaction of the citric acid cycle is linked to the reduction of FADH2?
\\\ isocitrate dehydrogenase.
\\\ malate dehydrogenase.
\\\ pyruvate dehydrogenase
\\ succinate dehydrogenase.
\\\\ Which of the following cofactors is required for the conversion of succinate to fumarate in the citric acid cycle?
\\\ Biotin
\\ FAD
\\\ NAD+
\\\ NADP+
\\\\ For what reaction is required flavin coenzyme In the citric acid cycle?:
\\\ condensation of acetyl-CoA and oxaloacetate.
\\\ oxidation of fumarate.
\\\ oxidation of isocitrate.
\\ oxidation of succinate.
\\\\ When decreases entry of acetyl-CoA into the citric acid cycle ?
\\\ When [AMP] is high.
\\\ When NADH is rapidly oxidized through the respiratory chain.
\\ When the ratio of [ATP]/[ADP] is high.
\\\ When the ratio of [NAD+]/[NADH] is high.
\\\\ NAD+-specific isocitrate dehydrogenase and alpha-ketoglutarate dehydrogenase are two key regulatory enzymes of the citric acid cycle. What are the inhibitors of these enzymes?
\\\ acetyl-CoA and fructose 6-phosphate.
\\\ AMP and NAD+.
\\\ ATP and NAD+.
\\ ATP and NADH.
\\\\ For what of the following the inner mitochondrial membrane contains a transporter?
\\\ NADH
\\\ Acetyl CoA
\\\ GTP
\\ ATP
\\\\ What is the substrate of isocitrate dehydrogenase?
\\ isocitrate
\\\ citrate
\\\ alpha-ketoglutarate
\\\ succinate
\\\\ In what reaction NADH+H+ is produced?
\\\ succinate dehydrogenase reaction
\\ malate dehydrogenase reaction
\\\ citrate synthase reaction
\\\ aconitase
\\\\ What is the major anaplerotic reaction of TCA cycle?
\\\ alpha ketoglutarate dehydrogenase
\\\ malate dehydrogenase
\\\ enolase
\\ pyruvate carboxylase
\\\\ What is the substrate phosphorylation reaction in TCA cycle?
\\\ formation of NADH+H
\\\ formation of FADH2
\\ formation of GTP
\\\ oxidation of isocitrate
\\\\ What reaction’s product is GTP?
\\\ succinate dehydrogenase reaction
\\\ malate dehydrogenase reaction
\\\ citrate synthase reaction
\\ succinyl CoA synthetase reaction
\\\\ Which of the following is reversible reaction in TCA cycle?
\\\ formation of citrate from acetyl Co A and oxaloacetate
\\\ formation of alpha ketoglutarate from isocitrate
\\ formation of oxaloacetate from malate
\\\ formation of succinyl CoA from alpha ketoglutarate.
\\\\ Which of the following is irreversible reaction in TCA cycle?
\\ formation of citrate from acetyl CoA and oxaloacetate
\\\ formation of malate from fumarate
\\\ formation of oxaloacetate from malate
\\\ formation of fumarate from succinate
\\\\ What enzyme is allosterically inhibited by GTP and succinyl CoA in TCA cycle?
\\\ malate dehydrogenase
\\ alpha-ketoglutarate dehydrogenase
\\\ citrate synthase
\\\ pyruvate dehydrogenase
\\\\ What reaction is catalyzed by pyruvate dehydrogenase complex?
\\\ conversion of glucose into pyruvate
\\ formation of acetyl-CoA from pyruvate
\\\ formation of oxalocetate from pyruvate
\\\ alanine conversion into pyruvate
\\\\ What is characteristic for regulation of pyruvate dehydrogenase complex?
\\\ phosphorylated form of the enzyme is active
\\\ pyruvate dehydrogenase kinase dephosphorylates the enzyme
\\ Ca2+ ions activate the enzyme
\\\ ATP is activator of the enzyme
\\\\ In which compartment of the cell is TCA cycle going?
\\\ cytoplasm
\\\ rough endoplasmic reticulum
\\ mitochondria
\\\ lysosoms
\\\\ How many ATP is formed from NADH+H+ in electron transport chain?
\\\ 2
\\ 2,5
\\\ 3
\\\ 1,5
\\\\ How many ATP is formed from FADH2 in electron transport chain?
\\\ 2
\\\ 2,5
\\\ 3
\\ 1,5
\\\\ How many ATP is formed from TCA cycle with oxidative phosphorylation?
\\\ 10
\\\ 1
\\ 9
\\\ 12
\\\\ How many ATP is formed from TCA cycle with substrate phosphorylation?
\\\ 10
\\ 1
\\\ 9
\\\ 12
\\\\ How many ATP is produced in TCA cycle totally?
\\ 10
\\\ 1
\\\ 9
\\\ 12
\\\\ Which of the following statements about the oxidative decarboxylation of pyruvate in aerobic conditions in animal cells is correct?
\\ One of the products of the reactions of the pyruvate dehydrogenase complex is a thioester of acetate.
\\\ The methyl (—CH3) group is eliminated as CO2.
\\\ The process occurs in the cytosolic compartment of the cell.
\\\ The pyruvate dehydrogenase complex uses all of the following as cofactors: NAD+, lipoic acid, pyridoxal phosphate (PLP) and FAD.
\\\\ The reaction of the citric acid cycle that produces an ATP equivalent (in the form of GTP) by substrate level phosphorylation is the conversion of:
\\\ citrate to isocitrate.
\\ fumarate to malate.
\\\ malate to oxaloacetate.
\\\ succinyl-CoA to succinate.
\\\\ Which of the following reactions is anaplerotic (replenishes intermediate pools) for the citric acid cycle?
\\\ Oxaloacetate + GTP ---- phosphoenolpyruvate + CO2 + GDP
\\\ Malate + NAD+ ---- oxaloacetate + NADH + H+
\\\ Oxaloacetate + acetyl-CoA ----citrate + CoA
\\ Pyruvate + HCO3+ ATP ----oxaloacetate + ADP + Pi + H+
\\\\ Which of the following intermediates is a substrate for the only membrane-associated enzymatic activity in the TCA cycle?
\\\ citrate
\\\ fumarate
\\\ oxaloacetate
\\ succinate
\\\\ The ultimate acceptor of the electrons removed by oxidative decarboxylation in the TCA cycle is:
\\\ NAD+
\\\ FAD
\\\ ATP
\\ O2
\\\\ Which of the following is NOT true of the citric acid cycle:
\\ Most intermediates are activated by phosphorylation.
\\\ It takes place in the mitochondria.
\\\ Many of the reactions are oxidation-reduction reactions.
\\\ It generates GTP by substrate -level phosphorylation
\\\\ The citric acid cycle is amphibolic, that is it functions in both catabolism and anabolism. Certain intermediates are used to make other biomolecules including amino acids, nucleotide bases, fatty acids, and glucose. Several reactions replenish these intermediates for use in the citric acid cycle. These reactions are called:
\\\ Parasynthetic
\\\ Amphipathic
\\ Anaplerotic
\\\ Amphibolic
\\\\ How many NAD is generated in the TCA cycle?
\\\ 1
\\\ 2
\\ 3
\\\ 4
\\\\ How many FADH2 is generated in the TCA cycle?
\\ 1
\\\ 2
\\\ 3
\\\ 4
\\\\ How many ATP are produced after pyruvate oxidation (through the TCA cycle)?
\\\ 10 ATP
\\\ 30-32 ATP
\\ 12,5 ATP
\\\ 7,5 ATP
\\\\ What is the functional group of NAD?
\\\ Izoalloxazine ring
\\ Nicotinamide
\\\ Adenine
\\\ Ribitole
\\\\ How the regulations of metabolic ways generally go?
\\\ By the alterations of intracellular metabolites’ concentration
\\\ By the using of second messengers with peptide hormones
\\\ By repression-induction of the genes
\\ By all of the followings
\\\\ What is the functional group of FAD?
\\ Izoalloxazine ring
\\\ Nicotinamide
\\\ Adenosine residue
\\\ Ribitole residue
\\\\ What is characteristic for TCA cycle?
\\\ Energetical effect of TCA cycle is 8 ATP
\\ TCA cycle goes in aerobic conditions
\\\ The final products are ammonia and water
\\\ 3 ATP are produced in TCA cycle
\\\\ What type of enzyme is Isocitrate dehydrogenase?
\\\ It is regulatory enzyme of glycolysis
\\\ It is FAD-dependent enzyme
\\\ Belongs to transferases
\\ It is decarboxylating dehydrogenase
\\\\ How many macroergic bonds contain ATP?
\\\ 1
\\ 2
\\\ 3
\\\ 4
\\\\ How many macroergic bonds contain ADP?
\\ 1
\\\ 2
\\\ 3
\\\ 4
\\\\ How many macroergic bonds contain AMP?
\\ 0
\\\ 1
\\\ 2
\\\ 3
\\\\ Which of the following is the marcroergic compound?
\\\ AMP
\\ 1,3 bisphosphoglycerate
\\\ Malate
\\\ Glucose-1-phosphate
\\\\ Which of the following belongs to macroergic compounds?
\\\ AMP
\\ ADP
\\\ GMP
\\\ Glucose-1-phosphate
\\\\ What is the delta-G of hydrolytic degradation of ATP?
\\\ -5 kkal/mol
\\ -7,3 kkal/mol
\\\ -14,6 kkal/mol
\\\ -20 kkal/mol
\\\\ Which type of macroergic bond exists in acetyl-CoA?
\\ Tyoesther
\\\ Phospho anhydride
\\\ Phospho enolic
\\\ Phospho amide
\\\\ What is the product of isocitrate dehydrogenase reaction?
\\\ Malate
\\\ Cytrate
\\ Alpha-ketoglutarate
\\\ Succinyl-CoA
\\\\ What is the coenzyme of isocitrate dehydrogenase reaction?
\\\ FAD
\\\ TPP
\\\ CoA
\\ NAD+
\\\\ Which of the following is not necessary for alpha-ketoglutarate dehydrogenase reaction?
\\\ FAD
\\\ CoA
\\\ NAD
\\ ATP
\\\\ What is energetical effect of alpha-ketoglutarate dehydrogenase reaction?
\\\ 2 mole ATP
\\ 2,5 mole ATP
\\\ 3 mole ATP
\\\ 6 mole ATP
\\\\ How many ATP is synthesized in the electron transport chain after isocitrate dehydrogenase reaction?
\\\ 1
\\ 2,5
\\\ 3
\\\ 6,5
\\\\ How many ATP is synthesized in the electron transport chain after succinate dehydrogenase reaction?
\\ 1,5
\\\ 2
\\\ 3,5
\\\ 6
\\\\ How many ATP is synthesized in the electron transport chain after malate dehydrogenase reaction?
\\\ 1
\\ 2,5
\\\ 3
\\\ 6,5
\\\\ Which dehydrogenase is decarboxylating?
\\ Isocitrate dehydrogenase
\\\ malate dehydrogenase
\\\ succinate dehydrogenase
\\\ lactate dehydrogenase
\\\\ Which of the following is not involved in the regulation of TCA cycle?
\\\ Citrate synthatase
\\\ Isocitrate dehydrogenase
\\\ alpha-ketoglutarate dehydrogenase
\\ aconitase
\\\\ Which of the following is not regulatory enzyme of TCA cycle?
\\\ Citrate synthatase
\\ Malate dehydrogenase
\\\ Isocitrate dehydrogenase
\\\ alpha-ketoglutarate dehydrogenase
\\\\ What are regulatory factors of TCA cycle?
\\\ FADH2/FAD
\\\ GTP/GDP
\\ NADH/NAD
\\\ ATP/GTP
\\\\ Which compound is the substrate of TCA cycle?
\\\ NADH
\\\ NADPH
\\ CH3CO-SCoA
\\\
CH3COCOO-\\\\ Succinyl-CoA+ GDP+H3PO4 -- Succinate+GTP+HS-CoA Which enzyme catalyzes this reaction?
\\\ Fumarase
\\ Succinate thyokinase
\\\ Succinate dehydrogenase
\\\ alpha-ketoglutarate dehydrogenase
\\\\ Oxaloacetate+acetyl-CoA + H20 ---- citrate+HS-CoA Which enzyme catalyzes this reaction?
\\\ Isocitrate dehydrogenase
\\\ Fumarase
\\ Citrate synthase
\\\ Succinate thyo kinase
\\\\ Which compounds’ excess amount causes inhibition of oxidation of isocitrate?
\\\ ADP
\\\ NAD
\\ NADH
\\\ FAD
\\\\ Which of the following activates the regulatory enzyme- isocitrate dehydrogenase?
\\\ ATP
\\\ NADH
\\\ CoA
\\ ADP
\\\\ Isocitrate + NAD+ --- alpha-ketoglutarate+CO2+NADH+H+
Which enzyme catalyzes this reaction?
\\ Isocitrate dehydrogenase
\\\ malate dehydrogenase
\\\ pyruvate dehydrogenase
\\\ succinate thyokinase
\\\\ Fumarate+H20 --- malate Which enzyme catalyzes this reaction?
\\\ malate dehydrogenase
\\ fumarase
\\\ alpha-ketoglutarate dehydrogenase
\\\ succinate dehydrogenase
\\\\ Which vitamin’s deficiency influences on TCA cycle?
\\\ Vitamin C
\\ Thiamin
\\\ Biotin
\\\ Vitamin E
\\\\ What is received in TCA cycle by substrate-level phosphorylation?
\\\ UTP
\\\ CTP
\\\ NADH
\\ GTP
\\\\ Which compound inhibits the oxidation of alpha-ketoglutarate?
\\\ ADP
\\\ FAD
\\ Succinyl-CoA
\\\ TPP
\\\\ In the TCA cycle the substrate of succinyl-CoA synthetase is:
\\\ Alpha-ketoglutarate
\\\ Fumarate
\\\ Succinate
\\ Succinyl-CoA
\\\\ In which compartment of the cell the TCA cycle is localized?
\\\ Cytosole
\\\ Outer membrane if mitochondria
\\ In the matrix of mitochondria
\\\ In the nucleus
\\\\ Which conversion is impossible?
\\\ Lactate ---- pyruvate
\\\ Pyruvate ---- lactate
\\ Acetyl-CoA ---- pyruvate
\\\ Alanine ---- pyruvate
\\\\ How many NADH is generated in the process of pyruvate decarboxylation?
\\\ 3
\\\ 4
\\ 1
\\\ 5
\\\\ How many carboxylic groups exist in citrate?
\\\ 1
\\\ 2
\\\ 4
\\ 3
\\\\ What is the irreversible reaction of TCA cycle?
\\\ Malate dehydrogenase
\\\ Fumarase
\\ Alpha-ketoglutarate dehydrogenase
\\\ aconitase
\\\\ What compound is necessary for receiving the citrate from acetyl-CoA in the first reaction of TCA cycle?
\\\ Isocitrate
\\\ Malate
\\ Oxaloacetate
\\\ Succinate
\\\\ What is the source of acetyl-CoA in the body?
\\\ Glycogenesis
\\\ Gluconeogenesis
\\ Beta-oxidation of fatty acids
\\\ Pentose phosphate pathway