Category - Definitions

Query - What definition best describes the term below?

Reversal - this is not a simple reversal, so I've split the reversal into two parts. The part that follows is the second part.

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

Acyl-CoA | Most common form in which acyl groups react in synthesis of acylated lipids. | Figure 19.2 | Acyltransferases | Enzymes which catalyze transfer of acyl groups in synthesis of lipids. |  | Adrenocorticotropic Hormone (ACTH) | A hormone whose release is stimulated by corticotropin-releasing hormone, it stimulates the synthesis of the mineralocorticoids and glucocorticoids in the adrenal cortex. |  | Androgens | A group of steroid hormones (androstenedione and testosterone) which promote male sexual development and maintain male sex characteristics. | Figure 19.24 | Arachidonic Acid | An eicosanoid (all-cis-5,8,11,14-eicosatetraenoic acid) that is a precursor of most of the prostaglandins and thromboxanes. |  | Aspirin (acetylsalicylic acid) | A non-steroidal anti-inflammatory drug that acts by acetylating PGH synthase to inhibit its cyclooxygenase activity. |  | Bathorhodopsin | The name of the all-trans-retinal-opsin complex formed by light induced isomerization of rhodopsin. | Figure 19.27 | Bile Acids | A class of compounds derived from cholesterol with detergent properties. They serve to emulsify dietary lipids in the intestine and promote fat digestion and absorption. | Figure 19.23 | Bile Salt | Compound formed by combining a bile acid in amide linkage to an amino acid. |  | Bradykinin | A hormone that can stimulate release of arachidonic acid. |  | Cholecalciferol (Vitamin D3) | The most abundant form of vitamin D. It is not required in the diet and arises by ultraviolet light conversion of 7-dehydrocholesterol, an intermediate in cholesterol biosynthesis. |  | Cholestanol | A fully saturated derivative of cholesterol. | Figure 19.17 | cis-Polyisoprene | A polyprenol that is in natural rubber. | Figure 19.28 | Corticotropin-releasing Hormone (CRH) | A hormone released from cells in the hypothalamus in response to central nervous system input. It stimulates release of corticotropin or adrenocorticotropic hormone (ACTH). |  | Diacylglycerol | A molecule containing a glycerol esterified to two acyl groups. |  | Diethylstilbestrol | A synthetic estrogen, used at one time to promote growth of beef cattle, that is a potential carcinogen. |  | Diterpene | A term for a terpene derived from geranylgeranyl pyrophosphate | Figure 19.28 | Eicosanoids | A class of compounds derived from C20 polyunsaturated fatty acids. They include the prostaglandins, thromboxanes, and leukotrienes. |  | Enterohepatic Circulation | A pathway taken by bile acids in the body. In it, the bile acids are secreted in the upper small intestine, absorbed in the lower small intestine, and returned to the liver for reuse through the portal blood |  | Estrogens | A group of steroid hormones (estrone and estradiol), which support female sexual characteristics. | Figure 19.24 | Ether Phospholipids | Lipids that contain an alkyl (or alkenyl) group, rather than an acyl group, linked to one of the oxygen atoms of glycerol in a phospholipid. |  | Exocytosis | A process transFerring a compound outside of a cell. |  | Fatty Acid Hydroperoxides | Oxidized verions of fatty acids created by interaction with superoxides. |  | Gibberellic Acid | A diterpene that is a plant growth hormone. | Figure 19.28 | Glucocorticoids | A group of steroid hormones that includes cortisol and corticosterone, which promote gluconeogenesis and, in pharamacological doses, suppress inflammation reactions. | Figure 19.24 | Glycerophospholipids (phosphoglycerides) | Lipids based on glycerol that also contain a phosphate. They are found primarily as components of membranes. |  | Glycosphingolipids | A class of sphingolipids containing carbohydrate(s). It includes cerebrosides and gangliosides | Figure 19.13 | Hydroxyperoxyeicosaenoic Acids | Molecules that serve as precursors to the leukotrienes |  | Isoprene | A generalized five-carbon compound that is a building block of the isoprenoids. |  | Isoprenoids (terpenes) | A class of lipids made by putting together isoprene units. It includes the steroids, bile acids, lipid soluble vitamins, and others. |  | Juvenile hormone I | A sesquiterpene that controls metamorphosis in insects. | Figure 19.28 | LDL Receptor | A cellular receptor that plays an important role in regulating cholesterol levels in the bloodstream. |  | Leukotriene A4 | Leukotriene formed from 5-HPETE. | Figure 19.32 | Leukotriene B4 | Leukotriene formed from Leukotriene A4 | Figure 19.32 | Leukotriene C | One of the leukotrienes that is a potent muscle contractant and is thought to be involved in the pathogenesis of asthma through constriction of small airways in the lung. |  | Leukotriene C4 | Leukotriene formed from Leukotriene B4 by addition of glutathione. | Figure 19.32 | Limonene | A monoterpene responsible for the characteristic odor of lemons. | Figure 19.28 | Lipid-Soluble Vitamins | A group of four vitamins, A,D,E, and K that are all isoprenoids. |  | Lung Surfactant | A lipid and protein containing substance secreted from lung. By maintaining high surface tension, it prevents collapse of the alveoli when air is expelled. It contains 50%-60% dipalmitoylphosphatidylcholine |  | Lycopene | A tetraterpene that is a tomato pigment. | Figure 19.28 | Melittin | A protein in bee venom that stimulates arachidonate release. |  | Metarhodopsin II | Produced from bathorhodopsin by loss of a proton and conformational changes, this is the species that activates transducin to initiate the visual cascade process. | Figure 19.27 | Mineralocorticoids | A group of steroid hormones (aldosterone) which regulate ion balance by promoting reabsorption of sodium, chloride, and bicarbonate in the kidney. | Figure 19.24 | Monoterpene | A term for a terpene derived from geranyl pyrophosphate. | Figure 19.28 | Myelin Sheath | A multilayered structure that protects and insulates cells of the central nervous system. |  | Opsin | A protein in the lamellar protein disks of rod cells of the eye that binds to 11-cis-retinal. | Figure 19.26, Figure 19.27 | Perhydrocyclopentanophenanthrene | Chemical form of the root compound of the steroids | Figure 19.17 | Phosphoinositides | The class of molecules encompassing the different phosphorylated forms of phosphatidylinositol. Some members of the family are important in transmembrane signaling. | Figure 19.8 | Plasmalogens | Phospholipids that contain an alkenyl ether at position 1 of glycerol. |  | Polyprenols (polyisoprenoid alcohols) | A term for an isoprenoid with more than 50 carbons. | Figure 19.28 | Progestins | A group of steroid hormones which regulate events during pregnancy and are the precursors to all other steroid hormones. |  | Respiratory Distress Syndrome | A condition in infants which are unable to either synthesize or secrete lung surfactant. |  | Retinoids | Compounds derived from retinol |  | Rhodopsin | The name of the 11-cis-retinal-opsin complex in the rod cells of the eye. | Figure 19.27 | Sesquiterpene | A term for a terpene derived from farnesyl pyrophosphate. | Figure 19.28 | Sphingolipidoses | A group of congenital diseases also known as lipid storage diseases which is characterized by deficiency of one of the degradative enzymes for a sphingolipid, leading to accumulation of the sphingolipid in the lysosomes. | Table 19.1 | Sphingolipids | Lipids, typically found in nervous tissue in animals, that are based on sphingosine. They are also found in plants and yeast. |  | Steroid Hormones | A group of hormones (five major classes) derived from cholesterol. | Figure 19.24 | Steroids | Lipids which are derived from cholesterol. |  | Sterol | A class of steroids with an alcohol group. It includes cholesterol |  | Tetraterpenes | A term for a terpene derived from four geranyl pyrophosphates. | Figure 19.28 | transducin | A G protein that receives the visual signal from metarhodopsin to start the visual cascade. |  | Zellweger Syndrome | A rare autosomal recessive disorder in which peroxisomes are absent and plasmalogen synthesis is severely deficient. Individuals with this condition suffer damage to brain, liver, and kidney, before reaching an early death. |

Category - Term Recognition

Query - The description below best matches what term from Chapter 19?

Reversal - this is the partial reversal of above set

Description in middle, terms on left, figures on right.

1,25-Dihydroxycholecalciferol | A molecule made in kidney from 25-hydroxycholcalciferol. The reaction is stimulated by parathyroid hormone when calcium levels are low. It is the hormonally active form of vitamin D |  | 25-hydroxycholecalciferol | A molecule which arises from hydroxylation of cholecalciferol at carbon 25. |  | 5-hydroperoxyeicosatetraenoic acid (5-HPETE) | Intermediate in leukotriene produced by action of 5-lipoxygenase on arachidonic acid. |  | 7-dehydrocholesterol | An intermediate in cholesterol biosynthesis that is a precursor of cholecalciferol, vitamin D3. |  | Acyl-ACP | Donor of acyl groups in bacterial synthesis of phosphatidic acid from glycerol-3-phosphate. | Figure 19.3 | Acyl-CoA | Most common form in which acyl groups react in synthesis of acylated lipids. | Figure 19.2 | AcyltransFerases | Enzymes which catalyze transFer of acyl groups in synthesis of lipids. |  | Adrenocorticotropic Hormone (ACTH) | A hormone whose release is stimulated by corticotropin-releasing hormone, it stimulates the synthesis of the mineralocorticoids and glucocorticoids in the adrenal cortex. |  | All-trans-retinal | Form of vitamin A released by metarhodopsin II after signal has been sent to activate transducin. | Figure 19.27 | Androgens | A group of steroid hormones (androstenedione and testosterone) which promote male sexual development and maintain male sex characteristics. | Figure 19.24 | Arachidonic Acid | An eicosanoid (all-cis-5,8,11,14-eicosatetraenoic acid) that is a precursor of most of the prostaglandins and thromboxanes. |  | Aspirin (acetylsalicylic acid) | A non-steroidal anti-inflammatory drug that acts by acetylating PGH synthase to inhibit its cyclooxygenase activity. |  | Bathorhodopsin | The name of the all-trans-retinal-opsin complex formed by light induced isomerization of rhodopsin. | Figure 19.27 | -Carotene | A precursor of vitamin A in the diet. It is abundant in carrots | Figure 19.25 | Bile Acids | A class of compounds derived from cholesterol with detergent properties. They serve to emulsify dietary lipids in the intesting and promote fat digestion and absorption. | Figure 19.23 | Bile Salt | Compound formed by combining a bile acid in amide linkage to an amino acid. |  | Bradykinin | A hormone that can stimulate release of arachidonic acid. |  | Cholecalciferol (Vitamin D3) | The most abundant form of vitamin D. It is not required in the diet and arises by ultraviolet light conversion of 7-dehydrocholesterol, an intermediate in cholesterol biosynthesis. |  | Cholestanol | A fully saturated derivative of cholesterol. |  | cis-Polyisoprene | A polyprenol that is in natural rubber. | Figure 19.28 | Corticotropin-releasing Hormone (CRH) | A hormone released from cells in the hypothalamus in response to central nervous system input. It stimulates release of corticotropin or adrenocorticotropic hormone (ACTH). |  | Diacylglycerol | A molecule containing a glycerol esterified to two acyl groups. |  | Diethylstilbestrol | A synthetic estrogen, used at one time to promote growth of beef cattle, that is a potential carcinogen. |  | Diterpene | A term for a terpene derived from geranylgeranyl pyrophosphate | Figure 19.28 | Eicosanoids | A class of compounds derived from C20 polyunsaturated fatty acids. They include the prostaglandins, thromboxanes, and leukotrienes. |  | Enterohepatic Circulation | A pathway taken by bile acids in the body. In it, the bile acids are secreted in the upper small intestine, absorbed in the lower small intestine, and returned to the liver for reuse through the portal blood |  | Estrogens | A group of steroid hormones (estrone and estradiol), which support female sexual characteristics. | Figure 19.24 | Ether Phospholipids | Lipids that contain an alkyl (or alkenyl) group, rather than an acyl group, linked to one of the oxygen atoms of glycerol in a phospholipid. |  | Exocytosis | A process transFerring a compound outside of a cell. |  | Fatty Acid Hydroperoxides | Oxidized verions of fatty acids created by interaction with superoxides. |  |  |  |  | Glucocorticoids | A group of steroid hormones that includes cortisol and corticosterone, which promote gluconeogenesis and, in pharamacological doses, suppress inflammation reactions. | Figure 19.24 | Glycerophospholipids (phosphoglycerides) | Lipids based on glycerol that also contain a phosphate. They are found primarily as components of membranes. |  | Glycosphingolipids | A class of sphingolipids containing carbohydrate(s). It includes cerebrosides and gangliosides | Figure 19.14 | Hydroxyperoxyeicosaenoic Acids | Molecules that serve as precursors to the leukotrienes |  | Ibuprofen | A non-steroidal anti-inflammatory drug that acts by inhibiting the cyclooxygenase activity of a PGH synthase different from the one inhibited by aspirin . |  | Isoprene | A generalized five-carbon compound that is a building block of the isoprenoids. |  | Isoprenoids (terpenes) | A class of lipids made by putting together isoprene units. It includes the steroids, bile acids, lipid soluble vitamins, and others. |  | Juvenile hormone I | A sesquiterpene that controls metamorphosis in insects. | Figure 19.28 | LDL Receptor | A cellular receptor that plays an important role in regulating cholesterol levels in the bloodstream. |  | Leukotriene A4 | Leukotriene formed from 5-HPETE. | Figure 19.32 | Leukotriene B4 | Leukotriene formed from Leukotriene A4 | Figure 19.32 | Leukotriene C | One of the leukotrienes that is a potent muscle contractant and is thought to be involved in the pathogenesis of asthma through constriction of small airways in the lung. |  | Leukotriene C4 | Leukotriene formed from Leukotriene B4 by addition of glutathione. | Figure 19.32 | Limonene | A monoterpene responsible for the characteristic odor of lemons. | Figure 19.28 | Lipid-Soluble Vitamins | A group of four vitamins, A,D,E, and K that are all isoprenoids. |  | Lung Surfactant | A lipid and protein containing substance secreted from lung. By maintaining high surface tension, it prevents collapse of the alveoli when air is expelled. It contains 50%-60% dipalmitoylphosphatidylcholine |  | Lycopene | A tetraterpene that is a tomato pigment. | Figure 19.28 | Melittin | A protein in bee venom that stimulates arachidonate release. |  | Metarhodopsin II | Produced from bathorhodopsin by loss of a proton and conformational changes, this is the species that activates transducin to initiate the visual cascade process. | Figure 19.27 | Mineralocorticoids | A group of steroid hormones (aldosterone) which regulate ion balance by promoting reabsorption of sodium, chloride, and bicarbonate in the kidney. | Figure 19.24 | Monoterpene | A term for a terpene derived from geranyl pyrophosphate. | Figure 19.28 | Myelin Sheath | A multilayered structure that protects and insulates cells of the central nervous system. |  | Opsin | A protein in the lamellar protein disks of rod cells of the eye that binds to 11-cis-retinal. | Figure 19.26, Figure 19.27 | Perhydrocyclopentanophenanthrene | Chemical form of the root compound of the steroids | Figure 19.16 | Phosphoinositides | The class of molecules encompassing the different phosphorylated forms of phosphatidylinositol. Some members of the family are important in transmembrane signaling. | Figure 19.8 | Plasmalogens | Phospholipids that contain an alkenyl ether at position 1 of glycerol. |  | Polyprenols (polyisoprenoid alcohols) | A term for an isoprenoid with more than 50 carbons. | Figure 19.28 | Progestins | A group of steroid hormones which regulate events during pregnancy and are the precursors to all other steroid hormones. |  | Respiratory Distress Syndrome | A condition in infants which are unable to either synthesize or secrete lung surfactant. |  | Retinoids | Compounds derived from retinol |  | Rhodopsin | The name of the 11-cis-retinal-opsin complex in the rod cells of the eye. | Figure 19.27 | Sesquiterpene | A term for a terpene derived from farnesyl pyrophosphate. | Figure 19.28 | Sphingolipidoses | A group of congenital diseases also known as lipid storage diseases which is characterized by deficiency of one of the degradative enzymes for a sphingolipid, leading to accumulation of the sphingolipid in the lysosomes. | Table 19.1 | Sphingolipids | Lipids, typically found in nervous tissue in animals, that are based on sphingosine. They are also found in plants and yeast. |  | Steroid Hormones | A group of hormones (five major classes) derived from cholesterol. | Figure 19.24 | Steroids | Lipids which are derived from cholesterol. |  | Sterol | A class of steroids with an alcohol group. It includes cholesterol |  | Tetraterpenes | A term for a terpene derived from four geranyl pyrophosphates. | Figure 19.28 | transducin | A G protein that receives the visual signal from metarhodopsin to start the visual cascade. |  | Triacylglycerol | Another name for a fat or oil. It contains glycerol esterified to three acyl groups. |  | Triterpene | A term for a terpene derived from two farnesyl pyrophosphates | Figure 19.28 | TxB2 | A thromboxane derived by hydrolysis of TxA2 |  | Undecaprenol Phosphate | A polyprenol that is a sugar carrier for oligosaccharide synthesis. | Figure 19.28 | Vitamin A | An isoprenoid alcohol that is also called all-trans-retinol. The aldehyde form (retinal) also plays a key role in vision. |  | Vitamin D | The only vitamin derived from cholesterol. It acts like a prohormone, because it is converted to a metabolite that acts analogously to a steroid hormone. It is active in regulating calcium and phosphorus metabolism, particularly with respect to synthesis of the inorganic matrix of bone. |  | Vitamin K | A vitamin originally discovered as a lipid-soluble substance involved in blood coagulation. |  | Vitamin K2 (menaquinone) | A form of vitamin K found in animals and bacteria. It has a partly unsaturated side chain. The compound is essential for the carboxylation of glutamate residues in certain proteins to give -carboxyglutamate. This modification allows a protein to bind calcium. Binding of calcium is an essential event in the blood clotting cascade. |  | Zellweger Syndrome | A rare autosomal recessive disorder in which peroxisomes are absent and plamalogen synthesis is severely deficient. Individuals with this condition suffer damage to brain, liver, and kidney, before reaching an early death. |

Category - Enzymes

Query - What enzyme best fits the description below?

Reversal

Category - General

Query - Describe the function(s) of this enzyme in the cell.

(enzyme on left, function/description in center, figures on right)

5-Lipoxygenase | Enzyme that catalyzes initial step in the formation of leukotrienes from arachidonic acid. | Figure 19.32 | Cholesterol Desmolase | An enzyme complex that hydroxyolates the side chain of cholesterol at carbons C-20 and C-22, resulting in cleavage at that point and production of pregnenolone. |  | Cyclase | Catalyzes conversion of squalene-2,3-epoxide to lanosterol | Figure 19.22 | Cytochrome P-450 | A mixed function oxidase which converts cholesterol to 7--hydroxycholesterol, an intermediate on the pathway to making bile acids. | Figure 19.23 | PGH Synthase | An enzyme which acts on free arachidonate to create PGH2. It is a heme containing enzyme. | Figure 19.30 | Retinal Isomerase | Enzyme that converts all-trans-retinal to 11-cis-retinal for combination with opsin. | Figure 19.27 | Squalene monooxygenase | Catalyzes conversion of squalene to squalene-2,3-epoxide using O 2, NADPH, and H+ | Figure 19.22

Phospholipase A2 | An enzyme implicated in release of arachidonate from phosphatidylethanolamine or phosphatidylcholine in prostaglandin metabolism. | Figure 19.6 | Phospholipase C | An enzyme implicated in acting on phosphatidylinositol to yield a diacylglycerol, which in turn undergoes cleavage to give free arachidonate in prostaglandin metabolism. | Figure 19.6

HMG-CoA Reductase | This enzyme is the most important enzyme regulating synthesis of cholesterol. Its synthesis is inhibited transcriptionally by cholesterol (or a hydroxylated derivative) and the activity of the enzyme is controlled by cyclic phosphorylation and dephosphorylation |

Category - General

Query - Describe the molecule below.

Reversal

Category - Molecules

Query - What molecule from Chapter 19 best fits this description?

(molecule on left, function in center, figures on right)

Triacylglycerol | Another name for a fat or oil. It contains glycerol esterified to three acyl groups. |  | Triterpene | A term for a terpene derived from two farnesyl pyrophosphates | Figure 19.28 | TxB2 | A thromboxane derived by hydrolysis of TxA2 |  | Undecaprenol Phosphate | A polyprenol that is a sugar carrier for oligosaccharide synthesis. | Figure 19.28 | Vitamin A | An isoprenoid alcohol that is also called all-trans-retinol. The aldehyde form (retinal) also plays a key role in vision. |  | Vitamin D | The only vitamin derived from cholesterol. It acts like a prohormone, because it is converted to a metabolite that acts analogously to a steroid hormone. It is active in regulating calcium and phosphorus metabolism, particularly with respect to synthesis of the inorganic matrix of bone. |  | Vitamin K | A vitamin originally discovered as a lipid-soluble substance involved in blood coagulation. |  | Vitamin K2 (menaquinone) | A form of vitamin K found in animals and bacteria. It has a partly unsaturated side chain. The compound is essential for the carboxylation of glutamate residues iin certain proteins to give -carboxyglutamate. This modification allows a protein to bind calcium. Binding of calcium is an essential event in the blood clotting cascade. |

Ibuprofen | A non-steroidal anti-inflammatory drug that acts by inhibiting the cyclooxygenase activity of a PGH synthase different from the one inhibited by aspirin . |

Gibberellic Acid | A diterpene that is a plant growth hormone. | Figure 19.28

All-trans-retinal | Form of vitamin A released by metarhodopsin II after signal has been sent to activate transducin. | Figure 19.27

-Carotene | A precursor of vitamin A in the diet. It is abundant in carrots | Figure 19.25

1,25-Dihydroxycholecalciferol | A molecule made in kidney from 25-hydroxycholecalciferol. The reaction is stimulated by parathyroid hormone when calcium levels are low. It is the hormonally active form of vitamin D |  | 25-Hydroxycholecalciferol | A molecule which arises from hydroxylation of cholecalciferol at carbon 25. |  | 5-Hydroperoxyeicosatetraenoic acid (5-HPETE) | Intermediate in leukotriene produced by action of 5-lipoxygenase on arachidonic acid. |  | 7-Dehydrocholesterol | An intermediate in cholesterol biosynthesis that is a precursor of cholecalciferol, vitamin D3. |

Deoxycholate | A bile acid abundant in the bile of some mammals. It is widely used as a laboratory reagent, to solubilize membrane proteins. |  | Glycocholate | A bile salt formed by linking cholic acid to glycine. | Figure19.23 | Taurocholate | A bile salt formed by linking cholic acid to taurine. | Figure 19.23 | Phytosphingosine | A compound that is the root of plant sphingolipids. |  | S-Adenosylmethionine (AdoMet) | A donor of methyl groups in metabolic pathways. One such pathway is synthesis of phosphatidylcholine from phosphatidylethanolamine. | Figure 19.2 | Farnesyl pyrophosphate | A fifteen-carbon intermediate in isoprenoid biosynthesis formed by joining isopentenyl pyrophosphate with geranyl pyrophosphate (with release of a pyrophosphate). | Figure 19.20 | Vitamin K1 (phylloquinone) | A form of vitamin K found in plants. The molecule has a long saturated side chain. |  | Phosphatidylcholine | A glycerophospholipid made either by methylation of phosphtidylethanolamine or by joining the choline phosphate of CDP-choline with a diacylglycerol. | Figure 19.2, Figure 19.5 | Squalene | A linear 30 carbon precursor of lanosterol in the isoprenoid biosynthetic pathway. It contains six isoprene units and is formed from presqualene pyrophosphate by reduction (by NADPH), with release of a pyrophosphate. | Figure 19.21 | Pregnenolone | A molecule that is a product of reaction of cholesterol with the cholesterol desmolase enzyme comple. It is oxidized to progesterone. |  | Sphingomyelin | A sphingolipid formed by linking choline (from phosphatidylcholine) to a ceramide. Is an abundant component of nerve membranes. | Figure 19.12 | Ceramides | A sphingolipid made by linking acyl group to the amine of sphinganine. | Figure 19.12 | Geranyl pyrophosphate | A ten-carbon intermediate in isoprenoid biosynthesis formed by joining dimethylallyl pyrophosphate and isopentenyl pyrophosphate (with release of a pyrophosphate) | Figure 19.20 | Presqualene Pyrophosphate | A thirty-carbon intermediate in isoprenoid biosynthesis formed by joining two farnesyl pyrophosphates (with release of a pyrophosphate). | Figure 19.21 | TxA2 | A thromboxane originally isolated from thrombocytes (blood platelets) as a compound that stimulated platelet aggregation, an early step in blood clotting. |  | Vitamin E (-tocopherol) | A vitamin that primarily appears to function as an antioxidant, particularly in preventing attack of peroxides on unsaturated fatty acids in membrane lipids. |  | CDP-diacylglycerol | Activated nucleotide-containing precursor of most of the phosphatidyl glycerophospholipids. | Figure 19.2 | Lysolecithin | Also known as 1-acylglyerophosphorylcholine. It can be created by action of phospholipase A2 on phosphatidylcholine. |  | 1-Alkyl-2-acylglycerol-3-phosphate | An ether phospholipid created by acylation of 1-alkylglycerol-3-phosphate. | Figure 19.11 | Choline | An immediate precursor of phosphocholine in one metabolic pathway leading to phosphatidylcholine. | Figure 19.5 | 3-ketosphinganine | An intermediate in sphingolipid synthesis formed by combining the palmitate group of palmitoyl-CoA with serine. The carboxyl group of serine is lost in the process. | Figure 19.13 | Sphinganine | An intermediate in sphingolipid synthesis that is formed by reduction of 3-ketosphinganine by NADPH. | Figure 19.13 | Phosphocholine | An intermediate made from choline that reacts with CTP to form CDP-choline | Figure 19.5 | Lecithin | Another name for phosphatidylcholine |  | Cerebroside | Class of sphingolipid formed by linking a glucose (from UDP-glucose) to a ceramide. Is abundant in brain tissue. | Figure 19.13 | Lanosterol | Cyclized molecule derived from squalene that is a precursor of other steroids, including cholesterol. | Figure 19.22 | Phosphatidylinositol | Glycerophospholipid made from CDP-diacylglycerol by replacing the CDP with inositol. Is an important precursor of molecules used in transmembrane signalling. | Figure 19.2 | Phosphatidylserine | Lipid made from CDP-diacylglycerol by replacing CDP with a serine. | Figure 19.4 | Phosphatidylglycerol | Molecule created by hydrolyzing the phosphate from phosphatidylglycerol-3-phosphate | Figure 19.4 | 1-Alkylglycerol-3-phosphate | Molecule created by reduction of 1-alkyldihydroxyacetone phosphate by NADPH. Is produced on the pathway to synthesis of ether phospholipids. | Figure 19.11 | Phosphatidylethanolamine | Molecule made either by removing the carboxyl group from serine in phosphatidylserine or by replacing the serine with ethanolamine by the enzyme, phosphatidylethanolamine serine transFerase. | Figure 19.4 | Phosphatidylglycerol-3-phosphate | Molecule made from CDP-diacylglycerol by replacing the CDP with glycerol phosphate. | Figure 19.4 | Cardiolipin | Molecule made from phosphatidylglycerol by replacing the glycerol of one phosphatidylglycerol by another phosphatidylglycerol. A prominent glycerophospholipid in heart tissue. | Figure 19.4 | 1-Alkyldihydroxyacetone phosphate | Molecule produced by reductive replacement of the acyl group of 1-acylhydroxyacetone phosphate en route to synthesis of alkyl ether phospholipids. | Figure 19.11 | 1-acyldihydroxyacetone phosphate | Molecule that can lead to either synthesis of phosphatidic acid or to ether phospholipids | Figure 19.11 | Phosphatidic Acid | Molecule that is an immediate precursor of CDP-diacylglycerol and triacylglycerols. | Figure 19.2 | S-Adenosylhomocysteine (AdoHcy) | Molecule that remains after S-adenosylmethionine donates its methyl group. |  | Cholic acid | One of the most abundant human bile acids, along with chenodeoxycholic acid. | Figure 19.23 | Chenodeoxycholic acid | One of the most abundant human bile acids, along with cholic acid. | Figure 19.23 | Isopentenyl pyrophosphate | One of two isoprene building blocks. Formed by decarboxylation of 3-phospho-5-pyrophosphomevalonate. | Figure 19.19 | Dimethylallyl pyrophosphate | One of two isoprene building blocks. Formed from isopentenyl pyrophosphate by reorganization of the double bond within the molecule. | Figure 19.19 | Mevalonate | Six-carbon compound formed by NADPH reduction of 3-hydroxy-3-methylglutaryl-CoA (with release of CoASH), it is a precursor of 5-phosphomevalonate and is part of the isoprenoid biosynthetic pathway. | Figure 19.19 | 5-Pyrophosphomevalonate | Six-carbon compound in the isoprene biosynthetic pathway formed by phosphorylation of 5-phosphomevalonate. | Figure 19.19 | 3-Phospho-5-pyrophosphomevalonate | Six-carbon compound in the isoprene biosynthetic pathway formed by phosphorylation of 5-pyrophosphomevalonate. | Figure 19.19

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)

HMG-CoA Reductase | 3-hydroxy-3-methylglutaryl-CoA + 2NADPH + 2H+ <=> Mevalonate + CoASH + 2NADP+ | Figure 19.19 | -1-Alkyl Desaturase | 1-alkyl-2-acylglycerol-3-phosphate + NADH + H+ + O 2<=> Plasmalogen + 2H 2 O + NAD+ | Figure 19.12 | Phospholipase A1 | An enzyme that can cleave a glycerophospholipid between the carbonyl carbon and the oxygen at position #1 of the molecule. | Figure 19.6 | Phospholipase D | An enzyme that can cleave a glycerophospholipid between the phosphate and the oxygen nearest the acyl group on carbon #3 of the molecule. | Figure 19.6 | Choline kinase | Choline + ATP <=> Phosphocholine + ADP | Figure 19.5 | CTP:phosphocholine cytidylyltransFerase | Phosphocholine + CTP <=> CDP-choline + PPi | Figure 19.5 | CDP-choline:1,2-diacylglycerol choline phosphotransFerase | CDP-choline + Diacylglycerol <=> CMP + Phosphatidylcholine | Figure 19.5 | Phosphatidylserine decarboxylase | Phosphatidylserine + H+ <=> Phosphtidylethanolamine + CO 2 |  | Phosphatidylethanolamine serinetransFerase | Phosphatidylserine + Ethanolamine <=> Phosphatidylethanolamine + Serine |  | phospholipase A2 | An enzyme that can cleave a glycerophospholipid between the carbonyl carbon and the oxygen at position #2 of the molecule. Action of this enzyme on phosphatidylcholine yields lysolecithin. The enzyme may also be involved in removal of fatty acid hydroperoxides. | Figure 19.6 | Phospholipase C | An enzyme that can cleave a glycerophospholipid between the phosphate and the oxygen nearest carbon #3 of the molecule. | Figure 19.6 | Phosphatidylinositol Synthase | CDP-diacylglycerol + myo-Inositol <=> Phosphatidylinositol + CMP | Figure 19.8

Category - General

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

Reversal - there is no reversal

(Questions on left, answers in middle, figures on right)

What are the names of the most abundant prostaglandins and thromboxane? | PGG2, PGH2, PGE2, PGD2, PGI2, PGF 2, 6-keto-PGF 1, TxA2 (thromboxane). |  | What is a triterpene found as a linear molecule in cholesterol biosynthesis? | Squalene | Figure 19.28

What are three lipid modifications of proteins? | 1. Anchoring of glycoproteins by a glycosylated form of phosphatidylinositol of Trypanosoma brucei. |  | 2. transFer of single, saturated acyl groups to form an amide with glycine (N-terminus) or a thioester with cysteine. |  | 3. Isoprenylation - transFer of C15 or C20 groups from intermediates in cholesterol synthesis to cysteine residues four positions from the C-terminus. The modification removes the terminal three groups, leaving the isoprenyl group at the new C-terminus. |  | What are the sugar nucleotides involved in glycosphingolipid biosynthesis? | UDP-glucose | Figure 19.14 | UDP-galactose |  | UDP-N-acetylgalactosamine |  | CMP-sialic acid |  | What are the two five-carbon molecules used to build the isoprenoids? | Isopentenyl pyrophosphate |  | Dimethylallyl pyrophosphate |  | What is the sequence of events in photoreception in rod cells? | 1. Binding of 11-cis-retinal by opsin to form rhodopsin |  | 2. Isomerization of the retinal component of opsin to the all-trans form to create bathorhodopsin. |  | 3. Loss of a proton by bathorhodopsin to create metarhodopsin II. Activation of transducin to initiate the visual cascade. |  | 4. Release of all-trans-retinal from metarhodopsin II to re-form opsin. |  | 5. Isomerization of all-trans-retinal to 11-cis-retinal by retinal isomerase. |  | What hydroxylations happen to 25-hydroxycholecalciferol when calcium levels are low? | Low - Carbon #1 is hydroxylated to form 1,25-dihydroxycholecalciferol, which is the active form of vitamin D |  | What hydroxylations happen to 25-hydroxycholecalciferol when calcium levels are high? | High - Carbon #24 is hydroxylated to form 24,25-dihydroxycholecalciferol, an inactive form of the vitamin. |  | What are the three steps in prostaglandin synthesis? | 1. Release of arachidonic acid from membrane phospholipids. |  | 2. Oxygenation of arachidonate to yield PGH2, a prostaglandin endoperoxide that serves as precursor to other prostaglandins. |  | 3. Conversion of PGH to other prostaglandins or to TxA2. PGH may be left unaltered as well. |  | What compounds help stimulate release of arachidonic acid? | Hormones, such as bradykinin |  | Epinephrine |  | Proteases, such as thrombin. |  | What are the two activities of the bifunctional enzyme, PGH synthase? | 1. A cyclooxygenase,which introduces two molecules of O 2 into arachidonic acid - one to form the ring and one to form a hydroperoxy group at C-15. | Figure 19.31 | 2. A two-electron reduction of the peroxide to give the hydroxyl group at carbon 15 of PGH2. |  | Which activity of PGH synthase is the target of non-steroidal anti-inflammatory drugs, such as aspirin or ibuprofen? | The cyclooxygenase activity |  | What are the three predominant phospholipids in bacteria? | Cardiolipin, Phosphatidylethanolamine, Phosphatidylglycerol |

How are prostaglandins named? | The major groups of prostaglandins are assigned letters in the form of PGG, PGH, etc., where PG stands for prostaglandin and the letter following is a type of prostaglandin. Carbons are numbered beginning with the carboxyl as number 1. A numerical subscript indicates the number of double bonds in the compound and the designation or indicates whether the hydroxyl at position 9 is cis to the 11-hydroxyl group () or trans (). If hydroxyls are not present at 9 and 11, no / designation is used. Thus, PGF 2 is prostaglandin F with two double bonds and the hydroxyl at position 9 cis to the 11-hydroxyl group. |  | How do mammalian organisms eliminate steroid hormones? | Via conjugation through hydroxyl groups to glucuronate or sulfate, followed by excretion in the urine. |  | How do phospholipid molecules move from one site to another within eukaryotic cells? | Largely through transFer of fragments of membranes of the endoplasmic reticulum into the Golgi complex. | Figure 19.1 | How do the eicosanoids behave like and differ from hormones in their actions? | They behave like hormones in exerting specific physiological effects on target cells. They differ from hormones in acting locally, near their sites of synthesis, and they are catabolized extremely rapidly. |  | How does platelet-activating factor bring about its effects? | Through binding to a high-affinity receptor in the membrane of receptor cells, which interact with signal transduction systems through G proteins. |  | How is the level of a steroid hormone controlled? | By its rate of synthesis, which is ultimately controlled by signals from the brain. Steroid hormones are not stored for release at a later time. |  | In what animal organ do the methylation reactions on phosphatidylethanolamine (making phosphatidylcholine) occur? | Liver |  | In what cellular organelle in animals does synthesis of phosphatidylglycerol occur? | Mitochondria |  | In what eukaryotic cellular organelle does synthesis of ether phospholipids occur? | Peroxisomes |  | Some membrane phospholipids also are metabolic precursors of what important communication system? | Signal transduction pathways. |  | What are the most abundant bile acids in humans? | Cholic acid and chenodeoxycholic acid |  | What are the most common leukotrienes? | Leukotriene A4, B4, and C4. | Figure 19.32 | What are two synthetic estrogens that inhibit pituitary secretion of hormones controlling the female reproductive cycle? | Norethynodrel and Mestranol |  | What compounds are put together in cells to make 3-ketosphinganine, a precursor of the sphingolipids? | Palmitoyl-CoA and Serine | Figure 19.13 | What do bacteria do to maintain optimal membrane fluidity, when grown at low temperature? | Increase saturation of membrane fatty acids. |  | What effect does 1,25-dihycroxycholecalciferol have on osteoblasts? | It stimulates calcium uptake for deposition as calcium phosphate, the primary material of bone. |  | What effect does 1,25-dihydroxycholecalciferol have on intestine cells? | It binds to a receptor and stimulates transcription of a protein that stimulates calcium absorption into the bloodstream. |  | What effects does platelet-activating factor have on the body? | Stimulation of blood platelet aggregation, reduction of blood pressure, activation of several white blood cell classes, decreased cardiac output, stimulation of glycogenolysis, and stimulation of uterine contraction. |  | What enzyme is the most important one in regulating cholesterol biosynthesis? | HMG-CoA reductase |  | What glycerolipid, common in spirochetes, is the principal antigenic component in the Wasserman test, formerly used for diagnosis of syphilis? | Cardiolipin |  | What is required for activation of steroid hormone synthesis? | Stimulation of both hydrolysis of cholesterol esters and uptake of cholesterol into mitochondria of cells in the target organ. |  | What is the common name of the unusual ether lipid, 1-alkyl-2-acetylglycerophosphocholine? | Platelet-activating factor |  | What is the most common arrangement of fatty acids in glycerophospholipids? | Saturated fatty acid at carbon number 1 of glycerol and unsaturated fatty acid at carbon number 2. |  | What is the name of the most physiologically potent compound known? | Platelet-activating factor |  | What is the reaction that creates S-Adenosylmethionine? | Methionine + ATP <=> S-Adenosylmethionine + PPPi |  | What moiety in certain gangliosides is recognized by influenza virus? | Sialic acid |  | What molecule is a product of the reaction that is the committed step in cholesterol biosynthesis? | Mevalonate |  | What other enzyme besides HMG-CoA reductase can also act on 3-hydroxy-3-methylglutaryl-CoA? | HMG-CoA Lyase |  | What percentage of the total lipid of human myelin do sphingolipids constitute? | 25% |  | What phosphatidyl derivative is implicated in anchoring of proteins in the membranes of the protozoan Trypanosoma brucei? | A glycosylated form of phosphatidylinositol. | Figure 19.9 | What two mechanisms are used to regulate the activity of HMG-CoA Reductase? | Its synthesis is inhibited transcriptionally by cholesterol (or a hydroxylated derivative) and the activity of the enzyme is controlled by cyclic phosphorylation and dephosphorylation. |  | What unusual lipids are abundant in the membranes of halophilic microorganisms? | Ether-containing lipids. |  | Where in eukaryotic cells does biosynthesis of prostaglandins occur? | Endoplasmic reticulum |  | Where in the cell are phostidylglycerol and cardiolipin primarily found and synthesized? | Mitochondria |  | Which class of eicosanoids is synthesized in a pathway separate from that of prostaglandins or thromboxanes? | Leukotrienes |  | Which class of steroid hormones is the precursor of all other steroid hormones? | The protestins. | Figure 19.24 | Which ganglioside is bound by cholera toxin? | Ganglioside GM1 |  | Which hormone is involved in stimulating synthesis of the mineralocorticoids and glucocorticoids? | Adrenocorticotropic Hormone (ACTH) |  | Which phospholipases are implicated in release of arachidonate in the cell? | Phospholipase A2 and Phospholipase C |  | Which prostaglandin has been reported to elevate levels of cGMP in target cells? | PGF 2. |  | Which prostaglandin inhibits platelet aggregation and relaxes coronary arteries? | PGI2 |  | Which prostaglandin inhibits progesterone secretion and regression of the corpus luteum? | PGF 2 |  | Which prostaglandin is a vasodilator? | PGE1 |  | Which prostaglandin is used to induce labor in mothers due to its effects in stimulating uterine contraction? | PGF 2 |  | Which prostaglandin is used to reduce the risk of blood clotting during cardiopulmonary bypass operations? | PGI2 |  | Which prostaglandin stimulates adenylate cyclase in some cells? | PGE |  | Which prostaglandins are used to induce abortion in the second trimester or to induce delivery of a dead fetus? | PGF 2 and PGE2 |  | Which thromboxane counteracts the effects of PGI2? | TxA2 |  | Why do HMG-CoA lyase and HMG-CoA reductase, which can both act on 3-hydroxy-3-methylglutaryl-CoA not compete directly with each other? | HMG-CoA lyase is located in the mitochondrial matrix, apart from the endoplasmic reticulum, where isoprenoid biosynthesis (involving HMG-CoA reductase) occurs. |  | What are the 4 steps in intracellular synthesis and transport of phospholipids? | 1. Phospholipids are synthesized in the smooth endoplasmic reticulum. | Figure 19.1 | 2. transport vesicles pinch off from the smooth endoplasmic reticulum and become absorbed into the Golgi complex, carrying the phospholipids with them. |  | 3. Secretory vesicles deliver materials to the outside of the cell. |  | 4. Other transport vesicles carry phospholipids and other membrane components to specific sites within the cell, including the plasma membrane. |  | What are the six classes of glycerophospholipids found in eukaryotic cells? | 1. Phosphatidylethanolamine |  | 2. Phosphatidylglycerol |  | 3. Cardiolipin |  | 4. Phosphatidylserine |  | 5. Phosphatidylcholine |  | 6. Phosphatidylinositol |  | What are the three routes to synthesis of phosphatidic acid in eukaryotes? | 1. Starting with glycerol-3-phosphate, followed by two acylations. |  | 2. Starting with dihydroxyacetone phosphate, followed by an acylation, a reduction, and then a second acylation. |  | 3. Phosphorylation of a diacylglycerol. |  | What pathway in animal cells leads to phosphatidylcholine starting with choline? | 1. Choline -> 2. Phosphocholine -> 3. CDP-choline -> 4. Phosphatidylcholine | Figure 19.5

Category - General

Query - What is the deficient enzyme in the sphingolipid catabolism disease below?

Reversal - there is no reversal

(disease on left, enzyme in middle, figure on right)

GM1 gangliosidosis | -Galactosidase |  | Tay-Sachs Disease | -N-Acetylhexosaminidase A |  | Gaucher's Disease | -Glucosidase |  | Fabry's Disease | -Galactosidase A |  | Niemann-Pick Disease | Sphingomyelinase |  | Farber's lipogranulomatosis | Ceramidase |  | Globoid Cell Leukodystrophy | -Galactosidase |  | Metachromatic leukodystrophy | Arylsulfatase A |  | Sandhoff Disease | N-Acetylhexosaminidases A and B |

Category - General

Query - What is the accumulated intermediate in the sphingolipid catabolism disease below?

Reversal - there is no reversal

(disease on left, intermediate in middle, figure on right)

GM1 gangliosidosis | GM1 ganglioside |  | Tay-Sachs Disease | GM2 (Tay-Sachs) ganglioside |  | Gaucher's Disease | Glucosylceramide |  | Fabry's Disease | Trihexosylceramide |  | Niemann-Pick Disease | Sphingomyelin |  | Farber's lipogranulomatosis | Ceramide |  | Globoid Cell Leukodystrophy | Galactosylceramide |  | Metachromatic leukodystrophy | 3-Sulfogalactosyl ceramide |  | Sandhoff Disease | GM1, ganglioside, and globoside |

Category - General

Query - What group of steroid hormones serves as an immediate precursor for the one below?

Reversal - there is no reversal

(query term on left, solution in middle, figure on right)

Mineralocorticoids | Progestins |  | Glucocorticoids | Progestins |  | Androgens | Progestins |  | Estrogens | Androgens |

Category - General

Query - How many units of dimethylallyl pyrophosphate and isopentenyl pyrophosphate are used to make the following isoprenoid intermediates?

Reversal - there is no reversal

(isoprenoid intermediate on left, solution in middle, figure on right)

Geranyl pyrophosphate | One dimethylallyl pyrophosphate and one isopentenyl pyrophosphate |  | Farnesyl pyrophosphate | One dimethylallyl pyrophosphate and two isopentenyl pyrophosphates |  | Presqualene Pyrophosphate | Two dimethylallyl pyrophosphates and four isopentenyl pyrophosphates. |  | Squalene | Two dimethylallyl pyrophosphates and four isopentenyl pyrophosphates. |