Sugar compounds include monosaccharides, polymers and derivatives of monosaccharides.

Monosaccharide molecules are aldehydes or ketones with multiple hydroxyl groups.

Chemical concept of carbohydrate compounds: monosaccharide is polyhydroxyaldehyde or polyhydroxyketone and its cyclic hemiacetal or derivative. Polysaccharides are polymers of monosaccharide condensation.

General molecular formula: Cm(H2O)n

However, not all sugars conform to this general formula, and not all sugars conform to this general formula.

This is just a general formula for most sugars.

Carbohydrate is only the largest form of sugar. We think that sugar is a carbohydrate in a narrow sense.

monose

Put forward such as glyceraldehyde

Pentose, pentose, such as ribose, deoxyribose

Hexose, such as glucose and fructose (both chemical formulas are C6H 12O6).

disaccharide

Sucrose, maltose and lactose

Their chemical formula is (C6H 12O6)2.

polysaccharide

Starch, cellulose and glycogen

Their chemical formula is (c6h10o5) n.

Elaborate in detail

Classification: monosaccharide, disaccharide, oligosaccharide (oligosaccharide), polysaccharide, complex carbohydrate.

The biological functions of carbohydrates mainly include:

1 as bioenergy

As a carbon source for the biosynthesis of other substances.

3 as the structural substance of organisms

Glycoproteins and glycolipids have many physiological functions, such as cell recognition and immune activity.

Monosaccharide-the simplest sugar. Monosaccharide molecules contain many hydrophilic groups, which are easily soluble in water and insoluble in organic solvents such as ether and acetone. Simple monosaccharides are generally polyhydroxyaldehydes or polyhydroxyketones with 3-7 carbon atoms, and their constituent elements are C, H, O glucose, fructose and galactose. Glucose is the main energy substance of life activities, ribose is the component of RNA, and deoxyribose is the component of DNA. The molecular formulas of glucose and fructose are: C6H 12O6. They are isomers.

Oligosaccharide (Oligosaccharide)-It is formed by polymerization of 2- 10 monosaccharide molecules. Monosaccharide can be formed after hydrolysis.

Disaccharide-disaccharide is a glycoside formed by dehydration of two monosaccharide molecules, and aglycone is another monosaccharide molecule. Disaccharide hydrolyzes to form two molecules of monosaccharide. Such as lactose, sucrose and maltose. Sucrose and maltose can be hydrolyzed into monosaccharides for energy supply. Their molecular formulas are C 12H22O 1 1. It also belongs to isomers.

Trisaccharide-a monosaccharide that forms three molecules after hydrolysis. Like cotton candy. Fixed powder is the storage material, cellulose is the cell wall, and glycogen is the energy storage material.

tetrose

pentose

Polysaccharide-It is polymerized by more than 10 monosaccharide molecules. After hydrolysis, a variety of monosaccharides or oligosaccharides can be produced. According to whether the monosaccharide composition produced after hydrolysis is the same, it can be divided into:

Homopolysaccharide-Homopolysaccharide consists of a monosaccharide, which produces the same monosaccharide after hydrolysis. Such as gum Arabic, glycogen, starch, cellulose, etc. The expression of starch and cellulose is (C6H 10O5) n, but they are not isomers because their n numbers are different. Wherein starch n

Heteropolysaccharide-heteropolysaccharide is composed of many monosaccharides, which are hydrolyzed to form different monosaccharides. Such as mucopolysaccharide and hemicellulose.

Complex carbohydrates (). A product in which the reducing end of carbohydrate is combined with protein or lipid. The relative sweetness of several sugars;

Fructose 175 (the sweetest sugar)

Sucrose 100

Glucose 74

Various sugar chemical properties of maltose 32: The aldehyde group of glucose is relatively active, and semi-acetal reaction will occur to form semi-acetal hydroxyl group and pyridine ring. The conformation energy of this molecule is low, so it is more scientific and reasonable to write it as a ring.

In addition, glucose may also form furan rings in hemiacetal reaction, but the proportion is low, below 2%.

Glucose cyclization is not flat, and it often forms a boat or chair conformation, which is relatively stable.

Galactose is an isomer of glucose, and common D- galactose is a C4 isomer of D- glucose. That is, they have different hydroxyl groups on carbon 4.

Fructose does not contain aldehyde group, but has carbonyl group on the second carbon, so it often forms five-membered furan ring.

Two. The concept of fat: lipid is the general name of oil, fat and lipid. The fat in food is mainly fat. Generally speaking, liquid at room temperature is called oil, and solid at room temperature is called fat. The chemical elements contained in fat are mainly C, H, O, and some also contain elements such as N and P. ..

Fat is a triacylglyceride composed of glycerol and fatty acids, in which the molecule of glycerol is relatively simple, but the types and lengths of fatty acids are different. Therefore, the nature and characteristics of fat mainly depend on fatty acids, and the types and contents of fatty acids contained in fat in different foods are different. There are more than 40 kinds of fatty acids in nature, so various fatty acid triglycerides can be formed. Fatty acids usually consist of 4 to 24 carbon atoms. Fatty acids are divided into three categories: saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids.

Fat is soluble in most organic solvents, but insoluble in water. [Edit this paragraph] Classification of lipids Fat is a triglyceride synthesized from glycerol and three molecular fatty acids.

(1) Neutral fat: triglyceride, which is the main component of lard, peanut oil, soybean oil, vegetable oil and sesame oil.

(2) Lipids include phospholipids: lecithin, cephalin and inositol phospholipids.

Glycolipids: cerebroside and ganglioside.

Lipoprotein: chylomicron, very low density lipoprotein, low density lipoprotein and high density lipoprotein.

Steroids: cholesterol, ergosterol, corticosteroids, cholic acid, vitamin D, androgen, estrogen and progesterone.

In nature, mixed triglycerides are the most abundant, accounting for 98% of the fat in food and more than 28% in the body. All cells contain phospholipids, which are structures in cell membranes and blood, especially in the brain, nerves and liver. Lecithin is one of the most abundant phospholipids in diet and body. Four kinds of lipoproteins are the main means to transport lipids in the blood. [Edit this paragraph] The biological functional lipid of fat refers to a kind of substances which have great differences in chemical composition and structure, but all have the same characteristics, that is, they are insoluble in water and soluble in nonpolar solvents such as ether and chloroform. Generally speaking, lipids can be divided into five categories according to their composition, namely, simple lipids, complex lipids, terpenoids and steroids and their derivatives, derived lipids and bound lipids.

Lipids have important biological functions. Fat is the energy provider of organisms.

Fat is also an important component of organism. For example, phospholipid is an important component of biofilm, and oil is the storage and transportation form of fuel needed by body metabolism. Lipid substances can also provide essential fatty acids and fat-soluble vitamins dissolved in animals. Some terpenoids and steroids, such as vitamins A, D, E, K, cholic acid and steroid hormones, have nutritional, metabolic and regulatory functions. Lipid substances on the surface of organisms have protective effects such as preventing mechanical damage and heat emission. As the surface substance of cells, lipids are closely related to cell recognition, species specificity and tissue immunity.

To sum up, fat has the following physiological functions:

1. Substances that store and supply energy in organisms. 1g fat is decomposed into carbon dioxide and water in the body and generates 38KJ(9 kcal) of energy, which is more than twice as high as that of 1g protein or 1g carbohydrate.

2. It constitutes some important physiological substances. Fat is the material basis of life and one of the three components of human body (protein, fat and carbohydrate). Phospholipids, glycolipids and cholesterol constitute the lipid layer of cell membrane, and cholesterol is the raw material for synthesizing bile acid, vitamin D3 and steroid hormones.

3. Maintaining body temperature, protecting internal organs and buffering external pressure can prevent excessive body temperature loss, reduce body temperature loss and keep body temperature constant. It can also prevent external heat energy from being transmitted to the body and maintain normal body temperature. The fat pad around the viscera has the function of buffering the impact of external force and protecting the viscera. Reduce the friction between internal organs.

4. Provide essential fatty acids.

5. Important sources of fat-soluble vitamins Cod liver oil and cream are rich in vitamins A and D, and many vegetable oils are rich in vitamin E. Fat can also promote the absorption of these fat-soluble vitamins.

6. Increasing satiety Fat stays in the gastrointestinal tract for a long time, so it has the effect of increasing satiety. Biodegradation of fat: Under the action of lipase, fat is hydrolyzed into glycerol and fatty acids. Glycerol is converted into dihydroxyacetone phosphate by phosphorylation and dehydrogenation, which is included in the sugar metabolism pathway. Fatty acids react with ATP and CoA under the action of fatty acyl-CoA synthetase to produce fatty acyl-CoA. With the help of carnitine: fatty acyl-CoA transferase system on the mitochondrial inner membrane, fatty acyl-CoA enters the mitochondrial matrix, is degraded into acetyl-CoA by β-oxidation, and is completely oxidized after entering the tricarboxylic acid cycle. The β -oxidation process includes four steps: dehydrogenation, hydration, re-dehydrogenation and thiolysis. FADH2, NADH, acetyl coenzyme A and fatty acyl coenzyme A with less than two carbon atoms are formed in each β -oxidation cycle. In addition, in some tissues and cells, α -hydroxy fatty acids or CO2 and fatty acids with one less carbon atom are produced by α-oxidation. The corresponding dicarboxylic acids are formed by ω-oxidation.

Germinated oilseeds and some microorganisms have glyoxylic acid circulation pathway. Malic acid can be synthesized from acetyl coenzyme A produced by β -oxidation of fatty acids, which provides carbon source for gluconeogenesis and other biosynthesis. The two key enzymes in glyoxylic acid cycle are isocitrate lyase and malate synthase. The former catalyzes the cleavage of isocitrate into succinic acid and glyoxylic acid, while the latter catalyzes glyoxylic acid and acetyl coenzyme A to produce malic acid. [Biosynthesis of fat: Biosynthesis of fat includes three aspects: ab initio synthesis of saturated fatty acids, extension of carbon chain of fatty acids and generation of unsaturated fatty acids. The site of de novo fatty acid synthesis is cell sap, which needs the participation of CO2 and citric acid, and C2 donor is acetyl coenzyme A produced by sugar metabolism. There are two enzyme systems involved in the reaction, namely acetyl-CoA carboxylase and fatty acid synthase. Firstly, acetyl-CoA was generated under the catalysis of acetyl-CoA carboxylase. Then, under the catalysis of fatty acid synthetase system, acetyl-CoA was used as acyl carrier, acetyl-CoA as C2 acceptor and malonyl-CoA as C2 donor. After several reaction steps of condensation, reduction, dehydration and re-reduction, butyryl -ACP with four carbon atoms was obtained. Each extended cycle consumed one molecule of malonyl-CoA and two molecules of NADPH until soft acyl -ACP was generated. The product is reactivated as soft acyl coenzyme A, which participates in fat synthesis or extends to C 18, C20 and a small amount of fatty acids with long carbon chains in microsomal system or mitochondrial system. In eukaryotic cells, saturated fatty acids are further generated into various unsaturated fatty acids with the participation of O2 and the catalysis of specific desaturase system. Higher animals cannot synthesize linoleic acid, linolenic acid and arachidonic acid, and must rely on food supply.

3- glycerophosphate and two molecules of fatty acyl-CoA generate phosphatidic acid under the action of glycerophosphate transacylase, and phosphatidic acid becomes diacylglycerol under the catalysis of phosphatase, and finally fat is generated under the catalysis of diacylglycerol transacylase. Chemical and physical properties: molecular weight:

CASNo.:

Properties: The carboxyl group of acid is connected with aliphatic hydrocarbon group. According to the different aliphatic hydrocarbon groups, it can be divided into (1) saturated fatty acids and acid-containing saturated hydrocarbon groups. For example, HCOOH formate, CH3COOH acetate, CH3 (CH2) stearate16cooh palmitate CH3(CH2) 14COOH. (2) Unsaturated fatty acid, an acid containing unsaturated hydrocarbon groups. For example, acrylic acid CH2=CHCOOH, oleic acid CH3 (CH2) 7ch = CH (CH2) 7cooh. (3) cycloaliphatic carboxylic acids, in which carboxyl groups are attached to cyclic hydrocarbon groups. For example, cyclohexane carboxylic acid C6H 1 1COOH. Triglycerides of many fatty acids are the main components of oils and fats, so they can be prepared from oils and fats by hydrolysis. It can also be synthesized artificially. Low carbon number is colorless liquid, with pungent smell and easy to dissolve in water. Carbon number is oily liquid, slightly soluble in water, and it smells of sweat. Those with high carbon number are solid and insoluble in water. Fatty acids can react with alkali to form salts and with alcohol to form esters. Used to make soap, synthetic detergent, lubricant and cosmetics. Three. Vitamins, also known as vitamins, are a kind of organic substances necessary to maintain human life activities and important active substances to maintain human health. The content of vitamins in the body is very small, but it plays an important role in the process of human growth, metabolism and development. Although the chemical structures and properties of various vitamins are different, they are similar as follows: ① Vitamins exist in food in the form of provitamins (vitamin precursors); ② Vitamins are not components of tissues and cells, and do not produce energy. Their function is mainly to participate in the regulation of metabolism. ③ Most vitamins can't be synthesized or the synthetic amount is not enough to meet the body's needs. You must always get it from food. ④ The amount of vitamins needed by human body is very small, and the daily requirement is often calculated by mg or μg, but once it is lacking, it will cause the corresponding vitamin deficiency and do harm to human health. Vitamins, unlike carbohydrates, fats and protein, account for only a small proportion in natural foods, but they are also necessary for human body. Some vitamins, such as B6 and K, can be synthesized by bacteria in the intestinal tract of animals, and the synthetic amount can meet the needs of animals. Animal cells can convert tryptophan into nicotinic acid (a B vitamin), but the yield is not enough. Vitamin C can be synthesized by animals other than primates (including humans) and guinea pigs. Plants and most microorganisms can synthesize vitamins by themselves without external supply. Many vitamins are components of helper groups or coenzymes.

Some small amounts of organic compounds necessary for human and animal nutrition and growth play an extremely important role in the metabolism, growth, development and health of the body. If a vitamin is lacking for a long time, it will cause physiological dysfunction and some diseases. Generally obtained from food. There are dozens of vitamins found now, such as vitamin A, vitamin B, vitamin C and so on. The discovery of vitamins is one of the greatest discoveries of the 20th century. 1897, C. Aikman found that only eating finely ground white rice in Java can cause beriberi, and unpolished brown rice can cure this disease. It was also found that substances that can cure beriberi can be extracted with water or alcohol, which was called "water-soluble B" at that time. 1906 proves that food contains "auxiliary factors" other than protein, lipids, carbohydrates, inorganic salts and water, which are extremely small substances necessary for animal growth. 19 1 1 year C. Feng Ke identified that the substance in brown rice that can fight beriberi is amine (a nitrogen-containing compound), which is necessary for maintaining life. It is suggested to name it "vitamin". That is, active amine, which means "active amine" in Chinese. Later, many vitamins were discovered one after another, with different chemical properties and physiological functions. It is also found that many vitamins do not contain amine or nitrogen at all, but only use the name of Funk, and only remove the last letter "e". The first vitamin B was later proved to be a vitamin B complex. After purification and separation, several substances were found, but their properties and distribution in food were similar, and most of them were coenzymes. Some supplies must be balanced with each other, such as vitamin B 1, B2 and PP, otherwise physiological functions may be affected. Vitamin B complex includes pantothenic acid, nicotinic acid, biotin, folic acid, vitamin B 1 (thiamine), vitamin B2 (riboflavin), pyridoxine (vitamin B6) and cyanocobalamin (vitamin B 12). Some people also add choline, inositol, p-aminobenzoic acid (p-aminobenzoic acid), carnitine and lipoic acid to the B complex. Overview and classification of vitamins Vitamins are essential organic compounds in human metabolism. The human body is like an extremely complex chemical plant, constantly carrying out various biochemical reactions. This reaction is closely related to the catalysis of enzyme. Coenzymes must participate in the activities of enzymes. It is known that many vitamins are coenzymes of enzymes or constituent molecules of coenzymes. Therefore, vitamins are important substances to maintain and regulate the normal metabolism of the body. It can be considered that the best vitamins exist in human tissues in the form of "bioactive substances".

The vitamin content in food is less, and the human body needs little, but it is an indispensable substance. If there is a lack of vitamins in the diet, it will cause metabolic disorder and cause vitamin deficiency. If vitamin A is lacking, there will be night blindness, dry eyes and dry skin; Lack of vitamin d can cause rickets; Lack of vitamin B 1 can cause beriberi; Lack of vitamin B2 can lead to cheilitis, angular stomatitis, glossitis and bursitis; Lack of PP can cause boils; Lack of vitamin B 12 will lead to pernicious anemia; Lack of vitamin c can lead to scurvy.

Vitamins are a huge family, and there are dozens of known vitamins, which can be roughly divided into fat-soluble and water-soluble. (See the table below for details) Some substances are similar to some vitamins in chemical structure and can be converted into vitamins through simple metabolic reactions. Such substances are called provitamins. For example, beta-carotene can be converted into vitamin A; 7- dehydrocholesterol can be converted into vitamin d 3；; However, tryptophan has to undergo many complicated metabolic reactions to become nicotinic acid, which cannot be called provitamin. Water-soluble vitamins are absorbed from the intestine and circulated to the tissues needed by the body. Most of the excess vitamins are excreted through urine, and very little is stored in the body. Most fat-soluble vitamins are absorbed by bile salts and reach various organs in the body through the lymphatic system. The body can store a lot of fat-soluble vitamins. Vitamins A and D are mainly stored in the liver, vitamin E is mainly stored in adipose tissue in the body, and vitamin K is less stored. Water-soluble vitamins are easily soluble in water and insoluble in nonpolar organic solvents, so they are rarely stored in the body after absorption, and the excess is mostly excreted in urine; Fat-soluble vitamins are soluble in nonpolar organic solvents, but insoluble in water. They can be absorbed by the body with fat and stored in the body at a low excretion rate. Classification name discovery and another name, fat-soluble anti-dry eye vitamin (vitamin A), also known as cosmetic vitamin, were discovered by Elmer McCollum and M. Davis at 19 12 to 19 14. It is not a single compound, but a series of derivatives of retinol (retinol is also translated into vitamin A alcohol and rosin oil), also known as anti-dry eye vitamin cod liver oil and green vegetables.

Water-soluble thiamine (vitamin B 1) is produced in casimir? 6? 1 was discovered by Feng Ke in 19 12 (for example, 19 1 1). It usually exists in organisms in the form of thiamine pyrophosphate (TPP). Yeast, grain, liver, soybean, meat.

Water-soluble riboflavin (vitamin B2) was found in 1926 by D.T. Smith and Hendrick, for example. Vitamin G is also called yeast, liver, vegetables and eggs.

Conrad Elvehjem discovered water-soluble nicotinic acid (calcium pantothenate) in 1937. Also known as vitamin P and vitamin PP, including nicotinic acid (niacin) and nicotinamide (nicotinamide), all belong to pyridine derivatives. Nicotinic acid, nicotinic acid yeast, grain, liver, rice bran.

Roger williams discovered water-soluble pantothenic acid (vitamin B3) in 1933. Also known as pantothenic acid yeast, grain, liver and vegetables.

The water-soluble pyridoxine (vitamin B6) was discovered by Paul Georgi in 1934. Include pyridoxine, pyridoxal and pyridoxamine yeast, grains, livers, eggs and dairy products.

Water-soluble biotin (vitamin B7) is also called vitamin H or coenzyme R yeast, liver and grain.

Water-soluble folic acid (vitamin B9) is also called pteroyl glutamic acid, pteroyl glutamic acid, vitamin M or leaf essence, vegetable leaf and liver.

Carl Fox and Alexander Todd discovered the water-soluble cyanocobalamin (vitamin B 12) in 1948. Also known as cyanocobalamin or [[coenzyme B 12]] liver, fish, meat and eggs.

The water-soluble choline was discovered by Maurice Gobley in 1850. Liver, egg yolk, dairy products and soybeans, one of the B vitamins.

Water-soluble inositol cyclohexanol, vitamin B-h heart, meat

Water-soluble ascorbic acid (vitamin C) is prepared by James? 6? 1 Linde was discovered in 1747. Also known as ascorbic acid fresh vegetables and fruits

Fat-soluble calciferol (vitamin D) was discovered by Edward Mellanby in 1922. Also known as calciferol and anti-rickets vitamins, there are mainly vitamin D2, ergocalciferol and vitamin D3, and cholecalciferol. This is the only vitamin that can be synthesized in a small amount, such as cod liver oil, egg yolk, dairy products, yeast and so on.

Fat-soluble tocopherol (vitamin E) was discovered by Herbert Evans and Catherine Bishop in 1922. There are mainly four kinds of eggs, liver, fish and vegetable oil: α, β, γ and δ.

Henrik Dam discovered fat-soluble naphthoquinone (vitamin K) in 1929. It is the floorboard of a series of naphthoquinone derivatives, mainly including natural vitamin K 1 from plants, vitamin K2 from animals, and synthetic vitamins K3 and K4. Also known as frozen vitamins spinach, alfalfa, cabbage, liver.

The definition of characteristic vitamins requires that vitamins meet four characteristics before they can be called essential vitamins:

Exogenous: the human body can't synthesize it itself (vitamin D can be synthesized in a small amount, but it is still regarded as an essential vitamin because of its importance), so it needs to be supplemented by food;

Traces: the human body needs little, but it can play a huge role;

Regulatory: vitamins must be able to regulate human metabolism or energy conversion;

Vitamin specificity: Without certain vitamins, people will show a unique pathological state.

According to these four characteristics, the human body needs 13 vitamin, which is also commonly known as 13 essential vitamin. Physical and chemical properties: 1. Vitamin E is a fat-soluble vitamin, also known as tocopherol, and is one of the most important antioxidants.

The daily reference dose of adult nutritional vitamins: vitamin A is1.5 mg; Vitamin e 30mg.

Many health care products purchased now are also based on mg, so there is a conversion problem between IU (International Unit) and mg (Mg), which is convenient for everyone to measure and compare the dosage. I'm afraid a large dose will do more harm than good.

The conversion values of different elements are different (international regulations):

Vitamin A: 1IU = 0.3 ug and 1000ug= 1mg.

Vitamin E: 1IU = 1mg.

After calculation, the supplement amount of normal adults: vitamin A: A: 1.5mg is 5000IU；; Vitamin E is 30IU.

Function: Vitamin E has the most extensive function in human body, which is bigger than any nutrient, so it is called "guardian". It has a good antioxidant effect in the body, that is, it reduces cell aging. Maintain the integrity of red blood cells, promote cell synthesis, resist pollution and infertility.

Lack of vitamin E can lead to leg diseases such as atherosclerosis, anemia, cancer and cataract in the elderly. Form a scar; Will make the teeth yellow; Cause myopia; Causing disability and mental retardation; Cause male sexual dysfunction; Prostate hypertrophy and so on.

Source: Kiwi, nuts (including almonds, hazelnuts and walnuts), sunflower seeds, corn, cold-pressed vegetable oil, including corn, safflower, soybean, cottonseed and wheat germ (the most abundant one), spinach and kale, sweet potato and yam. Lettuce, cabbage and cauliflower are vegetables with high vitamin E content. Milk, eggs and cod liver oil also contain some vitamin E2. Vitamin c, vitamin cIUPAC Chinese name.

(r)-3,4-dihydroxy -5-((S)- 1, 2- dihydroxyethyl) furan -2(5H)- 1 conventional molecular formula C6H8O6 molecular weight176.12ucas No.50.

Fluorescence wavelength: recommended intake of soluble water-soluble vitamins without nm vitamins: 5mg daily maximum intake causes diarrhea; Lack of symptoms; Excessive symptoms of scurvy; Diarrhea mainly comes from fresh fruits and vegetables. Unless otherwise specified, the physical data are all from vitamin C under standard conditions, also known as L- ascorbic acid, which is an essential nutrient for higher primates and other few organisms. Ascorbic acid can be produced by metabolism in most organisms, but human beings are the most obvious exception. As we all know, lack of vitamin C can lead to scurvy. The effective group of vitamin C is ascorbic acid ion. In organisms, vitamin C is an antioxidant, because it can protect the body from the threat of oxidants, and it is also a coenzyme. However, because vitamin C is an essential nutrient, its use and recommended daily dose are often discussed. When it is used as a food additive, vitamin C becomes an acidity regulator of antioxidants and preservatives. Many E prefix numbers (e #) contain vitamin C, and different numbers depend on their chemical structures, such as E300 is ascorbic acid, E30 1 is sodium ascorbate, E302 is calcium ascorbate, E303 is potassium ascorbate, E304 is palmitate ascorbate and stearic acid ascorbate, and E3 15 is pyrethrin isoascorbate.