By U. Arakos. East Carolina University. 2018.
She has started to Thiamine gain weight buy 30gm acticin fast delivery, and is trying a daily exercise program 30 gm acticin overnight delivery. However, she constantly feels weak Biotin Mg2 and tired. On this visit to her nutri- Ca2 tionist, they discuss the vitamin content of her diet, and its role in energy metabolism. Fe2 Phosphate Al Martini has been hospitalized for congestive heart failure (see Chapter 8) and for head injuries sustained while driving under the influence of alco- hol (Chapters 9 and 10). He completed an alcohol detoxification program, O H enrolled in a local Alcoholics Anonymous (AA) group, and began seeing a psy- •• H C ••C~SCoA chologist. During this time, his alcohol-related neurologic and cardiac manifesta- •• H tions of thiamine deficiency partially cleared. However, in spite of the support he Acetyl CoA was receiving, he began drinking excessive amounts of alcohol again while eating poorly. Three weeks later, he was readmitted with symptoms of “high output” heart Fig. Acetyl CoA donates eight electrons to the TCA cycle, which are shown in blue, and two carbons. The acetyl group is the ultimate source of the carbons in the two molecules of CO2 that In the TCA cycle, the 2-carbon acetyl group of acetyl CoA is oxidized to 2 CO2 mol- are produced, and the source of electrons in the ecules (see Fig. The function of the cycle is to conserve the energy from this oxi- one molecule of FAD(2H) and 3 molecules dation, which it accomplishes principally by transferring electrons from intermediates NADH, which have each accepted two elec- of the cycle to NAD and FAD. The eight electrons donated by the acetyl group even- trons. However, the same carbon atoms and tually end up in three molecules of NADH and one of FAD(2H) (Fig. As a con- electrons that enter from one molecule of sequence, ATP can be generated from oxidative phosphorylation when NADH and acetyl CoA do not leave as CO2, NADH, or FAD(2H) donate these electrons to O2 via the electron transport chain. As citrate progresses through the cycle to oxaloacetate, it is oxi- organic molecules to form a car- dized by four dehydrogenases (isocitrate dehydrogenase, -ketoglutarate dehydro- bon–carbon bond. Dehydrogenases, such as genase, succinate dehydrogenase, and malate dehydrogenase), which transfer elec- isocitrate dehydrogenase, are enzymes that trons to NAD or FAD.
A Superior The cortex is arranged in folds forming elevated portions known as gyri (JI-ri) buy acticin 30gm otc, singular gyrus cheap 30 gm acticin with mastercard. These raised Anterior horn Lateral ventricles areas are separated by shallow grooves called sulci (SUL-si), singular sulcus (Fig. Although there are many sulci, the following two are especially Interventricular Posterior horns important landmarks: foramen ◗ The central sulcus, which lies be- Third Cerebral tween the frontal and parietal lobes ventricle aqueduct of each hemisphere at right angles to Lateral horn Fourth the longitudinal fissure (see Figs. The white Lateral ventricles matter consists of myelinated fibers that connect the cortical areas with each Third other and with other parts of the nerv- ventricle ous system. Cerebral Basal nuclei, also called basal gan- aqueduct glia, are masses of gray matter located deep within each cerebral hemisphere. Fourth These groups of neurons work with the ventricle cerebral cortex to regulate body move- ment and the muscles of facial expres- Cerebellum sion. The neurons of the basal nuclei secrete the neurotransmitter dopamine (DO-pah-mene). The corpus callosum (kah-LO- C Posterior sum) is an important band of white matter located at the bottom of the longitudinal fissure (see Fig. ZOOMING IN This band is a bridge between the right Which are the largest ventricles? THE NERVOUS SYSTEM: THE BRAIN AND CRANIAL NERVES 207 Box 10-1 A Closer Look The Blood-Brain Barrier: Access DeniedThe Blood-Brain Barrier: Access Denied eurons in the central nervous system (CNS) function The blood-brain barrier excludes pathogens, although some Nproperly only if the composition of the extracellular fluid viruses, including poliovirus and herpesvirus, can bypass it by bathing them is carefully regulated. The semipermeable traveling along peripheral nerves into the CNS. Some strepto- blood-brain barrier helps maintain this stable environment by cocci also can breach the tight junctions. Disease processes, allowing some substances to cross it while blocking others.
De Michele G cheap 30gm acticin, Filla A buy acticin 30 gm cheap, Volpe G, De Marco V, Gogliettino A, Ambrosio G, Marconi R, Castellano AE, Campanella G. Environmental and genetic risk factors in Parkinson’s disease: a case-control study in southern Italy. Increased risk of Parkinson’s disease in parents and siblings of patients. Plante-Bordeneuve V, Taussig D, Thomas F, Ziegler M, Said G. A clinical and genetic study of familial cases of Parkinson’s disease. Marder K, Tang MX, Mejia H, Alfaro B, Cote L, Louis E, Groves J, Mayeux R. Risk of Parkinson’s disease among first-degree relatives: a community- based study. Rybicki BA, Johnson CC, Peterson EL, Kortsha GX, Gorell JM. A family history of Parkinson’s disease (PD) and its effect on other PD risk factors. Tanner CM, Ottman R, Goldman SM, Ellenberg J, Chan P, Mayeux R, Langston JW. De Rijk MC, Breteler MMB, Graveland GA, Ott A, Grobbee DE, van der Meche FGA, Hofman A. Prevalence of Parkinson’s disease in the elderly: The Rotterdam Study. Mayeux R, Marder K, Cote LJ, Denaro J, Hemenegildo N, Mejia H, Tang M- X, Lantingua R, Wilder D, Gurland B, Hauser A. The frequency of idiopathic Copyright 2003 by Marcel Dekker, Inc. Parkinson’s disease by age, ethnic group, and sex in northern Manhattan, 1988–1993. Fall P-A, Axelson O, Fredriksson M, Hanson G, Lindvall B, Olsson J-E, Granerus A-K.
Conversion of Glucose to Cytosolic Acetyl CoA OAA Acetyl CoA OAA Acetyl CoA The pathway for the synthesis of cytosolic acetyl CoA from glucose begins with gly- citrate lyase colysis cheap acticin 30gm line, which converts glucose to pyruvate in the cytosol (Fig discount acticin 30gm overnight delivery. Pyruvate enters Citrate Citrate mitochondria, where it is converted to acetyl CoA by pyruvate dehydrogenase and to oxaloacetate by pyruvate carboxylase. Conversion of glucose to cytosolic the acetyl CoA levels in the mitochondria. As oxaloacetate levels increase because of the activity of pyruvate carboxylase, oxaloac- etate condenses with acetyl CoA to form citrate. This condensation reduces the acetyl CoA levels, which leads to the activation of pyruvate dehydrogenase and inhi- bition of pyruvate carboxylase. Through such reciprocal regulation, citrate can be continuously synthesized and transported across the inner mitochondrial membrane. In the cytosol, citrate is cleaved by citrate lyase to re-form acetyl CoA and oxaloac- etate. This circuitous route is required because pyruvate dehydrogenase, the enzyme that converts pyruvate to acetyl CoA, is found only in mitochondria and because acetyl CoA cannot directly cross the mitochondrial membrane. The NADPH required for fatty acid synthesis is generated by the pentose phos- phate pathway (see Chapter 29) and from recycling of the oxaloacetate produced by citrate lyase (Fig. Oxaloacetate is converted back to pyruvate in two steps: the reduction of oxaloacetate to malate by NAD -dependent malate dehydrogenase and the oxidative decarboxylation of malate to pyruvate by an NADP+-dependent malate dehydrogenase (malic enzyme) (Fig. The pyruvate formed by malic enzyme is reconverted to citrate. The NADPH that is generated by malic enzyme, along with the NADPH generated by glucose 6-phosphate and gluconate 6-phos- phate dehydrogenases in the pentose phosphate pathway, is used for the reduction reactions that occur on the fatty acid synthase complex (Fig. The generation of cytosolic acetyl CoA from pyruvate is stimulated by elevation of the insulin/glucagon ratio after a carbohydrate meal. Insulin activates pyruvate dehydrogenase by stimulating the phosphatase that dephosphorylates the enzyme to Glucose CO2 NADPH NADP+ Pyruvate malic enzyme Malate – COO NAD+ + Pyruvate cytosolic NADP CO2 NADPH malate CH2 CH3 dehydrogenase NADH H OH C O malic enzyme OAA Acetyl CoA citrate OAA Acetyl CoA – – COO COO lyase Malate Pyruvate ADP + Pi Citrate Citrate ATP Fig. Citrate lyase is also called citrate cleavage enzyme. NADPH is produced by the pentose phosphate pathway and by malic enzyme. The synthesis of malic enzyme, glucose 6-phosphate acetyl CoA ADP + P carboxylase i dehydrogenase, and citrate lyase is induced by the high insulin/glucagon ratio.
