Where are lipids located in the cell. Fatty acids are components of lipids. Prostaglandins are involved in the inflammatory process, enhancing it in the focus of inflammation. Prostaglandin formation inhibitors are acetylsalicylic acid and other salicylates. Aspir

On the surfaces of plant leaves and the body of some insects, beeswax and even one inside the human ear, there are other examples of this type of highly soluble lipid that prevents water loss through perspiration. They are composed of an alcohol molecule and 1 or more fatty acids.

They are the main components of cell membranes, it is a glyceride in combination with phosphate. They can have 1 to 3 fatty acids attached to a glycerol molecule. The best-known example is triglyceride, which is made up of three fatty acid molecules.

Representation of the molecular structure of cholesterol and triglycerides. They consist of 4 interconnected carbon rings connected to hydroxyl, oxygen and carbon chains. Examples of steroids are male and female sex hormones, among other hormones and cholesterol.

Lipids are an important energy reservoir that is used in times of need and is present in animals and plants. Animal fat cells form a layer that acts as a thermal insulation, essential for animals that live in cold climates.

Vegetable oils extracted from seeds such as soybean, sunflower, rapeseed and corn contain essential fatty acids that are used in the synthesis of organic molecules and cell membranes. Since these molecules are not produced in the human body, it is important to consume these oils through food. Lipids are esters, meaning they are made up of one molecule of acid and one of alcohol.

They are insoluble in water because their molecules are non-polar, meaning they have no electrical charge and therefore have no affinity for polar water molecules. Foreword This booklet has been designed to assist the student in continuing with the discipline of biochemistry introduced in the third period of the technology course in chemical processes, considering the basic concepts of carbohydrates, proteins and lipids, which are biomolecules of energy metabolism. This pamphlet is not a substitute for the study of recommended basic bibliographies, library book searches, and subsequent publication of the latest articles available on the Internet, and continuing education courses for those who intend to follow in this area. The elements that are usually involved in the composition of the molecules of such substances are: carbon, hydrogen and, ultimately, sulfur and phosphorus. Most of the molecules involved in biological processes are larger and more complex than those studied in general chemistry. The interactions between these biomolecules are also more complex, but the physical and chemical properties of these substances depend significantly on their molecular structure. Therefore, the entire study "Biochemistry" is based on the basic knowledge of general and organic chemistry, such as the identification of clusters. Biochemistry is what its name indicates the chemistry of life - a branch of science that combines chemistry - the study of the structures and interactions between atoms and molecules, and biology - the study of the structures and interactions of living cells and organisms. The chemistry of living organisms is described in terms of biomolecules, their forms, biological functions and their participation in cellular processes, metabolism. Since all beings are made up of "inanimate" molecules, life at its most basic level is a biochemical phenomenon. Although at the macroscopic level, living beings are very different from each other, they show very similar similarities in their biochemistry, namely how they use to store and transfer genetic information in a series of reactions that they use to produce energy and in synthesis and degradation. constituent blocks - metabolic pathways. Thus, metabolism is a set of transformations that substances undergo in the internal environment to provide an energy organism, update their molecules, and ensure dynamic balance. Biochemistry is a unifying theme of the study of all beings and of life itself. This is a very interdisciplinary field, which has long ceased to be just the study of various chemical reactions in the cell and the development of metabolic maps. Biochemical expertise is never waterproof and has high applicability in a wide variety of fields such as medicine and medicine, pharmaceutical, food and chemical industry. Biochemistry - biomolecules 3 Table 1. Why study biochemistry: its importance and its applications Topic Content Intermediate metabolism Identification various types food components of substances and their transformation in the internal environment. Bioenergetics How the body receives, stores and uses the energy it needs to function. Homeostasis Regulation of the balance between the internal and external environment using enzymes, vitamins and hormones. Molecular biology Continuity of life. Diet Health care through the supply of essential substances, prevention and control of diseases. Laboratory tests Evidence, evaluation and interpretation of changes in metabolism through blood tests, urine tests, etc. anthropology Biochemical analysis fossil fragments and a molecular study of human evolution. Medical treatment Study of assisted insemination, paternity disputes; Analysis of fragments of a person to clarify crimes. Specific Functions Muscle contraction, conduction of nerve impulses, membrane permeability. A large group of living beings specialize in receiving energy from light and a series of chemical compounds extracted from the earth and air: they are autotrophs capable of synthesizing their own energy sources. It turns out that these compounds are synthesized in such a quantity that it is almost never fully utilized by the autotroph, which is necessary for its storage in large quantities or for its release, as is the case with oxygen. Taking advantage of this "surplus" of food, another group of living beings, the heterotrophs, specializes in obtaining the energy needed for their organic reactions by feeding on autotrophs or their waste products. There are also some molecules necessary for the functioning of living cells that are synthesized only by autotrophs, such as certain amino acids and vitamins. Autotrophs, in turn, also require raw materials obtained from heterotrophs, such as carbon dioxide and the decomposition products of their tissues. The act of obtaining substrates for the basic organic reactions that take place within the cells of living beings, in short, constitutes feeding. Biomolecules between biomolecules are fundamental to cell biology, biomolecules that do not produce energy directly have key functions in this process. Lack of food, taboos, food beliefs and reduced purchasing power are factors that lead to malnutrition. A healthy diet can be summed up in three words: variety, moderation, and balance. Food must be supplied in sufficient quantity and quality and adequate to the needs of the individual. To better understand what it means proper nutrition we need to know the difference between nutrition and nutrients. Feeding yourself: a voluntary and conscious act. Nutrients: proteins, carbohydrates, fats, vitamins and minerals. Nutrition: involuntary and unconscious action. Products are formed by macromolecules that store large amounts of energy in their chemical bonds. Basically, food-derived nutrients receive carbohydrates, lipids, and proteins, which have the primary function of providing energy at the cellular level. Other vital nutrients for life are vitamins, minerals and fiber. Water matches chemical element in greater quantities in living beings and is a solvent for other cellular chemical compounds. Therefore, it is essential for food. The calorie content of a food refers to the amount of energy stored in each gram of that food. Biochemistry - Biomolecules 5 Food classification Food can be classified different ways according to point of view. From a biochemical point of view, the best classification refers to its biological properties: Energy: Provides substrates for maintaining body temperature at the cellular level, releasing energy for biochemical reactions. These are carbohydrates, lipids and proteins. Carbohydrates are energy products , superior to them, since they are directly synthesized during the photosynthesis of autotrophs, and all living things have the enzymes necessary for their degradation. Lipids and proteins, although they have the same or higher energy capacity even carbohydrates, have different functions in the body and are absorbed after absorption of carbohydrates, which are used secondly as energy producers, despite the high caloric capacity. Lipids are the main elements of energy storage, as they are predominantly stored in adipocytes prior to metabolism in the liver. Structural: they act in the process of growth, development and repair of damaged tissues, maintaining the shape or protecting the body. These are proteins, minerals, lipids and water. Regulators: accelerate organic processes, being indispensable for humans: they are the main vitamins, amino acids and lipids, minerals and fibers. Food label! Carbohydrates are substances commonly referred to as sugars or starches. Carbohydrates are also called saccharides, carbohydrates, aesirs, carbohydrates or sugars. They range from simple sugars containing three to nine carbon atoms to highly complex polymers. Chemically, they are polyhydroxy aldehydes or polyhydroxy ketones, or substances that release these compounds by hydrolysis. Figure 1. Structure of polyhydroxyaldehyde compared to polyhydroketone. Carbohydrate oxidation is the main metabolic pathway for energy release in many non-photosynthetic cells. They are essentially fuel for the immediate use of animal tissues, and the body stores them in small amounts. They are very water soluble, hydrophilic, and storing them means holding water, which is only convenient up to a point. Otherwise, let's look at the following data: a person weighing 70 kg and an energy store equivalent to 10 kg of fat in the form of glycogen weighs 120 kg instead of 70 kg. Most of the 50kg more will be caused by moisturizing water. This is the main function of carbohydrates, while all living beings with a metabolism are adapted to the consumption of glucose as an energy substrate. That is, the structural components of cells and tissues. In addition to acting as a prosthetic group of very specialized proteins. Classification: According to size, there are three main carbohydrates, monosaccharides, oligosaccharides or polysaccharides. These are compounds that cannot be hydrolyzed into simpler forms. Ribose also appears as a constituent of some vitamins. - hexoses: have 6 carbon atoms: glucose, fructose, galactose, are simple sugars common in food products and are the most important monosaccharides from an energetic point of view. It is the main product resulting from the hydrolysis of more than complex carbohydrates in digestion and as sugar found in the bloodstream. It is oxidized in cells as an energy source and stored in the liver and muscles in the form of glycogen. Under normal conditions, the central nervous system can use glucose as its main source of energy. Because glucose does not require digestion, it can be administered endoscopically to patients who cannot eat food and are therefore immediately used by cells as an energy source. Thus, glucose is the most important monosaccharide because it is an essential form of circulating carbohydrate in the blood and the primary glycemic source of metabolic energy. Also known as levulose or fruit sugar, it is found alongside glucose and sucrose in honey and fruits. Fructose is the sweetest of the sugars. Together with glucose, it forms sucrose disaccharides. It is an optical isomer of glucose, formed in the mammary glands from glucose. To form disaccharides, trisaccharides, or even polysaccharides, monosaccharides need to be linked together. This bond is called glycosidic and is formed between two hydroxyls: one of the anomeric carbon of the monosaccharide with any other neighboring monosaccharide with the elimination of one water molecule. The three most commonly found in foods made up of at least one glucose molecule: sucrose = glucose and fructose. Lactose = glucose and galactose. It is found mainly in sugar cane, beet sugar, molasses and corn syrup, as well as in fruits, vegetables and honey. It is very soluble and upon hydrolysis produces the same amount of glucose and fructose. It does not normally occur in free form by nature, only in germinating grains, however it is the main product of starch hydrolysis. It is less sweet than sucrose and is very soluble in water. It is used in "formulas" for breastfeeding. It is formed when digested by enzymes that break large starch molecules into disaccharide fragments, which can then be broken down into two glucose molecules for easy absorption. It is the main sugar found in milk. It does not exist in plants and is limited almost exclusively to the mammary glands of infants. It is less soluble than other disaccharides and is only sixth as sweet as glucose. When hydrolyzed, it produces glucose and galactose. Lactose stays in the gut more than other disaccharides, thereby stimulating growth beneficial bacteria leading to a laxative effect. One of the functions of these bacteria is the synthesis of certain vitamins in the colon. Lactose intolerance What is it? Biochemistry - Biomolecules 13 - Trisaccharides: They are composed of 3 monosaccharide molecules. Little is found in nature. Found in molasses, brown cane sugar, beets and soybeans. They are not hydrolyzed and cause fermentation via intestinal bacteria causing flatulence. Raffinose = fructose glucose galactose. - Tetrasaccharides: Provide 4 units of monosaccharides. They are present in legumes such as soybeans and lupins. They also do not hydrolyze and cause fermentation via intestinal bacteria causing flatulence. Stachyose = galactose fructose glucose galactose - Fructooligosaccharides: Fructooligosaccharides are natural polymers of fructose that are normally found attached to the parent glucose molecule. They are completely resistant to digestion in the upper gastrointestinal tract and are used almost entirely by colonic bifidobacteria, thus contributing to the integrity of the gastrointestinal mucosa. Currently classified as a dietary fiber. Also called glycans, they are glycosidic-linked hexose polymers in the form of or less soluble and more stable than sugars. A homopolysaccharide is a polysaccharide formed by one type of monosaccharide, for example, with starch, glycogen and cellulose. Heteropolysaccharide contains more than one type of monosaccharides and, among them, we can mention mucins, covering the mucous membrane of the digestive system, heparin, a natural anticoagulant that has in blood plasma and hyaluronic acid, integral structures that connect cells AND pectins, which are components of jelly, marmalade. Most of the nutritional polysaccharides of interest are articular units of glucose, differing only in the type of binding, which is the most abundant form of energy available to living beings. Starch is completely absorbed; Other polysaccharides are partially and sometimes completely indigestible. They do not crystallize or are not palatable. Starch is in the form of amylose - 20% and amylopectin - 80%. Starch is the storage form of carbohydrates in vegetables. Starch granules of various sizes and shapes are enclosed in plant cells with cellulose walls. Cereal grains and tubers are sources of starch. It has a structure similar to that of amylopectin. Its molecules are larger and much more branched than starches. That is, the gap separating the branches is larger in amylopectin than in glycogen. We usually have 350 g of glycogen stored in the liver and muscles. About 1% of muscle mass is glycogen, and 5% of the weight of the liver is glycogen. Only 10 g of glucose circulates in the human body. Important: Glycogen found in the liver has the function of maintaining glucose levels in the body when fasting occurs. They are formed during the process of digestion and also as a result of various commercial processes. As the size of the saccharide molecule decreases, solubility and sweetness increase. Sources of dextrins are wheat flour, rice, honey, peanuts, corn, and beans. Some industrial products have starch and maltodextrin in their composition combinations, the function of which is to regulate the viscosity of the final product. Cellulose is made up of glucose molecules linked by bonds. It has a linear structure, tough, fibrous, stable and insoluble in water. It has no branches. Figure 5 - Cellulose molecule formed exclusively by glucose. Biochemistry - biomolecules 15 It is not digested by humans, as it prevents enzymes from breaking down typical bonds. Except for herbivores, which have symbiotic bacteria and protozoa, which digest cellulose in their digestive tract. AT human body it is important to form a food bolus that facilitates peristaltic movements. However, since they are insoluble in water, this is of great importance in the diet as they are dietary fiber. - Other polysaccharides: - Pectin: non-cellulose polysaccharide, soluble in water, not hydrolyzed by the human body. Because it adsorbs water and forms a gel, it is widely used to make jellies and jellies. It is found in apples, citrus fruits, strawberries and other fruits in smaller amounts, as well as in oats. - Gums and mucus: similar to pectin, except that the galactose units are combined with other sugars and polysaccharides. They are found in plant secretions or seeds and are often added to processed foods to impart special properties. Algae polysaccharides are found in seafood and algae. An example is carrageenan, which is added as a thickening and stabilizing agent in many foods. - Resistant starch: The non-small intestine portion of starch fermented by colon bacteria has short chain end fatty acids and some gases. Digestion: Digestion is a process of enzymatic hydrolysis in which food macromolecules are broken down into simpler units that are absorbed through the intestinal wall into the blood. Some substances, such as inorganic salts and vitamins, do not require digestion, others, such as cellulose, which cannot be digested, are excreted from the body in the intestines in feces. Enzymes responsible for digestion are found in digestive juices such as saliva and pancreatic, gastric and intestinal juices, distinguished along digestive tract. Basically, carbohydrate digestion consists of the hydrolysis of glycosidic bonds by a group of hydrolytic enzymes called glycosidases. That is, the absorbed carbohydrates must be hydrolyzed to primary constituents, which must be absorbed. The digestion process stops when all the glycosidic bonds of the ingested carbohydrates are hydrolyzed. The resulting monosaccharides are then absorbed into the blood. To carry out its action, an enzyme necessarily requires two conditions: pH around neutrality and time to be able to act. The alkaline cavity has this pH, but the bolus feed is swallowed so quickly that salivary amylase does not have enough time. Thus, the task of digesting sugars from the diet is intended to small intestine. Glycosidases from the pancreas or intestinal mucosa. The pancreas secretes pancreatic amylases. Biochemistry - Biomolecules 16 of the digestive compartment, pancreatic amylase enzyme will act because the pH is around neutrality. Also, the food stays there for a long enough time to allow for a long period of contact between the amylase and its substrates. Since bindings 1-4 from the ends of the considered polysaccharides are not affected by amylase, their final action products will be maltose, maltotriose and oligosaccharides. They contain one bond, 1-6 and up to 10 glucose residues, called dextrins. Fructose and galactose are transported by passive transport mechanism and are converted to glucose by the liver and are usually stored as glycogen or used as glucose. There is little fructose and circulating galactose in the bloodstream. Table 4 - Major digestive glycosidases that act on intestinal digestion of dietary carbohydrates. Enzyme Substrate Products Prof. In short: the main carbohydrates in the diet are: starch, sucrose, maltose and lactose. Carbohydrate digestion begins in the mouth under the action of the salivary amylase or ptyalin enzyme, which hydrolyzes the -1.4 starch binding, converting it mainly to disaccharides and dextrins. Due to the highly acidic pH, carbohydrate digestion practically takes place in the small intestine. In the small intestine, dextrins are hydrolyzed to disaccharides by pancreatic amylase enzymes. Through specific enzymes, disaccharides still in the small intestine are hydrolyzed to monosaccharides. Glucose and galactose are actively absorbed by the cells of the intestinal mucosa, sharing a common carrier. Fructose is absorbed at a slower rate and passive process. After leaving the cells of the intestinal mucosa, monosaccharides are transported venous system portal to the liver and excreted into the bloodstream. It has been proven that the most cariogenic carbohydrate is sucrose. This disaccharide can be used as a food substrate for oral bacteria, as well as sucrose in the form of glucose and fructose produced by the action of the sucrase they secrete. In any case, they release protons that dissolve the enamel. In addition, they are an important factor aggregation of microorganisms on the teeth, making up what we call plaque. This aggregation is necessary for the bacterial pathogenic action of bacteria, since only one bacterium cannot accumulate hydrogen protons in the environment, because they are washed and buffered by saliva. Thus, they can resist enamel by lowering the pH of its surface and promoting its dissolution. Among them, we find that an excess of 4 is found in adipocytes, skeletal muscle and cardiac muscle, is insulin sensitive, i.e. Access to insulin is required to bring glucose into the cell. Inside the cell, glucose is converted to pyruvate after acetyl-CoA enters the Krebs cycle, producing hydrogen ions and electrons, passing through the respiratory chain and finally being converted into energy. More detailed information will be considered in energy exchange. Biochemistry - biomolecules 18 Figure 6 - Digestive system. Show some characteristics of each category. They can be called lipids, fats, lipids or fatty substances. Some lipids are not formed endogenously, so these substances are indispensable components of the diet: essential fatty acids and fat-soluble vitamins. However, there are rare exceptions to the solubility of these compounds, since low molecular weight fatty acid monoglycerides are more soluble in water than in organic solvents. Figure 7 - The structure of lipids. This leads to a large number of possible combinations in a single fat molecule. The most common are: palmitic, stearic, oleic and linolenic acids. Triacylglycerols are composed of one molecule of glycerol and three fatty acids in an ester bond. Table 6 - Structure of fatty acid, glycerol and triacylglycerol. Figure 9 - General scheme of the main lipids containing fatty acids. High melting point and more resistant to hydrolysis than triacylglycerols. Due to the high resistance of these compounds to degradation, as well as their insolubility in water, they are often found forming a protective layer in plants and animals. Fatty acid with 20 or common for fats of marine animals. Each individual plant and animal species makes chain fatty acids specific in length and saturation for their unique structural and metabolic needs. In a saturated fatty acid, all non-carbon sites are "saturated" with hydrogen. They are found in higher concentrations in animal foods, although we can find them in foods. plant origin, such as Coconut oil, palm oil, etc. in general, they are solid and pasty, this happens than more chain and more saturated. Figure 10 - Saturated and unsaturated fatty acid binding. Linolenic 18 3 Soybean oil, canola oil, walnuts, wheat germ. Two conventions are used. For example, Δ 9 refers to the double bond between carbon 9 and the second convention, lower Greek letters are used to indicate the placement of carbons in the fatty acid. Essential fatty acids are essential for maintaining the integrity of cell membranes, for growth, reproduction, maintenance of the skin and general functioning of the body; in addition, it helps regulate cholesterol metabolism. Its deficiency can cause the clinical symptoms listed in Table 9. Main symptoms of fatty acid deficiency. clinical symptoms. Naturally found trans fatty acids are obtained from ruminants, but the main industrial source of trans fatty acids is hydrogenated vegetable fat, which is converted into purer and more soft foods in addition to increasing their shelf life. The main food sources of trans fatty acids are: hard or creamy margarines, vegetable creams, biscuits and crackers, cream ice creams, breads, french fries, cakes, tarts, pies, pasta, or any other food containing hydrogenated vegetable fat in its ingredient. From a nutritional point of view, trans fatty acids should be avoided as they inhibit metabolism and utilization of linoleic and linolenic acids and act similarly to atherosclerosis-promoting saturated fatty acids. Many industries reduce or eliminate this fat from their products by replacing it with an interesterified fat, changing the nutritional composition without affecting palatability. An interesterified fat is the result of the physico-chemical modification of fats to form products with excellent characteristics without changing the fatty acid structure. It is used in industry because its raw material is palm oil, which is easily digested and absorbed by the normal metabolic process without the need for hydrogenation, turning into trans fat. It should be noted that since interesterified fat is saturated, its excessive consumption is also harmful to the body. Natural triacylglycerols have different fatty acids in the same molecule. Thermal insulation and mechanical protection act as the main functions for the energy reserve in the housing. Liquids are oils and solids are fats. Chemical composition varies depending on the fatty acid residues and their double bonds, which affects the melting point. Oils are richer in unsaturated fatty acids, so they have more low temperature melting. Fats are richer in saturated fatty acids, so they have more high temperatures melting. Lecithin is the main component of lipoproteins used to transport fats and cholesterol. Its main animal sources are liver, egg yolk and vegetable sources - soybeans, peanuts, spinach and wheat germ. Its amphiphilic quality makes lecithin an ideal additive for binding water and fat to form a stable emulsion. Lecithin is added to food products such as margarine, ice cream, cookies, snacks and sweets. They are widely distributed in the nervous system of animals in the membranes of plants and yeasts. They are not associated with glycerin. Glycoproteins are composed of sphingosine linked to a fatty acid amide and one or more monosaccharide units, usually galactose. Sphingomyelins are composed of: fatty acid, phosphoric acid, choline and amino alcohol. Glycolipids include cerebrosides and gangliosides, containing galactose and glucose, respectively. They are composed of a sphingosine base and very long chain fatty acids. Structurally, both compounds are components of nervous tissue and some cell membranes, where they play a role in lipid transport. In this complex, apolar lipids, polar lipids and proteins form a hydrophilic particle called a lipoprotein. Thus, lipids can be carried into the blood by plasma lipoproteins. It also occurs in high concentrations in the adrenal glands, where adrenocortical hormones are synthesized, and in the liver, where it is synthesized and stored. Cholesterol is a key intermediate in the biosynthesis of a number of important steroids, including bile acids, adrenocortical hormones, and sex hormones. In foods, it is found exclusively in products of animal origin: in high concentrations in egg yolk, kernels and liver and is present in butter, milk creams, cheese, heart, lobster, shrimp, fish egg, whole milk. Its commercial significance is that they mimic the texture of fat, especially in the mouth. Concerns have been raised about long-term effects, especially if fat substitutes are not absorbed, can they bind to essential fatty acids and fat-soluble vitamins and contribute to their malabsorption? However, surveys acknowledge that they are "generally recognized as safe". All excess energy must necessarily be modified and converted into potential chemical energy for storage. Since their development is the result of a complex interaction between genetic, psychological and cultural factors, treatment includes not only control of food intake, but also behavioral and lifestyle changes, including physical activity. Excess cholesterol can accumulate in blood vessels which leads to atherosclerosis. In order to lower your serum cholesterol levels, you need to reduce your intake of foods rich in saturated fat and cholesterol, in addition to your intake of food additives and exercise. - Atherosclerosis: fat deposits that accumulate inside the arteries. Together with hypercholesterolemia, they can contribute to the establishment or worsening clinical picture atherosclerosis and thus belong to risk situations. Dietary control should be restriction of saturated fat and alcohol intake, control of carbohydrates and exercise. Symptoms of the disease usually appear a few months after birth. Patients present with severe degeneration in the nervous system and die, usually around 4 years of age. Niemann-Pick disease causes metal retardation, Krabbe disease causes demineralization and mental retardation and Gaucher disease, causes mental retardation among other symptoms such as splenomegaly, hepatomegaly, bone erosion. Lipid digestion occurs as a result of the action of lipase present in the pancreatic juice, except in newborns where there is some lingual lipase capable of initiating the process of lipid digestion in the mouth. Bile salts act as a detergent, dissolving lipids in the form of an emulsion, which facilitates the action of the enzyme lipase, which hydrolyzes the ester bonds between fatty acids and the first and third carbons of glycerol. Phospholipids are also digested in the small intestine by the enzymes phosphatase and phospholipases. This mixture is absorbed by the cells of the intestinal mucosa. The cell dents of small chain fatty acids enter the bloodstream where they are bound to plasma proteins to be transported. Long chain fatty acids are used to synthesize triglycerides again. A few hours after feeding, most chylomicrons will be removed from the blood via lipoprotein lipase, an enzyme located in the endothelial cells that line the capillaries in many tissues. The fate of fats will be oxidation in muscle cells or stored as fatty acids in subcutaneous fat cells. And the cholesterol carried into the chylomicrons is carried to the liver. Therefore, digestion and absorption of ingested lipids occur in the small intestine, and fatty acids released from triacylglycerols are bound and sent to the muscles and adipose tissue. What products are found? What are its main functions? And, when in excess, what can it cause? Find key features and changes that occur in each of them. It is also well known for its association with atherosclerosis. They are the most abundant lipids in nature, consisting of 3 fatty acid molecules esterified to one molecule of glycerol, i.e. they have 3 acyl groups. Why is it important to understand cholesterol? If this happens in cerebral arteries, it can lead to a stroke. Complete the diagram with the words highlighted in the text. There are a number of factors that contribute to high cholesterol levels. Some of them are modifiable because they relate to a person's lifestyle, while others are inherent and cannot be changed. Amino acids are the basic structural units of proteins. Arranged in specific sequences, amino acids give the identity and character of a protein. Living organisms are made up of 20 types of amino acids. These two amino acids do not fit into this definition: glycine, which has a hydrogen atom, and proline, which contains an imino group, as a radical instead of an amino group, structurally considered an imino acid, but it is included in amino acids because it has properties similar to these, A peptide bond is formed between the carboxyl group of an amino acid and the amino group of another. This binding occurs by the total release of amino acids from one water molecule into each peptide bond formed. Figure 12 - Formation of a dipeptide. Therefore, they must be supplied through food, otherwise malnutrition occurs. Thus, the food should be as diverse as possible so that the body is satisfied with the greatest amount of these amino acids. The main sources of these amino acids are meat, milk and eggs. Lack of these amino acids can lead to weight loss, reduced height, negative nitrogen balance and clinical symptoms. Optional or dispersible amino acids are those that the human body can synthesize from ingested foods. Conditionally essential or conditionally essential amino acids: when the body needs a particular amino acid under some special conditions: malnutrition, surgery, injury. Arginine can be synthesized but is required in large amounts for normal growth and development, and histidine is an essential amino acid for children. From these various building blocks, organisms can synthesize many various products such as enzymes, hormones, antibodies, bird feathers, cobwebs, antibiotics, poisons poisonous mushrooms, among many other products, each with its own activity biological characteristic. They are still found, ions of many metals and some non-metals. . Oils and fats are types of lipids composed primarily of compounds called triacylglycerols.