Fatty acids diagram

Fig. IV-17. A schematic phase diagram illustrating the condensed mesophases found in monolayers of fatty acids and lipids.

Figure C2.4.1. Schematic diagram of a fatty acid witir a hydrophiiic (COO ) and a hydrophobic end group (CH ) (ieft) and of an amphiphiie in generai (right).

Fig. 4. Process stream diagram for the production of fatty acids through hydrolysis of fats and oils. Steam is at 5.2—6.2 MPa (750—900 psi). To convert MPa...

It was estabhshed ia 1945 that monolayers of saturated fatty acids have quite compHcated phase diagrams (13). However, the observation of the different phases has become possible only much more recendy owiag to improvements ia experimental optical techniques such as duorescence, polarized duorescence, and Brewster angle microscopies, and x-ray methods usiag synchrotron radiation, etc. Thus, it has become well accepted that Hpid monolayer stmctures are not merely soHd, Hquid expanded, Hquid condensed, etc, but that a faidy large number of phases and mesophases exist, as a variety of phase transitions between them (14,15). 

Another interesting class of phase transitions is that of internal transitions within amphiphilic monolayers or bilayers. In particular, monolayers of amphiphiles at the air/water interface (Langmuir monolayers) have been intensively studied in the past as experimentally fairly accessible model systems [16,17]. A schematic phase diagram for long chain fatty acids, alcohols, or lipids is shown in Fig. 4. On increasing the area per molecule, one observes two distinct coexistence regions between fluid phases a transition from a highly diluted, gas -like phase into a more condensed liquid expanded phase, and a second transition into an even denser... 

Fujiwara et al. studied the precipitation phase boundary diagrams of the sodium salts of a-sulfonated myristic and palmitic acid methyl esters in the presence of calcium ions [61]. The time dependency of the precipitation showed that the calcium salts have an extremely slow crystallization rate at room temperatures. This is the reason for the good hardness tolerance of the a-sulfonated fatty acid methyl esters. 

Figure 10.2. Schematic diagram showing how restricted conversion of fatty acids to amino acids influences the fractionation between collagen and CO3 of bone apatite LI = lipid component, PR = protein, T = total isotopic composition AP = COj component of apatite, a) Herbivorous diet (Cj plants only) b) Carnivorous diet, assuming rj = 1 (no barrier to fatty acid conversion to AAs) c) Carnivorous diet, assuming ri < 1 note that carbonate-collagen fractionation is smaller.

Figure 41-5. Diagram of a section of a bilayer membrane formed from phospholipid molecules. The unsaturated fatty acid tails are kinked and lead to more spacing between the polar head groups, hence to more room for movement. This in turn results in increased membrane fluidity. (Slightly modified and reproduced, with permission, from Stryer L Biochemistry, 2nd ed. Freeman, 1981.)...

Fig. 10.5 Schematic diagrams a micelle consisting of ionized fatty acid molecules, a phospholipid bilayer and the vesicle bilayer of a liposome...

KDO appears to be unique to Gram-negative bacteria. In the LPS that have been studied, KDO residues are situated at the reducing ends of the polysaccharide domains, linking them, by ketosidic bonds, to the fatty-acid-substituted 2-amino-2-deoxy-D-glucosyl disaccharides referred to as lipid A. Fig. 2 is a block diagram indicating the location of KDO in the LPS from Salmonella. 

Figure 5.1 The structure of a glycerophospholipid. A simple diagram showing the charges on the head group. In this struction, palmitic and oleic acids, provide the hydrophobic component of the phospholipids and choline (and four bases) and the phosphate group provide the hydrophilic head. The unsaturated fatty acid, oleic acid, provides a kink in the structure and therefore some flexibility in the membrane structure which allows for fluidity. The more unsaturated the fatty acid, the larger is the kink and hence more fluidity in the membrane. Cholesterol molecules can fill the gaps left by the kink and hence reduce flexibility. Hydroxyl groups on the bases marked are those that form phosphoester links. Choline and inositol may sometimes be deficient in the diet so that they are, possibly, essential micronutrients (Chapter 15).

Figure 11.4 Condensation, dehydration and reduction reactions in fatty add synthesis. These reactions constitute the major components of the pathway of fatty acid synthesis and are all catalysed by fatty acid synthase. The reduction reactions, indicated by addition of 2H in the diagram, involve the conversion of NADPH to NADP . (The re-conversion of NADP back to NADPH occurs in the pentose phosphate pathway.) The condensation reaction results in an increase in size of acyl-ACP by two carbon units in each step. The two carbons for each extension are each provided by malonyl-CoA. ACP - acyl carrier protein.

Figure 11.7 Synthesis of triaq/lglyceroL The precursors are glycerol 3-phosphate and long-chain acyl-CoA. R, is a saturated fatty acid, R2 is an unsaturated fatty acid (one or two doubte bonds) and R3 is either saturated or unsaturated. The activity of GPAT-1 regulates triacylglycerol synthesis. In all reactions involving RCO.SCoA, the CoASH is released but is not shown in this diagram. P,- - phosphate.

Figure 20.18 The central dogma of molecular biology a summary of processes involved inflow of genetic information from DNA to protein. The diagram is a summary of the biochemical processes involved in the flow of genetic information from DNA to protein via RNA intermediates. This concept had to be revised following the discovery of the enzyme, reverse transcriptase, which catalyses information transfer from RNA to DNA (see Chapter 18). It may have to be modified in the future since changes in the fatty acid composition of phospholipids in membranes can modily the properties of proteins, and possibly their functions, independent of the genetic information within the amino acid sequence of the protein (See Chapters 7, 11 and 14).

Figure 21.21 Diagram to illustrate the intertissue triacylglycerol/ fatty acid cycle, (i) Fatty acids released from adipose tissue are esterified in the liver, (ii) The triacylglyceral is released in the form of VLDL. (iii) The triacylglycerol in the latter is hydrolysed in the capillaries in the adipose tissue. Some fatty acids are taken up by adipose b ssue, but about 30% are release in the circulation that give life to the extracellular cycle. The intracellular cycle exists in the adipocytes.

Figure 21.24 An overview of amino acid metabolism, particularly amino acid metabolism, in a patient suffering from cancer. The tumour acts as a sink for glucose, amino acids and glutamine. As tumour grows in size, the sink is exaggerated and cachexia develops. This diagram can be considered with that in Figure 21.22 in order to include fatty acids in tumour metabolism. Note the thicker line to indicate magnitude of release of glutamine by muscle.

Figure 22.6 How various factors increase the risk of atherosclerosis, thrombosis and myocardial infarction. The diagram provides suggestions as to how various factors increase the risk of development of the trio of cardiovascular problems. The factors include an excessive intake of total fat, which increases activity of clotting factors, especially factor VIII an excessive intake of saturated or trans fatty acids that change the structure of the plasma membrane of cells, such as endothelial cells, which increases the risk of platelet aggregation or susceptibility of the membrane to injury excessive intake of salt - which increases blood pressure, as does smoking and low physical activity a high intake of fat or cholesterol or a low intake of antioxidants, vitamin 6 2 and folic acid, which can lead either to direct chemical damage (e.g. oxidation) to the structure of LDL or an increase in the serum level of LDL, which also increases the risk of chemical damage to LDL. A low intake of folate and vitamin B12 also decreases metabolism of homocysteine, so that the plasma concentration increases, which can damage the endothelial membrane due to formation of thiolactone.

The manufacture of fatty acid from fat is called fat splitting (B), and the process flow diagram is shown in Fig. 3. Washouts from the storage, transfer, and pretreatment stages are the same as those for process (A). Process condensate and barometric condensate from fat splitting will be contaminated with fatty acids and glycerine streams, which are settled and skimmed to recover... 

FIGURE 7-32 Bacterial lipopolysaccharides. (a) Schematic diagram of the lipopolysaccharide of the outer membrane of Salmonella ty-phimurium. Kdo is 3-deoxy-o-manno-octulosonic acid, previously called ketodeoxyoctonic acid Hep is L-glycero-D-mannoheptose AbeOAc is abequose (a 3,6-dideoxyhexose) acetylated on one of its hydroxyls. There are six fatty acids in the lipid A portion of the molecule. Different bacterial species have subtly different lipopolysaccharide structures, but they have in common a lipid region (lipid A), a core oligosaccharide, and an "O-specific" chain, which is the prin-... 

The composition data obtained for the series of mixed fatty acid-potassium soap systems, prepared by both the ethanol and petroleum ether routes, lend strong support to the formation of 1 to 1 acid-soap complexes. It is of interest to inquire into the phase relationships in these two-component systems. A phase diagram presented by McBain and Field (15) for the lauric acid-potassium laurate system shows that compound formation takes place between the two components at the 1 to 1 molar ratio, but the compound undergoes melting with decomposition at 91.3 °C. [A similar type of phase behavior has been reported by us for the sodium alkyl sulfate-alkyl alcohol (9) and sodium alkyl sulfonate-alkyl alcohol (12) systems, but in these cases the stoichiometry is 2 to 1]. 

Fatty acid molecules can align to form a barrier called a bilipid layer, shown here. In this schematic, the ionic end of the fatty acid is shown as a circle and the nonpolar chain is shown as a squiggly line. Use this diagram for questions 93—94. 

Fig. 10. The leh-hand diagram shows an organic superlattice with a unique polar axis. The two types of molecule involved could be a fatty acid and a fatty amine. The insert is designed to show that these two materials have dipole moments in opposite senses with respect lo the hydrophobic chain. Thus, the V-lype film has a resultant dipole moment...

Recently Kenn et al. [89] have studied films of docosanoic acid and have used their results to construct a phase diagram for this material which they believe to be representative for most fatty acids. This work will be discussed in the next section. 

Figure 5.2. Tricosa-m, n-diynoic acid (a diacetylene fatty acid). This is a schematic diagram to illustrate the definition of m and n. n = m + 2.

The phase behavior of a synthetic lecithin, dipalmitoyllecithin, as analyzed by Chapman and co-workers (5), is diagrammed in Figure 3. The main features are the same as in the phase diagram of egg lecithin a mixture of numerous homologs. As a consequence of the variation in fatty acid chain length, the chain melting point is lowered which means that the critical temperature for formation of liquid crystalline phases is reduced. This temperature is about 42 °C for dipalmitoyllecithin, and, if the lamellar liquid crystal is cooled below this temperature, a so-called gel phase is formed. The hydrocarbon chains in the lipid bilayers of this phase are extended, and they can be regarded as crystalline. The gel phase and the transitions between ordered and disordered chains are considered separately. 

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