Category - Definitions

Query - What definition best describes the term below?

Reversal

Category - Term Recognition

Query - What term does the description below refer to?

(Terms are shown on left, descriptions in middle, figures on right)

Agonist | A substance that mimics the cellular effects of a natural compound (such as a hormone or neurotransmitter) by binding to and activating the same cellular receptor |  | Alkaloids | A large group of nitrogenous basic substances found in plants. Most of them taste bitter, and many are pharmacologically active. They are derived as a result of aromatic amino acid metabolism. |  | Ames Test | A test for the mutagenicity of a substance. A strain of the bacterium Salmonella typhimurium having a mutation that disables an enzyme necessary for histidine utilization is exposed to the substance in question and plated on a medium lacking histidine. A reversion mutation that activates the mutant enzyme causes the cells to grow on this medium. |  | Antagonist | A substance that counteracts the cellular effects of a natural compound (such as a hormone or neurotransmitter) by binding to the cellular receptor for the compound and blocking its action. |  | Antihistamines | Substances used to treat allergies and other inflammations by blocking histamine production. |  | Auxotroph | Microorganism strains that require a particular substance as a nutrient that is not required by the prototype strain. Usually the requirement results from a mutation that disables an enzyme necessary for the endogenous synthesis of the substance. |  | Catecholamines | A class of dihydroxylated molecules, such as dopa, dopamine, norepinephrine, and epinephrine, which are derived from tyrosine in animals. | Figure 21.32 | Chemotaxis | The process by which bacteria sense a concentration gradient of a particular substance in the medium and move either up or down the gradient. |  | Cholinergic Synapse | Synapses in neurotransmission involving acetylcholine | Figure 21.33 | Dopaminergic Neurons | Neurons secreting dopamine |  | Electrical Synapses | Synapses frequently found in animals that live in cold environments that need to make quick motions. These involve direct electrical-ionic conduction between nerve cells, using gap junctions. |  | Endorphins | Small peptides acting as neurohormones that are responsible for the insensitivity to pain that is experienced under conditions of great stress or shock. |  | Enkephalins | Small peptides acting as neurohormones that are responsible for the insensitivity to pain that is experienced under conditions of great stress or shock. Examples include -endorphin, met-enkephalin, and others. |  | Excitatory Neurotransmission | Neurotransmission in which an action potential is promoted in the postsynaptic cell. Examples include nicotinic cholingergic synpses and those involving glutamate. |  | Glutathione S-transferases | Enzymes involved in detoxification of many substances, such as xenobiotics or electrophiles produced through the action of cytyochrome-P-450-linked oxidases. |  | Histidine Operon | A set of 10 bacterial genes for histidine biosynthesis under coordinated transcriptional regulation. |  | Homocystinuria | A condition caused by deficiencies of one of three enzymes in cysteine metabolism. In this patients, homocystine accumulates and is excreted in the urine. | Figure 21.9 | Inhibitory Neurotransmission | Neurotransmission, such as that involving GABA or muscarinic acetylcholine receptors, in which impulses received at a synapse discourages transmission of an action potential in the recipient neuron. |  | Melanocytes | Pigment-producing cells involved in synthesis of melanins |  | Muscarinic Acetylcholine Receptor | A class of receptors for the neurotransmitter acetylcholine that are characterized by an ability to bind the toadstool toxin muscarine. Synapses that have these receptors may be either excitatory or inhibitory. |  | Neurohormones | Substances in nervous systems that modify the way in which nerve cells respond to transmitters. |  | Neurotransmitter | Chemical messenger(s) released by presynaptic nerve cells which bind to postsynaptic cells. |  | NIH Shift | A reaction named after scientists at the National Institutes of Health who described a ring hydroxylation that proceeds via formation of an epoxide intermediate. |  | Ovothiol | A sulfur amino acid found in fertilized eggs that plays a role similar to glutathione |  | Presynaptic axon | Nerve cell carrying action potential to the terminal bulb. | Figure 21.33 | Prototroph | An unmutated form of an organism which is able to synthesize a particular metabolite. Mutation of this type of organism creates an auxotroph. |  | Synaptic Vesicles | Structures on the terminal bulb of the presynaptic axon that release acetylcholine (in cholinergic synapses) in respose to calcium | Figure 21.33 | Terminal bulb (synaptic knob) | Part of the presynaptic axon separated from the postysynaptic dendrite by a synaptic cleft about 20 nm wide. It contains the synaptic vesicles and a change in membrane potential in it causes opening of voltage-gated calcium channels to open, allowing Ca ions to pass from the surrounding space tino the axonal bulb. | Figure 21.33 | Tetrapyrrole | A generic term for compounds containing four linked pyrrole rings. |  | Thyroglobulin | Protein containing tyrosine residues which are iodinated to create thyroid hormone. | Figure 21.19 | Transamination | The enzymatic transfer of an amino group from an amino acid to a keto acid. The keto acid becomes an amino acid and vice versa. |  | Transmethylations | The type of reactions involving most of the group transfers of AdoMet |  | Vacuolar ATPase | An enzyme that pumps protons into synaptic vesicles, an essential step in transporting acetylcholine |

Category - General

Query - What description best fits this enzyme from Chapter 21?

Reversal

Category - Enzymes

Query - What enzyme best fits this description?

(Enzyme on left, description in middle, figures on right)

ALA Dehydratase | Catalyzes joining of two molecules of ALA to form porphobilinogen |  | Amidotransferases | ATP-dependent ligases involved in transferring amide nitrogens (such as from glutamine to form glutamate) |  | Branched Chain -keto acid Dehydrogenase Complex | Multienzyme complex similar in structure to pyruvate dehydrogenase complex that is involved in decarboxylation of leucine, isoleucine, and valine |  | Catecholamine O-methyltransferae (COMT) | Catalyzes an AdoMet-depenednt transmethylation involved in regulating action of adrenergic neurons. |  | Ferrochelatase | An enzyme on the inner mitochondrial membrane that catalyzes addition of iron to form heme from protoporphyrin IX | Figure 21.30 | Monoamine oxidase | A flavoprotein that oxidizes primary amines to aldehydes. Involved in regulating adrenergic neurons. |  | Procollagen proline hydroxylase | Enzyme that catalyzes hydroxyproline formation after the amino acid is in the protein. | Figure 21.4 | Rhodanese | Mitochondrial enzyme catalyzing formation of thiocyanate from thiosulfate and cyanide. The reaction is important for detoxification of cyanide. |  | Serine transhydroxymethylase | Enzyme catalyzing interconversion of glycine and serine. |  | Serine-Threonine Dehydratase | Enzyme catalzing conversion of serine and threonine to pyruvate and -ketobutyrate, respectively. | Figure 21.25 | Sulfite reductase | A bacterial enzyme catalyzing reduction of sulfite to H2S |

Category - General

Query - What description best fits this molecule from Chapter 21?

Reversal

Category - Molecules

Query - What molecule best fits this description?

(Enzyme on left, description in middle, figures on right)

-Ketobutyrate | A breakdown product of methionine and threonine that is also important in synthesis of isoleucine. | Figure 21.8 | Chlorpromazine | A dopamine antagonist which blocks dopamine binding to its receptors. It is used to treat schizophrenia. |  | Mescaline | A product of the peyote cactus known to induce a quasi-schizophrenic state. |  | Acetylcholine Transport Protein | A protein that brings newly synthesized acetylcholine into synaptic vesicles by exchanging it for protons. |  | Lysergic Acid Diethylamide (LSD) | A psychotropic drug that is an indole derivative. It mimics the effects of serotonin at receptors in the central nervous system. |  | Histamine | A substance which, in the stomach, promotes secretion of hydrochloric acid and pepsin. It is a potent vasodilator and, in trauma, contributes to the dangerous lowering of blood pressure that can lead to shock. |  | 1-Aminocyclopropane-1-carboxylic acid | An intermediate in ethylene biosynthesis |  | Propionyl-S-CoA | Arises from an ATP-requiring reaction in which CoASH is added to -ketobutyrate, with decarboxylation, to yield CO 2. | Figure 21.11 | -Mercaptopyruvate | Arises from transfer of the amine group away from cysteine | Figure 21.11 | Difluoromethylornithine | Arrests progression through the cell division cycle. |  | Anthranilate | Derived by transfer of an amine to chorismate with subsequent splitting of lactate | Figure 21.14 | N-5'-Phosphoribosyl-anthranilate | Derived from anthranilate by reaction with PRPP | Figure 21.14 | Prephenic Acid | Derived from chorismate, this molecule is at the fork of pathways for biosynthesis of phenylalanine and tyrosine. | Figure 21.12 | p-Hydroxyphenylpyruvate | Derived from prephenate, it is an immediate precursor of tyrosine. | Figure 21.14 | Cadaverine | Formed by decarboxylation of lysine |  | Phenylpyruvate | Immediate precursor of phenylalanine | Figure 21.14 | Indole-3-glycerol phosphate | Immediate precursor of tryptophan | Figure 21.14 | Kynurenine | Intermediate in tryptophan catabolism derived from N-Formylkynurenine | Figure 21.22 | Homoserine | Metabolic byproduct of aspartate catabolism. It is also a precursor of threonine, isoleucine, and methionine. |  | Glycine betaine | Methyl donor in methionine metabolism |  | -N-trimethyllysine | Methylated amino acid derived from hydrolysis of methylated proteins |  | Cysteine sulfinic acid | Oxidation product of cysteine containing a sulfite | Figure 21.11 | Coniferyl alcohol | Precursor of lignin made from phenylalanine | Figure 21.12 | Diaminopimelic Acid | Precursor of lysine |  | 5,6-Dihydroxyindole | Precursor of melanochrome and the polymeric black melanins. | Figure 21.20 | Uroporphyrinongen III | Produced by combining four molecules of porphobilinogen | Figure 21.30 | Porphobilinogen | Produced by combining two molecules of ALA |  | Leucodopachrome | Produced by nonenzymatic conversion of dopaquinone | Figure 21.20 | -Sulfinylpyruvate | Product resulting from transfer of amine group from cysteine-sulfinic acid. Yields sulfate and pyruvate on breakdown. | Figure 21.11 | Bilirubin diglucuronide | The form in which bilirubin is excreted from the body. | Figure 21.31

Category - Structures

Query - What is the structure of the molecule below?

Reversal

Category - Molecules

Query - What is the name of the molecule with the structure below?

(Molecule on left, structures will be in center, figures on right)

3'-Phosphoadenosine-5'-phosphosulfate (PAPS) |  |  | 3-Phosphoglycerate |  |  | 3-Phosphopyruvate |  |  | 3-Phosphoserine |  |  | Acetoacetate |  | Figure 21.21 | Acetylcholine |  |  | Alanine |  |  | Arginine |  |  | Asparagine |  |  | Aspartate |  |  | Choline |  |  | Cystathionine |  |  | Cysteine sulfinic acid |  | Figure 21.11 | -Aminolevulinic Acid |  | Figure 21.28 | -N-trimethyllysine |  |  | Erythrose-4-phosphate |  | Figure 21.13 | Fumarate |  | Figure 21.21 | Fumarylacetoacetate |  | Figure 21.21 | -Aminobutyric acid |  |  | Glutamate |  |  | Glutamine |  |  | Glutathione |  |  | Glycine betaine |  |  | Histamine |  |  | Homocysteine |  | Figure 21.8 | Homogentisate |  | Figure 21.21 | Homoserine |  |  | Hydroxyproline |  |  | Isoleucine |  |  | Maleylacetoacetate |  | Figure 21.21 | Methionine |  |  | N-acetylglutamate |  |  | N-acetylglutamic -semialdehyde |  |  | N-acetylornithine |  |  | N-Formiminoglutamate |  | Figure 21.23 | NAD+ |  |  | Nicotine |  |  | O-Phosphohomoserine |  |  | Ornithine |  |  | Phenylalanine |  | Figure 21.14 | Phosphoenolpyruvate |  | Figure 21.13 | Proline |  |  | Pyruvate |  | Figure 21.25 | S-Adenosylmethionine (AdoMet) |  |  | Serine |  |  | Serotonin |  |  | Spermidine |  | Figure 21.10 | Spermine |  | Figure 21.10 | Taurine |  | Figure 21.11 | Threonine |  |  | Tryptophan |  | Figure 21.14 | Tyrosine |  | Figure 21.14 | 3,4-Dihydroxyphenylalanine (Dopa) |  | Figure 21.20 | 5,6-Dihydroxyindole |  | Figure 21.20 | -Ketobutyrate |  | Figure 21.8 | Cadaverine |  |  | Indole-3-glycerol phosphate |  | Figure 21.14 | p-hydroxyphenylpyruvate |  | Figure 21.14 | Phenylpyruvate |  | Figure 21.14 | Phosphoribosyl pyrophosphate (PRPP) |  | Figure 21.17 | Thyroxine |  | Figure 21.19 | Triiodothyronine |  | Figure 21.19

Category - Enzymes

Query - What enzyme catalyzes this reaction?

Reversal

Category - Reactions

Query - What catalytic activity does the enzyme below have?

(Enzyme on left, reaction in middle, figures on right)

Acetylcholinesterase | Acetylcholine + H2O <=> Acetate + Choline |  | AdoMet decarboxylase | S-Adenosylmethionine <=> Decarboxylated S-Adenosylmethionine + CO 2 |  | Asparaginase | Asparagine + H2O <=> Aspartate + NH3 |  | Asparagine Synthetase | Aspartate + ATP + NH3 <=> Asparagine + AMP + Ppi |  | Aspartase | Aspartate + H2O <=> Fumarate + NH3 |  | Aspartokinase | Aspartate + ATP <=> -Aspartyl phosphate + ADP |  | Choline Acetyltransferase | Choline + Acetyl-CoA <=> CoASH + Acetylcholine |  | Cystathionine -lyase | Cystathionine + H2O <=> -Ketobutyrate + Cysteine + NH4 |  | Cystathionine Synthase | Homocysteine + Serine <=> Cystathionine + H2O | Figure 21.8 | -aminoleculinic acid synthetase (ALA synthetase) | Glycine + Succinyl-CoA <=> -Aminolevulinic Acid | Figure 21.28 | Dihydropteridine reductase | H2-biopterin + NADPH + H+ <=> H4-biopterin + NADP+ | Figure 21.18 | Dopa decarboxylase | Dopa <=> Dopamine + CO 2 | Figure 21.32 | Dopamine -hydroxylase | Dopamine + O 2 <=> Norepinephrine (requires ascorbic acid) | Figure 21.32 | Glutamate Dehydrogenase | -Ketoglutarate + NH3+NADPH <=> Glutamate + NADP+ |  | Glutamate Synthase | -Ketoglutarate + Glutamine + NADPH <=> 2 Glutamate + NADP+ |  | Glutaminase | Glutamine + H2O <=> Glutamate + NH3 |  | Glutamine Synthase | Glutamate + NH3 + ATP <=> Glutamine +ADP |  | Homogentisic acid dioxygenase | Homogentisate + O 2 <=> Maleylacetoacetate | Figure 21.21 | Methionine Synthase | Homocysteine + 5-methyl-Thf <=> Methionine + Tetrahydrofolate (reaction requires vitamin B12) |  | Synthase | Arginine + O 2 + NADPH + ??? <=> Citrulline + Nitric Oxide |  | p-hydroxyphenylpyruvate dioxygenase | p-Hydroxyphenylpyruvate + O 2 <=< Homogentisate + CO 2 (reaction requires ascorbate) | Figure 21.21 | Phenylalanine hydroxylase | Phenylalanine + O 2 + H4-Biopterin <=> Tyrosine + H2O + H2 Biopterin | Figure 21.18 | Propylaminotransferase I | Putrescine + Secarboxylated S-adenosylmethionine <=> Spermidine + Methylthioadenosine |  | Propylaminotransferase II | Spermidine + Decarboxylated S-adenosylmethionine <=> Spermine + Methylthioadenosine |  | Shikimate Dehydrogenase | 3-Dehydroshikimate + NADPH + H+ <=> D-Shikimate + NADP+ | Figure 21.13 | Threonine Aldolase | Acetaldehyde + Glycine <=> Threonine |  | Threonine Dehydratase | Threonine <=> -Ketobutyrate + NH3 | Figure 21.26 | Tryptophan Oxygenase | Tryptophan + NADPH + O 2 + H+ <=> N-Formylkynurenine + NADP+ + H2O |  | Tryptophan Synthase | Indole-3-glycerol phosphate + Serine <=> Glyceraldehyde-3-phosphate + Tryptophan | Figure 21.14 | Tyrosinase | Tyrosine + O 2 <=> 3,4-Dihydroxyphenylalanine (Dopa) + H2O plus second reaction - Dopa + O 2 <=> Dopaquinone + H2O plus third reaction 5,6-Dihydroxyindole + O 2 <=> Indole-5,6-quinone + 2 H2O | Figure 21.20 | Tyrosine aminotransferase | Tyrosine<=> p-Hydroxyphenylpyruvate | Figure 21.21 | Tyrosine hydroxylase | Tyrosine + O 2 + NADPH + H4-Biopterin + H= <=> Dopa + H2O + NADP+ + H2-Biopterin | Figure 21.32

Category - General

Query - Is contained in the left column below, solution in middle, figure on right

Reversal - there is no reversal

Besides inhibiting ALA synthetase, what other important enzyme in heme biosynthesis is inhibited by heme? | Ferrochelatase |  | Carbon monoxide is produced as a result of what degradative process? | Heme catabolism | Figure 21.31 | Catabolism of tyrosine ulimately leads to production of what two four-carbon compounds? | Fumarate and acetoacetate | Figure 21.21 | Coniferyl alcohol is a metabolic precursor of what two groups of compounds? | Lignin and Flavor components | Figure 21.12 | Cyclic variation of which two molecules in animals regulates their dark/light cycles? | Serotonin and melatonin |  | Deficiency of branched chain -keto acid dehydrogenase complex leads to which disease? | Maple syrup urine disease |  | Deficiency of tyrosinase leads to what condition? | Albinism |  | -Aminolevulinate (ALA) is an important intermediate in which metabolic pathways? | Tetrapyrrole biosynthesis. | Figure 21.27 | How are thyroid hormones synthesized? | By iodination of tyrosine residues in the protein thyroglobulin | Figure 21.19 | How does regulation of aspartokinase occur in E. coli? | There are three forms of the enzyme. Activities of two forms are allosterically inhibited by threonine and lysine, respectively. Synthesis of the third form is inhibited by methionine. |  | How is bilirubin transported in the blood to the liver? | Complexed to serum albumin. | Figure 21.31 | How is -aminobutyric acid made? | Decarboxylation of glutamate |  | How is the relatively insoluble bilirubin altered to make it more soluble for excretion? | Conjugation with two molecules of glucuronic acid | Figure 21.31 | How many nicotinic acetylcholine receptors are in one square micrometer of postsynaptic cholinergic membranes? | 20000 |  | In addition to feedback-inhibition, heme affects production of ALA synthetase by what two other mechanisms? | 1. Translation of ALA synthetase and 2. Translocation from the cytosol into the mitochondrion |  | In heme degradation, what compound arises from action of mixed function oxidase action on heme with subsequent release of iron? | Biliverdin | Figure 21.31 | In humans, deficiency of which enzymes leads to homocystinuria? | Cystathionine synthase or methionine synthase or 5,10-methylenetetrahydrofolate reductase | Figure 21.9 | Jaundice is caused by an accumulation of what heme breakdown product? | Bilirubin | Figure 21.31 | Maple syrup urine disease arises from deficiency of which enzyme? | Branched Chain -keto acid Dehydrogenase Complex |  | Metabolism of which two amino acids leads to confiferyl alcohol, a precursor of lignin? | Phenylalanine, tyrosine | Figure 21.12 | Oxidation of glycine yields which folate? | 5,10-methylenetetrahydrofolate |  | Polymeric red melanins arise from addition of which amino acid to dopaquinone? | Cysteine | Figure 21.20 | Reaction of 5,10-methylenetetrahydrofolate with glycine yields which amino acid? | Serine |  | Serotonin is a precursor of which molecule produced in the pineal gland? | Melatonin |  | Synthesis of nicotinamide nucleotides arise from a branch of the catabolism of which amino acid? | Tryptophan | Figure 21.22 | The condition acute intermitten porphyria arises from a deficiency of what enzyme? | Uroporphyrinogen I synthase |  | The relative amounts of what two pigments accounts for a person's pigmentation? | Red and black melanins. |  | Threonine leads to biosynthesis of which amino acid? | Isoleucine | Figure 21.26 | Transmination of glyoxylate yields which amino acid? | Glycine |  | Valine and Leucine are both derived from which glycolytic intermediate? | Pyruvate | Figure 21.26 | Vitamin C is required by which amino acid-modifying enzyme? | Procollagen proline hydroxylase | Figure 21.4 | When uroporphyrinogen I synthase is deficient, what condition arises? | Acute intermittent porphyria |  | What amino acid requires vitamin B12 for its biosynthesis? | Methionine |  | What are synapses that uses catechloamines called? | Adrenergic |  | What are the four classes of tetrapyrroles? | Heme (and iron porphyrin), chlorophylls, phycobilins, cobalamins (vitamin B12 and derivatives) |  | What are the molecular intermediates between Cysteine/Homoserine and Methionine? | O-succinylhomoserine, cystathionine, homocysteine, methionine | Figure 21.6 | What are the three amino acids found in glutathionine? | Glutamic acid, cysteine, and glycine |  | What are the two most common thyroid hormones? | Triiodothyronine and thyroxine |  | What are two ways in which methylation protects proteins? | 1. Blocking ubiquitination sites, which reduces protein turnover 2. Repair of damaged aspartate residues |  | What C3 and C4 compounds are joined to initiate the shikimic acid pathway? | Erythrose-4-phosphate and Phosphoenolpyruvate | Figure 21.13 | What causes formation of the asymmetric uroporphyrinogen III instead of the symmteric uroporphyrinogen I? | Interaction of uroporphyrinogen I synthase and uroporphyrinogen III cosynthase, which causes one of the rings to flip. |  | What causes pellagra? | Deficiency of nicotinamide. |  | What class of compounds is putrescine the precursor of? | Polyamines |  | What class of molecules is methylated at specific points in the cell cycle? | Histones |  | What compound can lock the acetylcholine receptor in the open configuration? | Nicotine |  | What compound from photorespiration, when oxidized, yields glyoxylate? | Glycolate |  | What compound is capable of blocking the acetylcholine receptor? | d-Tubocurarine (from curare) |  | What compound plays a central role in biosynthesis of methionine in plants and bacteria and in the biosynthesis of cysteine in animals? | Cystathionine | Figure 21.8, Figure 21.6 | What compounds accumulate in the urine of people with phenylketonuria? | Phenylpyruvate, phenyllactate, phenylacetate |  | What compounds can inhibit acetylcholinesterase? | Diisopropyl fluorophosphate, sarin, physostigmine, and parathion. |  | What condition arises from deficiency of nicotinamide? | Pellagra |  | What condition arises from deficiency of the enzyme homogentisic acid dioxygenase? | Alkaptonuria (dark urine disease) |  | What decarboxylation product of ornithine is a precursor of spermidine? | Putrescine |  | What does a deficiency of phynylalanine hydroxylase cause? | Phenylketonuria |  | What effect does binding of acetyl choline have on post synaptic cholinergic receptors? | It opens the ion channels in the postsynaptic membrane, initiating an action potential that can be passed on to the next axon. |  | What effect does calcium have on the presynaptic vesicles? | Release neurotransmitter | Figure 21.33 | What enzyme is a major site of regulation in the pathway from aspartate to homoserine? | Aspartokinase |  | What enzyme is deficient in albinism? | Tyrosinase |  | What enzyme is deficient in alkaptonuria (dark urine disease)? | Homogentisic acid dioxygenase |  | What enzyme is deficient in phenylketonuria? | Phenylalanine hydroxylase |  | What group does decarboxylated S-adenosylmethionine donate in spermine and spermidine synthesis? | Propyl-amino group |  | What group of proteins cycle between being methylated and unmethylated and function in chemotaxis? | Methylatable chemotactic proteins (MCPs) |  | What important classes of compounds in animals trace their metabolism through tyrosine? | Melanines, thyroid hormones, catecholamines |  | What important compound feedback-inhibits ALA synthetase? | Heme |  | What ion activates Synthase? | Ca++ |  | What is H2S used to make in plants and bacteria? | Cysteine | Figure 21.5 | What is the breakdown pathway for methionine? | Methionine -> S-adenosylmethionine -> S-adenosylhomocysteine -> Homocysteine -> (+Serine) -> Cystathionine -> Cysteine + -ketobutyrate |  | What is the condition arising from iodine deficiency called? | Goiter |  | What is the difference between Uroporphyrinogen I and Uroporphyrinogen III? | Uroporphyrinogen I is symmetric and non-functional |  | What is the essential source of sulfur in the animal diet? | Methionine |  | What is the form of the substrate that donates glucuronate for syntheses of bilirubin diglucuronide? | UDP-glucuronate | Figure 21.31 | What is the immediate metabolic precursor of NAD+? | Desamido-NAD+ |  | What is the major control point in heme synthesis? | ALA synthetase |  | What is the metabolic pathway from glutamate to ALA in plants? | Glutamate -> Glutamyl-tRNA -> Glutamate-1-semialdehyde -> ALA | Figure 21.29 | What is the metabolic pathway from tyrosine to epinephrine? | Tyrosine -> dopa -> Dopamine -> Norepinephrine - Epinephrine | Figure 21.32 | What is the molecule PAPS used for? | It is an active agent for sulfate reduction. |  | What is the most abundant porphryin compound in vertebrates? | Heme |  | What is the only known mythyl group transfer that does not involve AdoMet? | Synthesis of methionine, which occurs by transfer of a methyl group from 5-methyltetrahydrofolate or by transfer of a methyl group from glycine betaine to homocysteine. |  | What is the only known reaction of aromatic amino acid biosynthesis in animals? | Biosynthesis of tyrosine from phenylalanine |  | What is the pathway leading from 3-phosphoglycerate to serine? | 3-Phosphoglycerate -> 3-Phosphopyruvate -> 3-phosphoserine -> Serine |  | What is the product of the decarboxylation of ornithine? | Putrescine |  | What metabolic pathway in plants and bacteria is responsible for synthesis of almost all aromatic biological compounds? | Shikimic Acid |  | What methylated amino acid derived from hydrolysis of methylated proteins, is a precusor of carnitine? | -N-trimethyllysine |  | What molecule donates the carbons for methionine biosynthesis? | Homoserine |  | What molecule in tryptophan metabolism is also known as auxin? | Indole-3-acetic acid |  | What molecule is a direct metabolic precursor of p-aminobenzoic acid and coenzyme Q? | Chorismate | Figure 21.12 | What molecule is the biochemical intermediate between glutamic -semialdehyde and Proline? | 1-Pyrroline carboxylic acid |  | What molecule is the ultimate precursor of tetrapyrroles in plants? | Glutamate | Figure 21.27 | What molecule is used by bacteria to reduce sulfate to sulfite? | Thioredoxin |  | What molecules are derived from Chlorophyllide a? | Chlorophylls (plants) and bacteriochlorophyll (bacteria) | Figure 21.27 | What molecules are derived from protoporphyrin IX? | Heme (prokaryotes and eukaryotes) and Phycobilins (algae) | Figure 21.27 | What molecules are derived from the Mg-protoporphyrin IX? | Phycobilins (algae) | Figure 21.27 | What molecules are derived from uroporphyrinogen III? | Cobalamins (bacteria) and Siroheme (component of bacterial sulfite reductase) | Figure 21.27 | What molecules are intermediates in synthesis of ornithine from glutamate? | Glutamate -> N-acetylglutamate -> N-acetylglutamic -semialdehyde -> N-acetylornithine -> Ornithine | Glutamate | What molecules are on the pathway from arginine to creatine phosphate? | Arginine -> Guanidinoacetate -> Creatine -> Creatine Phosphate | Figure 21.3 | What molecules are the ultimate precursors of tetrapyrroles in animals and bacteria? | Glycine and Succinyl-CoA | Figure 21.27 | What organisms are primarily involved in reduction of sulfate for biological use? | Bacteria and plants |  | What pathway does Nitric Oxide stimulate? | cGMP synthesis |  | What pathway leads from homoserine to threonine? | Homoserine -> P-Phosphohomoserine -> Threonine |  | What precursor of dopamine that crosses the blood-brain barrier is used as a treatment of parkinsonism? | Dopa |  | What products result from bacterial catabolism of cysteine? | NH4+, Pyruvate, and H2S | Figure 21.11 | What residues of histones are methylated? | Lysine and arginine |  | What small peptides act as neurotranmsmitters? | Somatostatin, neurotensin, and the enkephalins. |  | What two chemical processes lead from tryptophan to serotonin? | Hydroxylation followed by decarboxylation |  | What two enzymes interconvert glutamate and glutamine? | Glutamine synthetase and Glutaminase |  | What two enzymes are involved in synthesis of uroporphyrinogen III from porphobilinogen? | 1. Uroporphyrinogen I synthase 2. Uroporphyrinogen III cosynthase | Figure 21.30 | What two enzymes can convert -ketoglutarate to glutamate? | Glutamate dehydrogenase and glutamate synthase |  | What two mechanisms are available for synthesis of NAD+? | As a fork in tryptophan catabolism and from the vitamin nicotinic acid. |  | What type of neurotransmitter is associated with parkinsonism? | Dopamine |  | Which amino acid is GABA made from? | Glutamate |  | Which amino acid is the precursor of histamine? | Histidine |  | Which amino acid metabolic pathway involves a nonenzymatic cyclization (via an intramolecular Schiff base)? | Proline biosynthesis |  | Which amino acids serve directly as neurotransmitters? | Glycine and glutamate |  | Which compound derived from glutamate is a neurotransmitter? | -amino butyric acid (GABA) |  | Which enzyme in amino acid biosynthesis contains a tunnel connecting active sites in different subunits? | Tryptophan synthase |  | Which hydroxylated amino acid can be readily converted from an intermediate in glycolysis? | Serine |  | Which intermediate in catabolism of histidine serves as a donor of one-carbon fragments to tetrahydrofolate? | N-Formiminoglutamate | Figure 21.23 | Which modified amino acid is an important component of collagen? | Hydroxyproline (and to a lesser extent, hydroxylysine). | Figure 21.4 | Why are postsynaptic cholinergic receptors referred to as nicotinic acetylcholine receptors? | Because they can bind both acetyl choline and nicotine | Figure 21.34

What substrates and cofactors are necessary for procollagen proline hydroxylase activity? | 1. Procollagen peptide segment containing proline. 2. -ketoglutarate 3. O 2 4. Ascorbic Acid 5. Fe+2 |  | What are the two pathways for biosynthesis of cysteine? | 1. Serine + H2S <=> Cysteine + H2O 2. Serine + Acetyl-CoA -> O-acetylserine + CoASH O-acetylserine + H2S -> Cysteine + Acetate + H2O |  | Describe the pathway by which glutathione helps remove a toxic chemical from the body. | 1. Glutathione reactions with the chemical through the sulfhydryl of cysteine. 2. Glutamate and glycine residues are removed. 3. The compound-cysteine complex remaining is acetylated on the cysteine residue to yield a mercapturic acid derivative of the complex, which is then excreted in the urine. (alternative mechanisms may involve forming methylthio derivatives or a glucuronide). |  | Name 3 molecules made by AdoMet-dependent transmethylation | Possible answers include: Epinephrine Creatine Phosphatidylcholine DNA-N-methyladenine or 5-methylcytosine

Methylated tRNA bases

N1-Methylnicotinamide

Methylated amino acid residues

Category - General

Query - Which neurotransmitters are derived from the following amino acids?

Reversal - there is no reversal

(amino acid on left, neurotransmitter in center, figure on right)

1. Histidine | Histamines |  | 2. Tryptophan | Serotonin |  | 3. Tyrosine | Catecholamines - epinephrine, dopamine, and norepinephrine |

Category - General

Query - Which citric acid cycle intermediate is a direct precursor of the amino acid below?

Reversal - there is no reversal

(amino acid on left, citric acid cycle intermediate in center, figure on right)

Glutamate | -ketoglutarate |  | Aspartate | Oxaloacetate |  | Alanine | Pyruvate |

Category - General

Query - Which amino acid is the amino acid below derived from?

Reversal - there is no reversal

(amino acid on left, solution in center, figure on right)

Asparagine | Aspartate | Figure 21.1 | Lysine | Aspartate | Figure 21.1 | Methionine | Aspartate | Figure 21.1 | Threonine | Aspartate | Figure 21.1 | Isoleucine | Threonine | Figure 21.1 | Proline | Glutamate | Figure 21.1 | Arginine | Glutamate | Figure 21.1 | Histidine | Glutamine | Figure 21.1 | Tryptophan | Glutamine | Figure 21.1 | Glutamine | Glutamate | Figure 21.1