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There are many different amino acid transporters, expressed in a tissue-specific manner. Each has a fairly broad specificity and transports a number of amino acids. They are described further in Table 2. They may come in the form of non-esterified fatty acids that have been carried through the plasma bound to albumin. Alternatively, they may be liberated from triacylglycerol in the plasma carried in lipoprotein particles, to be discussed further in Chapter 10 by the enzyme lipoprotein lipase attached to the endothelial cells that line the capillaries.

They cross the endothelial cell lining and enter cells e. The gradient is maintained because the fatty acids are utilized for further metabolism within the cells. The first step in this process is always esterification to coenzyme A to form acyl-CoA thioesters. This step is sometimes called activation. Amino acids are found free i. They may be present at considerably higher concentrations inside cells than out, reflecting the presence of active transport mechanisms for their entry into cells. The best data are available for skeletal muscle since small samples can be taken from human subjects with a special needle with a cutting edge.

The sample biopsy is then frozen rapidly in liquid nitrogen to prevent further metabolism, and the amino acids are analyzed. A correction is made for the amount of amino acid present in extracellular fluid using the measurement of Cl— ions, which are present mainly in the extracellular fluid. The amino acid transporters are often referred to as systems e. Now the genes for the individual transport proteins have been cloned. There are also specific groups of transporters involved in moving amino acids across epithelial cells i.

BCAA, branched-chain amino acids. However, this is not an entirely accurate picture. Hence, there may also be a need for active transport mechanisms. There is still debate about how fatty acids cross cell membranes.


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The rate at which this could happen based on physicochemical calculations and measurements in artificial membranes seems just about sufficient to account for rates of fatty acid utilization observed. However, as mentioned above, there is increasing evidence for specific fatty acid transport proteins in the cell membrane. It is probable that fatty acids enter cells by a combination of routes, partially facilitated some of which may be active , and partly passive diffusion. Some of the putative fatty acid transporters are listed in Table 2.

In adipose tissue, fatty acids also need to leave the cell during fat mobilization. In this case the concentration gradient is reversed because lipases within the adipocyte liberate fatty acids at a high rate from stored triacylglycerol. Fatty acid transport across cell membranes is regulated on a short-term basis. This is an active field of research and new data are constantly emerging.

FATP1 also seems to be subject to regulation by insulin-stimulated translocation in adipocytes, and therefore plays a role in fatty acid upake in the fed state. Recent discoveries show this to be an oversimplification. The diet contains many plant- and fish-derived substances that are chemically very similar to cholesterol, some of which are termed sitosterols.

Thus, absorption must be very selective, and that immediately suggests a carrier mechanism. There is a rare inherited condition, sitosterolemia, in which high levels of sitosterols are found in 40 Cellular Mechanisms Involved in Metabolic Regulation Table 2. Related to the family of fatty acid binding proteins but restricted to the plasma membrane; may cooperate with other proteins in fatty acid uptake. It has been suggested that acyl-CoA synthase which esterifies fatty acids with CoA is intimately involved in the transport of fatty acids into cells.

It is associated with membranes. Metabolic Regulation Brought About by the Characteristics of Tissues 41 the plasma, and this results in atherosclerosis just as when cholesterol levels are high. In addition, a related transporter, ABC-A1, was identified through a genetic disorder of lipid metabolism to be discussed later, in Section ABC-A1 is also expressed in other tissues, where it plays a crucial role in facilitating the movement of excess cholesterol from cells onto high-density lipoprotein HDL particles Figure An unrelated protein was discovered through identification of the gene responsible for a rare disorder of lipid storage, Niemann-Pick disease type C.

It also turns out to be a cholesterol transporter. The way in which these transporters interact to bring about specific absorption of cholesterol from the intestine will be covered in Chapter 3. This would include lactate and pyrvuate, and the ketone bodies, acetoacetate and 3-hydroxybutyrate.

These molecules move by facilitated diffusion, achieved with one of a family of proteins known as monocarboxylate transporters gene family SLC Members of this family have twelve membrane-spanning domains. They are expressed in a tissue-specific manner, but little is known of their potential as regulators of metabolism. In some tissues it is clear that they are expressed in high amounts and are likely to allow equilibration of molecules across the cell membrane.

See Further Reading for more details. We should not imagine that water will cross cell membranes by diffusion. There is now known to be a family of related aquaporins, with somewhat different properties, expressed on a tissue-specific basis. These channels are abundant in cell membranes. It is not clear, however, that they play much of a role in energy metabolism. The activity of some aquaporins is regulated by translocation to the cell membrane, as described in Figure 2. Other closely related proteins the aquaglyceroporins are carriers for glycerol, a molecule with similar physicochemical properties to water.

Again they are expressed in a tissuespecific manner. The aquaglyceroporins are important in fat cell adipocyte function, since glycerol is released from the adipocyte during the process of fat mobilization Section 5. They are also important in maintaining the barrier function of the skin, showing that glycerol is an important component 42 Cellular Mechanisms Involved in Metabolic Regulation of skin function which may explain why it is a major component of most hand creams.

The precursor metabolite may activate steps in the pathway sometimes called feed-forward ; intermediates in the pathway may regulate flux through the pathway; or the product s of the pathway may suppress metabolic flux usually called product inhibition Figure 2.

We will deal with some specific examples as we meet them in this book. Many pathways are also controlled by factors external to the pathway, and here we will look at some general mechanisms involved in such control. In this section we will look particularly at how some pathways are rapidly controlled by hormones, and in later, in Chapter 4, at how nutrients and hormones can affect gene expression, and thus longer-term control of metabolic pathways.

Pathways may be controlled by hormones, secreted from endocrine glands Chapter 6 , carried through the plasma and acting on the cell where the pathway takes place the target cell. The nervous system Chapter 8 also relays signals from distant organs often the brain that can alter metabolic flux, and there are many parallels between nervous system activity and hormone action. Hormones act on target cells by binding to specific receptor proteins.

There are two major types of hormone—receptor interaction: on the cell surface peptide hormones, catecholamines and within the cell thyroid hormones, steroid hormones. All the hormones that act through intracellular receptors exert their effects on gene expression. In this chapter, we will just consider hormones acting through cell-surface receptors, since these are involved in rapid metabolic adjustments.

Most metabolic pathways occur within cells although some involve transport of substances through the cell membrane: e. Therefore, the binding of the hormone to its receptor embedded in the cell membrane must cause events to take place within the cell that alter metabolic flux. These links between hormone binding and metabolic effects are known as signal chains or signal transduction.

Boxes 2. The signal chains drawn out as examples in Box 2. One molecule of enzyme can bring about the transformation of many molecules of its substrate. There are some exceptions: insulin-like growth factors can bind to and act through the insulin receptor; the catecholamines adrenaline epinephrine and noradrenaline norepinephrine share a family of receptors.

Here we are considering only those receptors that are expressed on the cell surface. Adrenoceptors: The catecholamines — adrenaline a hormone and noradrenaline a neurotransmitter — share receptors called adrenergic receptors or adrenoceptors: there is a family of these described in Chapter 6 Table 6. The glucagon receptor is also a GPCR. There are three different types of G-proteins involved in energy metabolism: stimulatory G-proteins, Gs , that activate adenylyl cyclase; inhibitory G-proteins, Gi , that inhibit adenylyl cyclase; and Gq , G-proteins that activate phospholipase C.

In diagrams this system will only be shown very schematically e. It is formed by guanylyl cyclase from GTP: its roles include regulation of ion transport in the kidney and relaxation of smooth muscle. It is related to the protein troponin that triggers skeletal muscle contraction Box 9.

Phosphatidylinositol and related compounds: Phosphatidylinositol is a phospholipid that is associated with the inner leaflet of the cell membrane. The hydroxyl groups of the inositol ring may be phosphorylated. PIP3 plays a key role in insulin signaling Box 2. Enzymes This box briefly describes some of the enzymes common to many of the control processes discussed in this book.

Adenylyl cyclase or adenylate cyclase : This is an integral protein of the plasma membrane. It is activated or inhibited by interaction with membrane-associated G-proteins. Phospholipase C: This is also a cell membrane-bound enzyme, activated by another class of G-proteins, Gq. Phosphatidylinositolkinase PI3K, Figure 2. The following are serine or threonine kinases, involved in regulation of enzyme activity.

In its inactive state it is composed of four subunits — two regulatory R subunits and two catalytic C subunits. When cAMP binds to the R subunits, they dissociate, leaving the catalytic subunits active against protein targets. These activators include diacylglycerol and PIP3. It is now recognized to play a role in several signal chains relevant to energy metabolism although it has retained its original name Box 2. Mitogen-activated protein kinases MAPKs are central to a family of signal chains that link cell-surface receptors, especially those for growth factors including insulin-like growth factors 1 and 2 IGF-1 and IGF-2 , with altered gene transcription in the nucleus, altered post-translational processing of proteins and control of the cell cycle.

For more details of regulation of metabolism via control of gene expression, see Chapter 4. These MAPK pathways are sometimes described as cascades, and each consists of a chain of phosphorylation events. For more detail see Shaul and Seger in Further Reading. This activates it, and it phosphorylates and activates among other proteins PKB. Protein Phosphatases There is a large family of protein phosphatases involved in dephosphorylation of serine, threonine, and tyrosine residues and, hence, regulation of enzyme activity.

Protein phosphatase-1 PP-1 is a serine phosphatase that plays a particular role in energy metabolism. PP-1 may have a subunit that associates it with glycogen, the glycogen targeting subunit. PP-1 that is associated with glycogen is known as PP-1G. There are glycogen targeting subunits that are specific to liver and muscle, called in the literature GL and GM respectively.

Metabolic Regulation: A Human Perspective

The activity of PP-1 is itself regulated: for instance, it is activated by insulin, leading to dephosphorylation and hence inactivation of glycogen synthase. For many dephosphorylation reactions, however, it seems that the phosphatase activity is constitutively expressed i. An example is the suppression of hormone-sensitive lipase HSL activity in the adipocyte by insulin. Insulin reduces phosphorylation of HSL by reducing cAMP concentration and hence PKA activity; the enzyme is dephosphorylated and inactivated by protein phosphatases that are always active.

Protein-tyrosine phosphatases are also important in metabolic regulation. One particular isoform, PTP1B, is responsible for dephosphorylation of tyrosine residues in the insulin receptor, and therefore turning off insulin action. PTP1B is itself regulated by phosphorylation. Insulin, via the insulin receptor tyrosine kinase, phosphorylates tyrosine residues in PTP1B and reduces its activity.

Signaling from catecholamines can then be seen to reduce insulin signaling. In general, tyrosine phosphorylation is involved in receptor function and early in signal chains. When enzymes are regulated by phosphorylation, it mostly involves serine residues. Sometimes the enzymatic activity is intrinsic to a protein with another function: for instance, the insulin receptor has tyrosine kinase activity, which is activated when insulin binds.

Both the kinases and the phosphatases may themselves be regulated, in some cases also by phosphorylation and dephosphorylation. Insulin binds to its receptor in the cell membrane leading to auto-phosphorylation of tyrosine residues in the receptor protein. This leads to interaction with a family of proteins known as insulin receptor substrates IRSs , which themselves become phosphorylated and then interact with the enzyme phosphatidylinositolkinase PI3K on figure.

Activated PKB leads to several cellular responses to insulin including inhibition of lipolysis Figure 2. Inactivation of GSK3 also leads to multiple cellular effects including stimulation of glycogen synthesis discussed later; Box 5. Although it seems odd to speak of inactivation of an enzyme leading to downstream events, these are brought about by specific phosphatases that are then free to dephosphorylate the proteins involved.

These interact with stimulatory G-proteins Gs that bind GTP, and which in turn interact with and stimulate adenylyl cyclase. This in turn phosphorylates and activates phosphorylase kinase in its inactive, dephosphorylated form known as phosphorylase kinase b; in its active, phosphorylated form known as phosphorylase kinase a.

Phosphorylase kinase a in turn phosphorylates and activates glycogen phosphorylase again, in its inactive, dephosphorylated form known as phosphorylase b; in its active, phosphorylated form known as phosphorylase a. Hormonesensitive lipase HSL is one of the enzymes responsible for regulation of breakdown of triacylglycerol TAG stored in adipocytes, to deliver fatty acids to the plasma. A constitutively active MAG lipase removes the final fatty acid. HSL is dephosphorylated and inactivated by constitutively active protein phosphatases.

Insulin acts through the signal chain shown in Figure 2. Acta, , — Smith, T. Johnson, L. Magnuson, M. Sugden, M. Zhou, Z. USA, 98, — Membrane Transporters Overview Hediger, M. Pflugers Arch. Krishnamurthy, H. MCTs Halestrap, A. Morris, M. AAPS J. Poole, R. Amino Acids Broer, S. Broer, S. Physiology, , 95— Hyde, R. Further Reading 51 Kanai, Y. Mackenzie, B.

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Verrey, F. Glucose Cheeseman, C. Douard, V. Holloszy, J. Schmidt, S. Schurmann, A. Simpson, I. Manolescu, A. Physiology, 22, — Pascual, J. Uldry, M. Wright, E. Wood, S. Watkins, P. Aquaporins and Aquaglycerporins Agre, P. Hara-Chikuma, M. Cell Mol. Life Sci.

Cellular Signalling, 18, — Di Paoli, G. Nature, , Eyster, K. Fredholm, B. Acta Physiol. Hardie, D. Hirsch, E. Lefkowitz, R. Long, Y. Rosenbaum, D. Schmitz-Peiffer, C. Diabetes, 57, — Schwartz, T. Shaul, Y. Strosberg, A. Taniguchi, C. Cell Biol. In the case of dietary fat, most is in the form of triacylglycerols.

These are moved through the intestinal tract, undergoing mechanical disruption and enzymatic hydrolysis, largely to liberate their constituent simpler molecules, sugars, amino acids, and fatty acids. Fats are also emulsified with the bile salts as emulsifiers. The last stages of breakdown of carbohydrates are brought about by enzymes associated with the microvillus membranes brush border enzymes. Di- and tri-peptides can also be absorbed, as can monoacylglycerols.

Sugars and amino acids enter the hepatic portal vein and are transported to the liver. Fatty acids and monoacylglycerols are combined to make new triacylglycerols within the enterocytes, then packaged with a specific protein apolipoprotein B , phospholipids, and cholesterol to make the macromolecular aggregates called lipoprotein particles, in this case specifically chylomicrons. These enter the bloodstream via the lymphatic system, by-passing the liver. All the process, especially the motility of the gastrointestinal tract and the liberation of digestive juices and enzymes, are highly regulated, mostly by hormones stimulated by the presence of food in the intestine.

In a book that describes the events connecting the eating of food and the utilization of nutrients within the body, it is necessary to look at the processes that come between food entering the mouth and its components appearing in the bloodstream. These are the processes of digestion and intestinal absorption.

The aim of this chapter is to show the relationships between food and the substrates whose metabolism will be considered in later chapters. In addition, the process of digestion illustrates some interesting examples of integration by hormones and by the nervous system. The general layout of the digestive tract is shown in Figure 3. We shall deal here only with the macronutrients. Vitamins and minerals are also taken in with the diet, of course, but their handling is outside the scope of this book.

The Strategy of Digestion 55 Table 3. Not shown is a very variable amount of non-digestible carbohydrate fiber , typically 10—20 g per day. In most real meals as opposed to the pure glucose loads studied in many experimental situations there is a mixture of simple sugars, oligosaccharides, and complex carbohydrates. Of the complex carbohydrates, some will be readily digestible starch, composed of the straight-chain amylose and the branching amylopectin, together with very small amounts of glycogen in animal tissues. There are other types of starch which are resistant to digestion in the small intestine but fully digested in the large intestine; they are referred to as resistant starch.

Their chemical structure is identical to more easily digestible starch, but the polysaccharide chains are in a semicrystalline state that makes the bonds inaccessible to the usual enzymes of starch digestion. The remaining, less digestible, carbohydrate is referred to as non-starch polysaccharide or more generally as dietary fiber. The digestible carbohydrates are, for the most part, absorbed from the small intestine in the form of monosaccharides.

The strategy of the digestive process, then, is to have them in that form as they reach the small intestine. Digestion of dietary carbohydrate to monosaccharide units takes place in two stages: luminal digestion — digestion occurring in the intestinal lumen — and membrane digestion, the hydrolysis of certain small oligosaccharides by enzymes forming part of the microvillus membrane, the absorptive surface of the cells lining the small intestine.

Fat-soluble vitamins are ingested with other foods. Some are taken in as relatively water-soluble precursors, or provitamins, such as carotene in carrots and other vegetables. Others, such as vitamin D, are taken in with fatty foods and absorbed with the fat. The digestion and absorption of fat necessitates that the fat is made accessible to the enzymes which break it down for digestion. This is achieved by emulsification — formation of microscopic droplets in which the ratio of surface area where enzymes can act to mass is very large.

Thus, in considering the digestion and absorption of fat, we are concerned both with physicochemical changes and with enzymatic processes. For the most part, this makes little difference to its handling in the digestive process; proteins are hydrolyzed to free amino acids and dipeptides for absorption. Cephalic stimulation of the flow of saliva occurs through activation of the parasympathetic nervous supply to the salivary glands. The parasympathetic nervous system will be discussed in detail in Section 8. Stimulation of gastric juice secretion also occurs, and there is cephalic-phase secretion of insulin, showing the control of insulin secretion by the nervous system to be discussed in more detail later; see Section 8.

The presence of food in the mouth stimulates nerve receptors both mechanically and chemically, through taste receptors, to reinforce the stimulus to saliva production. The taste receptors, expressed in specialized taste sensory cells, are mostly G-protein coupled receptors; there are also ion channels. Saliva is produced in pairs of glands which are located along the line of the jaw: the parotid, submandibular, and sublingual. It is slightly buffered by its content of bicarbonate and phosphate ions, and contains a number of enzymes as well as the glycoprotein mucin, which gives it its lubricating properties.

This is probably not extensive unless the food is chewed for an abnormal length of time before swallowing. The most important process occurring in the mouth is mechanical breakdown of the food and its hydration with saliva. Stages of Digestion 3. The stomach is a distensible muscular sac, about 25 cm long, with a volume of around 50 ml when empty, but which can expand to hold up to 1. Interspersed with these cells are many millions of small holes, visible microscopically; these are the openings of the gastric pits or gastric glands.

The gastric pits are lined with further epithelial, mucus-secreting cells but also contain specialized cells secreting different substances: the parietal or oxyntic cells secreting HCl hydrochloric acid , and the chief cells, also known as zymogenic or peptic cells, which secrete proteins, particularly the pro-enzyme pepsinogen. The oxyntic cells also secrete the glycoprotein known as intrinsic factor, which is necessary for absorption of vitamin B The control of acid secretion is summarized in Figure 3. Secretion of HCl is stimulated by three factors acting at specific receptors on the basolateral membrane i.

Maximal acid production is only achieved when all three signals are present; any one of the three will only give weak stimulation of acid production. Cellular signaling is achieved by elevation of cAMP concentrations, which brings about translocation of the proton pump enzyme that secretes acid to the apical that is, facing into the stomach cell membrane.

Histamine is released from cells in the stomach wall in response to food in the stomach. It acts locally, on nearby cells; it is thus not a true hormone, but acts in a paracrine manner. It acts at specific receptors, known as H2 receptors, on the parietal cells; drugs which block binding at these receptors, the H2 antagonists e. The parasympathetic nervous system is activated during digestion, as noted earlier, by the taste, smell, and sight of food; when food enters the stomach, distension of its walls activates stretch receptors which send signals to the brain, which in turn causes further activation of the parasympathetic nervous system the vagus nerve , and enhances acid secretion.

A traditional surgical treatment for gastric ulcers now out of 58 Digestion and Intestinal Absorption Brain Sight. Plus signs indicate stimulation or activation; a negative sign indicates inhibition. The gastric and pyloric glands within the dotted boxes are greatly enlarged relative to the rest of the drawing. Stages of Digestion 59 fashion was to sever the vagus nerve, thus removing one stimulus for acid secretion.

When we consider later other effects of the vagus nerve e. In more recent years, highly selective vagotomy was introduced, in which only those branches innervating the stomach were cut, but even this treatment has now been superseded by the use of H2 antagonists. Gastrin, the third regulator of acid secretion, is a amino acid peptide produced by enteroendocrine cells, a general term for cells in the gastrointestinal tract that secrete hormones.

The cells that secrete gastrin are known as G cells. They are found in gastric pits in the antrum of the stomach, the region near the pylorus, the exit from the stomach that leads to the first part of the small intestine the duodenum. Gastrin is a true hormone; it is released from these cells into the bloodstream and circulates in the bloodstream.

There is no apparent short cut for it, although the cells it affects are near to the cells secreting it. The release of gastrin is stimulated by a number of factors arising from the food in the stomach: some amino acids and peptides released from partially digested protein in the stomach, caffeine, calcium, and alcohol. In addition, stimulation of gastrin secretion is reinforced by the parasympathetic nervous system, activated during the digestive process.

Gastrin acts directly on the parietal cells to stimulate acid secretion. It also has other actions in the small intestine, which will be considered below. The secretion of gastrin is inhibited by too high an acidity in the stomach; when the pH falls below about 2 the optimum for the action of pepsin gastrin secretion declines.

This seems to be brought about by release from adjacent cells of the amino acid peptide somatostatin. Somatostatin is a widespread inhibitor of peptide hormone secretion: it is found throughout the intestine, in the brain and in the pancreas, and, when given intravenously, will inhibit the secretion of many peptide hormones, including growth hormone, gastrin, insulin, and glucagon.

Its name comes from the inhibition of growth hormone, or somatotropin, secretion. Clearly, it could have very non-specific effects if released in sufficient quantities into the circulation, and somatostatin appears, like histamine, to act locally on adjacent or nearby cells; it is a paracrine regulator of hormone secretion. Excess acidity appears to act directly to stimulate somatostatin secretion and thus inhibit gastrin release.

The inhibition of gastrin release by excess acidity is a good example of feedback inhibition brought about by a hormonal regulator. The system maintains a relatively constant, and optimum, hydrogen ion concentration for digestion. The acidity of the stomach also has an antibacterial action.

But specific digestive activity also takes place here. The acidic environment in the stomach stops the action of the salivary amylase. Nevertheless, the contractile activity of the stomach is greatest near the pylorus, and after a large meal boluses of food which arrive from the esophagus may remain relatively undisturbed, and salivary amylase continues to act for up to an hour in the upper part of the stomach. A triacylglycerol lipase is secreted from glands in the stomach gastric lipase. This is an acid lipase with a pH optimum of around 4—6, although it is still active even at a pH of 1.

In other mammals a homologous lipase may be secreted higher up the gastrointestinal tract, for example, from the serous glands of the tongue in rodents lingual lipase. The realization that humans secrete a gastric lipase is relatively recent, and there are still references to human lingual lipase in the literature. Most proteins are denatured that is, their quaternary, tertiary, and secondary structures are lost in an acidic environment. This makes the peptide chains more accessible to proteolytic enzymes, which break the peptide bonds linking the amino acids.

The proteolytic enzyme produced by the chief or zymogenic cells is pepsin. This is released, as with all extracellular proteolytic enzymes, as an inactive precursor, pepsinogen. It is activated by hydrolysis, catalyzed by hydrogen ions, of a single peptide bond, releasing a 42amino acid peptide and the active enzyme. Pepsin has a very acidic pH optimum, around 2. It acts preferentially on peptide bonds in the middle of peptide chains i. Thus, proteins are broken down into shorter chains. Little absorption into the bloodstream occurs from the stomach: ethanol and some lipid-soluble drugs are absorbed, but not the normal dietary constituents.

The stomach is primarily an organ of mechanical digestion, comparable to a food liquidizer. By the rhythmic contractions of the lower part of the stomach, the food is pounded into a creamy mixture known as chyme. Entry to the duodenum is regulated by a circular muscle, the pyloric sphincter.

It opens at regular intervals about twice each minute and about 3 ml of chyme is squirted into the duodenum. The pyloric sphincter only opens partially, so that large particles are retained for further pummeling. Thus, a creamy acidic mixture of lightly digested starch, partially digested protein, and coarsely emulsified fat enters the duodenum. Not in United States? Choose your country's store to see books available for purchase.

The important Third Edition of this successful book conveys a modern and integrated picture of metabolism and metabolic regulation. Explaining difficult concepts with unequalled clarity, author Keith Frayn provides the reader with an essential guide to the subject. Covering topics such as energy balance, body weight regulation and how the body copes with extreme situations, this book illustrates how metabolic regulation allows the human body to adapt to many different conditions.

Changes throughout the new edition include:. Frayn has written a book which will continue to be an extremely valuable tool for scientists, practitioners and students working and studying across a broad range of allied health sciences including medicine, biochemistry, nutrition, dietetics, sports science and nursing. The Healing Nutrients Within. Richard Smayda. Harpers Illustrated Biochemistry 30th Edition. Victor W. Rapid Review Biochemistry. John W. Fighting Cancer with Vitamins and Antioxidants. Kedar N. Biochemistry Primer for Exercise Science. Peter M. Mitochondria and the Future of Medicine.

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Biochemistry for Sport and Exercise Metabolism. Donald MacLaren. Larry R. Biochemistry Dictionary for Health Professionals. Graham Shaw. Beyond the Magic Bullet. Raymond Chang. Fundamentals of Biochemistry for Medical Students. Ambika Shanmugam. Richard G.

Metabolic regulation: A human perspective

Nutritional Biochemistry. Tom Brody. Medical Biochemistry. Miriam D. Medical Biochemistry at a Glance. Medical Biochemistry - An Illustrated Review. Sankhavaram R. Outside the Box Cancer Therapies. Mark Stengler. Functional Biochemistry in Health and Disease. Eric Newsholme. Nutrient Metabolism. Martin Kohlmeier. Principles of Human Nutrition. Martin Eastwood. Eunice Li-Chan. Metabolism of carbohydrates. Nutrition and Biochemistry for Nurses - E-Book. Venkatraman Shreemathy. Lipid Biochemistry. By: Keith N Frayn Author. Publisher: Wiley-Blackwell.

Click to have a closer look. Select version. About this book Contents Biography Related titles. Images Additional images. About this book Metabolic Regulation looks in detail at how molecules, cells and tissues operate collectively in human health and disease, using an approach that has become known as 'integrative physiology'.

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