Upgrade to remove ads
Only $35.99/year

Biochem II Final Practice Questions

Terms in this set (73)

B (Glycogen phosphorylase)
D (Glucagon)
During glycogen degradation, _________ is an example of a regulatory enzyme which is active in the Phosphorylated state. __________ increases the activity of this enzyme by reversible covalent modification.

A. Insulin
B. Glycogen Phosphorylase
C. Phosphoglucomutase
D. Glucagon
A (Phosphoenolpyruvate carboxykinase)
C (GTP)
During gluconeogenesis, oxaloacetate undergoes decarboxylation and phosphorylation in the presence of _____________.
This enzyme uses a ___________ as an energy source.

A. Phosphoenolpyruvate carboxykinase
B. Pyruvate de carboxylase
C. GTP
D. Creating phosphate
A (UDP Glucose)
C (UMP glucose)
___________ is the donor of glucose units during elongation of glycogen fragments. ____________ catalyzes elongation of glycogen linearly.

A. UDP Glucose
B. 4-6 transglucosidase
C. UMP glucose
D. Glycogen synthase
A (Leptin)
What hormone reduces appetite?
A. Leptin
B. Neuropeptide Y
C. A-Melanocytes stimulating hormone
D. Ghrelin
B (Neuropeptide Y)
What hormone sends a signal to eat?
A. Leptin
B. Neuropeptide Y
C. A-Melanocytes stimulating hormone
D. Ghrelin
C (a-melanocytes stimulating hormone)
What hormone works via G protein couple receptor to increase sensation of hunger?
A. Leptin
B. Neuropeptide Y
C. A-Melanocytes stimulating hormone
D. Ghrelin
D (ghrelin)
What hormone works via G protein couple receptor to increase sensation of hunger?
A. Leptin
B. Neuropeptide Y
C. A-Melanocytes stimulating hormone
D. Ghrelin
C (adipose tissue)
Adipokines are released by
A. Liver
B. Pancreas
C. Adipose tissue
D. Muscle
C (Ca)
Opening of voltage gated _______ channels triggers release of insulin
A. Na
B. K
C. Ca
D. Mg
A (UCP-1)
Brown adipose tissue have more mitochondria with what protein?
A. UCP-1
B. B-hydroxybutryate
A (uric acid)
What is seen in gout?
A. Uric acid
B. Ribonucleotide reductase
C (brain)
What is dependent on the salvage pathway?
A. Liver
B. Heart
C. Brain
D. Intestines
D (arginine)
What amino acid is a precursor of Nitric Oxide?
A. Tyrosine
B. Glutamate
C. Histidine
D. Arginine
A (Tyrosine)
What amino acid yield catecholamines such a epinephrine?
A. Tyrosine
B. Glutamate
C. Histidine
D. Arginine
A (B6)
Amino acid decarboxylation requires what B vitamin?
A. B6
B. B7
C. B3
D. B2
C (glutamine)
What is the nontoxic carrier of ammonia
A. Urea
B. Alanine
C. Glutamine
D. Pyruvate
C (Liver)
Site of purine synthesis occurs where
A. Lungs
B. Muscle
C. Liver
D. Adipose
A (IMP -Inosinic acid or inosine monophosphate)
What is the first intermediate in purine synthesis with a full purine ring?
A. IMP
B. PRPP
C. AMP
D. GTP
C (Gut)
What is the site of Nucleic acid degradation
A. Liver
B. Kidneys
C. Gut
A (Molybdenum)
What is the cofactor for xanthoma oxidase?
A. Molybdenum
B. PLP
C. PRPP
A (PRPP - Phosphoribosyl pyrophosphate)
What is an activator of CPS II?
A. PRPP
B. UTP
C (Folic acid)
What vitamin deficiency leads to reduced thymidylate synthesis?
A. Cobalamin
B. Niacin
C. Folic acid
D. Riboflavin
E= Pancreatic Lipase
S= Triacylglycerol
If products of a digestive enzymatic reaction include 2-monoacylglycerol and Free Fatty acids, the enzyme involved in this reaction is ___E___. The substrate of this reaction is ___S___

E= Pancreatic Lipase
E= Phospholipase A2
S= Phospholipid
S= Triacylglycerol
A. (ATP-ADP Translocase)
B. (Atractyloside)
The inner mitochondrial membrane contains ________ which mediates the passage of nucleotides. _________ inhibits the activity of this enzyme

A. ATP-ADP Translocase
B. Atractyloside
C. Citrate
D. Citrate synthase
A (HMG-CoA reductase)
C (Mevalonate)
Statins inhibit _________, the rate limiting enzyme of cholesterol biosynthesis. This enzyme catalyzes the conversion of HMG-CoA to ________

A. HMG-CoA reductase
B. HMG synthase
C. Mevalonate
D. Malonyl CoA
A (FAD)
B (Dehydrogenation)
__________ is an example of a catabolic electron carrier which is derived from vitamin B2. This electron carrier helps in __________ reactions

A. FAD
B. Dehydrogenation
C. Acyl group transfer
D. CoA
B. (QH2)
C. (Cytochrome C)
___________ is the electron donor in Complex III. During Q cycle, there is transfer of electrons to a mobile heme protein called ___________. This heme protein shuttles between complex III and IV.

A. Cytochrome a
B. QH2
C. Cytochrome C
D. NADH
C. (Glyceraldehyde 3-Phosphate dehydrogenase)
D. (1,3-Bisphosphoglycerate)
In glycolysis, __________ catalyzes the NADH generating step. This step generates a high energy Phosphorylated intermediate called _________

A. Glucose 6-phosphate dehydrogenase
B. 2-Phosphoglycerate
C. Glyceraldehyde 3-Phosphate dehydrogenase
D. 1,3-Bisphosphoglycerate
A. (Oxaloacetate)
D. (Pyruvate carboxylase)
________ is a 4C citric acid cycle intermediate which serves as a precursor for aspartate and glucose. The level of this molecule is maintained in the mitochondrial matrix via ______ activity

A. Oxaloacetate
B. Succinate
C. Succinate dehydrogenase
D. Pyruvate carboxylase
B. (Peroxidase)
C. (Cycloxygenase)
During Eicosanoid biosynthesis, oxidation and cyclization of Arachidonic acid by PGH2 synthase occurs mainly due to __________ and __________ enzyme activates

A. Hormone sensitive lipase
B. Peroxidase
C. Cycloxygenase
D. Phospholipase A2
B. (Carnitine Acyl transferase I)
D. (Fatty acyl-carnitine)
Malonyl CoA inhibits the activity of __________, an enzyme which is localized in the outer mitochondrial membrane. This function of this enzyme is to convert cytoplasmic Fatty acyl CoA to __________, which in turn moves into the mitochondrial matrix.

A. Succinyl CoA
B. Carnitine Acyl transferase I
C. Succinyl CoA transferase
D. Fatty acyl-carnitine
D. (Cytochrome oxidase)
B. (Cyanide)
_________ acts as a proton pump. ___________ inhibits the flow of electrons from complex IV to the terminal electron acceptor

A. Succinate dehydrogenase
B. Cyanide
C. Malonate
D. Cytochrome oxidase
A= Fructose 1-phosphate
B= Glyceraldehyde 3-phosphate
In the liver, fructokinase in the presence of ATP converts fructose to ___________. The product of fructokinase metabolizes into two 3-carbon molecules which enter glycolysis pathway as ________

A= Fructose 1-phosphate
A= Fructose 1,6-bisphosphate
B= 3-Phosphoglycerate
B= Glyceraldehyde 3-phosphate
D. (Insulin)
A. (Dephosphorylation)
In the presence of high blood glucose, _________ activates Acetyl coA carboxylase. Insulin causes __________ of the enzyme.
A. Dephosphorylation
B. Phosphorylation
C. Glucagon
D. Insulin
A. (Tyrosine)
C. (PLP)
_________ is the amino acid precursor of catecholamines. Aromatic amino acid decarboxylase in the presence of _________ converts DOPA to dopamine
A. Tyrosine
B. Valine
C. PLP
D. THF
A. (Elongation and desaturation)
B. (Endoplasmic reticulum)
Dietary linoleic acid undergoes __________ to become C20:4 molecule called Arachidonic acid. This process occurs in the __________
A. Elongation and desaturation
B. Endoplasmic reticulum
C. Cytoplasm
D. Hydrolysis and oxidation
B. (GLUT2)
D. (Glucokinase)
In the liver, __________ allows the uptake of glucose from circulation. __________ is an inducible enzyme which has a high Km for glucose and is not subject to inhibition by glucose 6-phosphate
A. GLUT4
B. GLUT2
C. Hexokinase I
D. Glucokinase
B. (Release)
C. (NADH)
Catabolism involved degradation of macromolecules with the _________ of energy. An example of catabolic coenzyme in its reduced state is _______
A. Input
B. Release
C. NADH
D. NADH2
B. (Xanthine oxidase)
A. (Uric acid)
Allopurinol is used for treating Gout. It inhibits a molybdenum containing enzyme called _________. Inhibition of this enzyme reduces the formation of _________
A. Uric acid
B. Xanthine oxidase
C. Adenosine deaminase
D. Adenine
B. (Lipoic acid)
A. (Transfer of Acetyl group to CoA)
E2 subunit of pyruvate dehydrogenase complex contains ____________ as the coenzyme that is bound covalently to lysine. It catalyzes the __________
A. Transfer of Acetyl group to CoA
B. Lipoic acid
C. FAD
D. Regeneration of oxidized lipoamide
A. (Catabolic)
B. (Fatty acid oxidation)
Energy status of a cell is important for metabolic regulation. When the energy status of the cell is low ___________ pathways predominate. ____________ is an example of such a pathway.
A. Catabolic
B. Fatty acid oxidation
C. Anabolic
D. Fatty acid synthesis
A. (Acetyl coA)
D. (Oxaloacetate)
Diabetic ketosis results from diverting _________ from citric acid pathway to initiate glucose synthesis by gluconeogenesis. Accumulation of _________ in the liver leads to the formation of ketone bodies.
A. Acetyl coA
B. Propionyl CoA
C. Citrate
D. Oxaloacetate
D. (Citrate)
C. (Citrate lyase)
Transport of Acetyl CoA from mitochondria to cytosol occurs via ________ shuttle. _________ is an ATP requiring enzyme important for regeneration of Acetyl CoA in the cytosol
A. Citrate synthase
B. Malate aspartate
C. Citrate lyase
D. Citrate
A. (CDP-Diacylglycerol)
D. (CTP)
_________ is the NTP source which forms activated intermediates during glycerophospholipids synthesis. ________ is an example of an activated intermediate during glycerophospholipid synthesis
A. CDP-Diacylglycerol
B. 2,3 Bisphosphoglycerate
C. UTP
D. CTP
B. (Glutamine)
C. (ATP)
In purine de novo pathway, Inosinate generates GMP in the presence of _________ and _________
A. GTP
B. Glutamine
C. ATP
D. Aspartate
A. (Acyl CoA dehydrogenase)
B. (FAD)
________ catalyzes the first oxidation reaction in the beta-oxidation of fatty acids. This enzyme has several isozymes each specific for fatty acids of different chain lengths. ________ is the catabolic electron carrier in this reaction.
A. Acyl CoA dehydrogenase
B. FAD
C. Enoyl coa hydratase
D. NAD+
A. (Ribonucleotide reductase)
D. (NADPH)
__________ is the enzyme which forms deoxyribonucleotides from ribonucleotides. The electron donor for this reaction is______
A. Ribonucleotide reductase
B. NADH
C. DNA Polymerase I
D. NADPH
B. (Glycogen synthase)
C. (Insulin)
_________ is a regulatory enzyme in glycogen synthesis. _________ increases the expression of this enzyme in the muscle.
A. Glucagon
B. Glycogen synthase
C. Insulin
D. Glucose 6-phosphatase
C. (A-ketogluterate)
B. (NADH)
In citric acid cycle, ________ is a 5-carbon intermediate formed by oxidation
decarboxylation of the substrate. The enzyme catalyzing this step also generates _______
A. FADH2
B. NADH
C. A-ketogluterate
D. Isocitrate
A. (Enteropeptidase)
D. (3)
_________ is a small intestine enzyme that activates Trypsinogen to Trypsin.
Tryptic digestion of a peptide containing the following sequence Gly-Pro-Leu-Arg-His-Ala-Lys-Glu-GIn-Val-lle-Tyr will release _______ oligopeptides.
A. Enteropeptidase
B. Pepsin
C. 2
D. 3
A. (TPP)
D. (NADH)
subunit of Pyruvate dehydrogenase complex contains ________ coenzyme. High ________ levels inhibit the activity of this enzyme.
A. TPP
B. THF
C. NAD+
D. NADH
B. (Lipoprotein lipase)
A. (Apo C-II)
_________ hydrolyzes dietary Triacylglycerols from Chylomicrons and release fatty acids for energy use in myocytes.
Apoprotein __________ activates this enzyme.

A. Apo C-II
B. Lipoprotein lipase
C. Apo C-III
D. Pancreatic Lipase
D. (Phosphoenolpyruvate)
B. (Phosphoenolpyruvate carboxykinase)
During gluconeogenesis, _________ is the GTP requiring enzyme. This catalyzes the conversion of Oxaloacetate to ________
A. Malate
B. Phosphoenolpyruvate carboxykinase
C. Malate dehydrogenase
D. Phosphoenolpyruvate
C. (Phosphoglycerate kinase)
D. (1,3-bisphosphoglycerate)
During glycolysis, _________ catalyzes the first substrate level phosphorylation step. This enzyme converts ________ to 3-Phosphoglycerate.
A. Phosphoglycerate mutate
B. 2-phosphoglycerate
C. Phosphoglycerate kinase
D. 1,3-bisphosphoglycerate
C. (Glutamate and a-ketoglutarate)
A. (PLP)
Alanine transaminase catalyzes the transfer of NH2 group from Alanine to Pyruvate and involves _________ pair. Transaminases use _______ as a coenzyme.
A. PLP
B. NAD+
C. Glutamate and a-ketoglutarate
D. Phenylalanine and fumarate
D. (Succinyl CoA synthetase)
C. (Succinate and GTP)
In citric acid cycle, ________ catalyzes substrate level phosphorylation. During this enzymatic reaction, cleavage of thioester linkage of the substrate generates ________
A. Succinate dehydrogenase
B. Fumarate and FADH2
C. Succinate and GTP
D. Succinyl CoA synthetase
C. (Formyl tetrahydrofolate)
B. (5-phosphoribosylamine)
During de novo purine biosynthesis, _________ is the single carbon carrier which donates one of the carbon in the purine ring. Synthesis of _________ from PRPP and glutamine is the rate limiting step in purine biosynthesis.
A. Methylene tetrahydrofolate
B. 5-phosphoribosylamine
C. Formyl tetrahydrofolate
D. Dihydroorotate
B. (Insulin)
C. (Fructose 2,6-bisphosphate)
___________ causes dephosphorylation of Phosphofructokinase-2 (PFK-2). The dephosphorylated form of the enzyme is important for the synthesis of ___________ an activator of Phosphofructokinase-1
A. Glucagon
B. Insulin
C. Fructose 2,6-bisphosphate
D. Fructose 1,6-bisphosphate
C. (Phenylalanine hydroxylase)
B. (Tyrosine)
Deficiency of __________ results in Phenylketonuria. In this disease, _________ becomes a conditionally essential amino acid.

A. Isoleucine
B. Tyrosine
C. Phenylalanine hydroxylase
D. Phenylalanine aminotransferase
B. (ATP)
C. (Citrate)
Inhibitors of PFK-1 include:
A. Fructose 1,6 bisphosphate
B. ATP
C. Citrate
D. AMP
A. (NADH)
B. (Complex I)
Malate aspartate shuttle delivers electrons from cytosolic NAH into mitochondria as ____________. These electrons enter at _________ of the electron transport chain. Heart and liver use this shuttle for their functions.
A. NADH
B. Complex I
C. Complex II
D. FADH2
A. (Thymidylate synthase)
C. (Methylenetetrahydrofolate)
_________ catalyzes the methylation of dUMP to dTMP. This enzyme requires __________ as a coenzyme.
A. Thymidylate synthase
B. Methionine synthase
C. Methylenetetrahydrofolate
D. PLP
A. (B-alanine)
D. (UMP)
Orotidylate undergoes decarboxylation to form _________. One of the intermediates of pyrimidine catabolism is ________
A. B-alanine
B. TMP
C. Citrulline
D. UMP
A (ATP)
D (Acetyl CoA)
Inhibitors of Pyruvate kinase include:
A. ATP
B. Fructose 1,6 bisphosphate
C. AMP
D. Acetyl CoA
B. (Glutamine)
C. (Mitochondria)
_________ is the predominant amino acid in circulation which transports ammonia. In urea cycle, carbomylphosphate is formed from CO2, NH3 and ATP by carbomylphosphate synthetase I which is present in the ________

A. Arginine
B. Glutamine
C. Mitochondria
D. Cytoplasm
D. (UDP-glucose pyrophosphorylase)
B. (UDP-glucose)
During glycogen synthesis, ________ converts glucose 1-phosphate to Pi. This enzyme generates an activated glucose carrier called _________
A. Limit dextrin
B. UDP-glucose
C. Glucose 6-phosphates
D. UDP-glucose pyrophosphorylase
C. (Salvage pathway)
B. (PRPP)
During starvation, brain uses ________ to recycle purines and pyrimidines. In this pathway, adenine reacts with this high energy intermediate called __________ to form AMP.
A. De novo pathway
B. PRPP
C. Salvage pathway
D. GTP
B. (Glucose 6-phosphate)
C. (NADPH)
Oxidation of ________ can occur via Glycolysis or Pentose Phosphate Pathway. Its metabolic fate depends on the intracellular _________ concentration.

A. NAD+
B. Glucose 6-phosphate
C. NADPH
D. Ribose 5-phosphate
B. (Phosphofructokinase-1)
C. (Fructose 1,6-bisphosphatase-1)
________ catalyzes the rate limiting enzyme of glycolysis. The bypass of this step during gluconeogenesis involves __________ to generate Fructose 6-phosphate and Pi.

A. Malate dehydrogenase
B. Phosphofructokinase-1
C. Fructose 1,6-bisphosphatase-1
D. Hexokinase
B. (Phosphoenolpyruvate)
D. (-7.5 kcal/mol)
A. 2-phosphoglycerate
B. Phosphoenolpyruvate
C. -22.1 kcal/mol
D. -7.5 kcal/mol
A (Epinephrine)
C. (Hormone sensitive lipase + perilipin)
_________ increases fat mobilization in adipose tissue. This occurs mainly because of phosphorylation of _________
A. Epinephrine
B. Insulin
C. Hormone sensitive lipase + perilipin
D. Lipoprotein lipase + colipase
A. (Glucagon)
D. (Glycogen phosphorylase)
__________ stimulates breakdown of glycogen. It causes phosphorylation of _________ enzyme.
A. Glucagon
B. 4:6 transferase
C. Insulin
D. Glycogen phosphorylase
A=AMP-dependent protein kinase
B= Fatty acid synthesis
Low energy status activates ___A_____. This enzyme inhibits ____B_____
A= HMG CoA reductase
A=AMP-dependent protein kinase
B= Fatty acid synthesis
B= Fatty acid degradation
Students also viewed