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Home Masters dr Krzysztof Michalak Wykłady z biochemii Biochemistry in a nutshell - The first introductory lecture - organic compounds

Biochemistry in a nutshell - The first introductory lecture - organic compounds

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Lecture 1 (14.06.2002)


Dear Optimally

I am a doctor optimum for 2 years and during that time regularly read carefully our magazine "Optimally". You can find in it a number of interesting medical information, advice given by doctors Optimal. These two years have been quite a long time. I know that the demand for reliable medical knowledge is high, so I would like to join the mainstream of its promotion.

Much has been written on how to cure various diseases and in the field to gain experience and knowledge, the need for time spent primarily on interviews with patients. For my part, as I mind more theoretical than practical, I would like to offer you a series of articles that przybliżałyby something biochemical basis for Optimal Nutrition. I would do it in such form as to benefit from them both, people who do not have too much knowledge of chemistry, as well as doctors who may be willing to refresh themselves on some details of this matter.

Based on Harper's Biochemistry, the most important book in the world describing exactly all the chemical reactions in the human body, try to explain everything, as it happens, that what we eat is burned or converted to fat or cholesterol. This is a topic that has not been discussed so far in the pages of our newspapers. The reason is, I think, a very high complexity and difficulty of this topic to present complicated issues in a manner accessible to everyone, hence the attempt to treat this as a big challenge. But I will try to center the content between transparency and its accuracy.

In today's article familiarize you with basic information concerning the construction of organic compounds. I think they will be very useful in later chapters, "Biochemistry in a nutshell."


Organic compounds

The basis of most organic compounds is the carbon chain, the carbon atoms arranged in the molecule successively one after another - like beads on a string. For such a chain may attach a variety of other atoms or groups of atoms. Each carbon atom is tetravalent, meaning that it has 4 feet, by which it can connect and other atoms. Two feet are usually occupied by the adjacent carbon atoms, are so two feet free to join something else. Only the extreme carbon atoms in the chain has three free feet.

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-C-C-C-C-C-

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What can join these free feet? The basic atom which joins there is a hydrogen-H. If the carbon chain is surrounded by only hydrogen atoms, then we will have a basic organic compound belonging to the group of hydrocarbons. In short, we write it as follows: CH3 - CH2 - CH2 - CH2 - CH3.These carbon skeletons of different lengths are the basis for the construction of various other organic compounds. Replacing one of the hydrogen atoms on something else we will create a new group of compounds. One of the main options is to convert the hydrogen-H on the group-O-H. As a result of such substitution formed compounds belonging to the group of alcohols.Another option is to join two hydrogen atoms instead of one divalent oxygen atom = O. If such substitution is within the molecule, we are dealing with ketones [and] if such substitution and takes place at its end formed aldehyde [ii]. If the extreme carbon atom at one time will be łapce-OH group and the other two oxygen = O, then arises very important in the biochemistry of the carboxyl group-COOH. The presence of such a group makes the molecule becomes acid. They contain almost all of it organic acids, including fatty acids.

For the carbon chain may be essentially connect all kinds of atoms and chemical groups to form various compounds. Many of them plays an important role in the human body. But mention here as yet only two groups: a group of H2PO4 and phosphate-amine-NH 2.

When it comes to a phosphate group, a combination of the carbon chain forms a so-called. high-energy bond. Disconnection of the phosphate group is connected with emission collected at this binding energy. Compounds having the group collects a portion of the rechargeable energy for future use.One of the most important of such compounds, batteries in the body called acid is in short adenozynotrójfosforowy ATP - the primary carrier of energy. It is synthesized during the combustion of protein, fats and carbohydrates, and then used in a cell for a variety of purposes: for example, muscle contraction and synthesis of other chemicals. The amino group-NH2 and is important because it is present in each amino acid and plays an important role when connecting to the amino acids in protein molecules.


What are proteins, fats and carbohydrates?

As surely everyone knows Optimal certainly, there are three basic types of chemical compounds, of which our body is built and which make up our food.How are they constructed? What follows from this construction? At first let's fire, those whose structure is relatively simple means:


CARBOHYDRATES

Carbohydrates are compounds which generally, the total scheme of construction could include the formula Cn (H2O) n. As you can see are those in which one carbon atom in a molecule of water falls. Since the carbon atom has a mass 12j.ma [iii] and water molecule 18j.ma You can with some approximation to say that carbohydrates are a mixture of coal and water in a ratio of 2:3. Specifically, carbohydrates are compounds in which one carbon atom with two hydrogen atoms are replaced by one atom of oxygen = O, while the remaining carbon atoms and one hydrogen-H is converted to a group-OH. The most elementary is the sugar glucose in the body, which consists of six carbon atoms. Its design can thus be written as: CH 2 OH - CHOH - CHOH - CHOH - CHOH - CHO. [Iv] The chemical formula is C6H12O6 while. Almost all the carbohydrates that we eat are spread out or transformed into this particular molecule. Another key for us is the simple sugar fructose. It is present in large quantities in fruits. The combination of 1 molecule of glucose and fructose gives sucrose, or sugar cukierniczki. This connection can be written as follows: C6H12O6 (glucose) + C6H12O6 (fructose) ® C12H22O11 (sucrose) + H2O. The reaction of this linked to a comic (at least for me) observation. Food sugar chemically pure sucrose, which when dissolved in water decomposes back into glucose and fructose by joining a water molecule. Mass of sugar as a result of dissolution increases so slightly and with 100g of sugar is getting food and 52.5g 52.5g glucose fructose. So you can safely say it is scientific and true that the sugar content in sugar is 105%.

Let us say a few words about the complex sugars, such as potato starch or glycogen in the liver and muscles. They are formed by combining the molecules of simple sugars in the chain. Connected to two consecutive molecules of sugar accompanied by disconnecting one molecule of water.This reaction can be briefly written as follows:

C6H12O6 ® n (C6H10O5) n + n H2O.

With this sugar can be condensed in the tissues more easily stored.


FATS.

For fat to be a number of chemical compounds, among which one can distinguish various groups. The two most important for us are:

1st triglyceride fats or appropriate;

2nd steroids;

It should however be mentioned even by name in this place also other groups of fats, such as sphingolipids, cerebrosides, phospholipids, glycolipids, sulfolipidy, aminolipidy or lipoproteins. They play their important roles in the body, however, given that they are not quantified in our body a lot, and their lack of Optimal Diet does not threaten us, yet we will not be too hard for them to dwell.

Let's look at the first group, ie triglicerydom. Triglyceride molecule is formed from a combination of 1 molecule of glycerol and three fatty acid molecules.Glycerol [v] is one of the basic molecules of indirect pathway of glucose combustion. Chain is composed of three carbon atoms, each of them is a group-OH. For each of the 3-OH group is attached via its-COOH group of a fatty acid. It is the fatty acids are quantitatively the main component of triglycerides. We have to stay with them a bit longer, since they can be very different.



Fatty Acids

Fatty acid is composed of carbon chain surrounded on all sides hydrogens.Only the first carbon atom forms a carboxyl group-COOH. Fatty acids are naturally occurring in most even number of carbon atoms, as they are synthesized from units dwuwęglowych. The two essential fatty acids are palmitic acid, [vi] (16 carbons) and stearic [vii] (18 carbon atoms). These are the basic building block of all cell membranes. These are saturated fats, because the number of hydrogen atoms around the carbon chain is the largest that can be. The second group of fatty acids are unsaturated. They are not full fill the hydrogens of all places. The most common acid is an unsaturated 18-carbon oleic acid [viii], which is missing two hydrogen atoms at carbon atoms 9 and 10 Instead, between these coals appears so. double bond-C = C-. The more double bonds, the less the hydrogen molecule and contains the more unsaturated fatty acid is given. The number of double bonds in the molecule reaches up to 6. Unsaturated fatty acids are generally liquid at room temperature, while the saturated are solid consistency. It is important here to note that the double bond appearing in the molecule stiffens her at this point - around the double bond can be no mutual rotation of the ends of the molecules. There are thus two kinds of settings carbon chain: cis and trans. This is illustrated in figure below:



In nature, there is mainly the cis form. Bending of the molecule in the cis form causes the molecules lying side by side of different fatty acids are more difficult to adjust to each other, it increases the "liquidity" of the whole fat.Trans form is created primarily as a byproduct during the process of hydrogen saturation of fatty acids in the production of margarine. A small part of the trans fatty acids derived from dietary fats of ruminants, in which they arise in the gastrointestinal tract by the action of microorganisms.

Let us now return back to triglycerides. Layout of different fatty acids (longer or shorter, more or less saturated), which bind to specific 3-OH groups of glycerol can be very diverse. This does not change very much the fact that the main mass of the molecule, as well as the energy value is contained in the three fatty acids. Glycerol is the only link to them. But in the process of synthesis and degradation of triglycerides in adipose tissue where it will play an important role. This topic will be discussed in more detail, however, on one of the future lectures.

The second group of fats important for Optimal (actually irrelevant, only tea plantation much confusion) is a steroid. The most important, a key representative of this group of compounds is cholesterol. Construction of cholesterol molecules is quite complex and I will discuss it more closely when the time comes. Today, I will cite only its chemical formula: C27H46O.Cholesterol once absorbed or synthesized can not be decomposed or burned. So it is not fuel. The only way to remove cholesterol from the body to replace him on bile acid and expel the stool.


PROTEIN

The basis for the construction of all proteins are amino acids. Amino acids constituting the protein is 20 There's also a few amino acids metabolically important for us not so very important. As the name implies, these compounds are organic acids containing an amino group. Must therefore have a carboxyl group-COOH and amine-NH 2. The amino acids forming the protein both these groups are placed at the first carbon, so one end of the molecule is the same in all amino acids [ix]. As you might guess, is what differentiates the various amino acids, the other end of the molecule. Some amino acids are able to synthesize themselves, but some must be supplied in the diet. These essential are: Histidine, Leucine, Isoleucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan and Valine. It is easy to imagine that they would be evolutionarily closer to the food eaten human tissue, the more the proportion of amino acids in the diet will be closer to the proportion of 20 amino acids in the human body. A low value of plant proteins from the fact that some amino acids necessary for us they do not contain at all. The most valuable are certainly proteins contained in natural foods for the growing young animals: egg and milk. The set, you can even throw in a protein to farm animals, provided, however, that once we eat the whole animal (including liver, skin, lungs, etc.) and not just the muscles in which the proportion of amino acids is slightly different.

Proteins are complex molecules formed by the combination of a long chain of several hundred to several thousand amino acids. These amino acids are present in individual proteins in a precise genetic sequence and quantity. To synthesize a protein, it is necessary so the presence of amino acids in cell ALL, which in a given protein is present and preferably in the same proportion in which they occur in the synthesized protein. If you will be missing at least one amino acid (especially if it is a necessary amino acid) protein synthesis does not occur, and all ready for the synthesis of amino acids will be burned. The body will wait for a moment until all the amino acids are available.

I think that as the first lecture, you just have new information. I invite you to the next in the next issue of Optimal. Topics subsequent lectures is not yet finally determined, so if you have any requests, it is willing to adjust to them.Greetings to all.

[And] appears when the compound of the general scheme R1 - CO - R 2.

[Ii] in the chemistry of the aldehyde group recorded as: R - CHO.

[Iii] j.m.a. is called. atomic mass unit. 1 gram equals 6023 × 1023 j.m.a. Just like a dozen is 12 pieces, so mole in chemistry is 6023 × 1023 units. For example: 1 mole of carbon atoms C weighs 12g, 1 mole of oxygen atoms O weighs 16g, 1 mol H atoms of hydrogen weighs 1 g, 1 mole of water molecules H2O weighs 18g (16g 1 g 1 g) and 1 mol of glucose C6H12O6 weighs 180g ( 6 × 12 × 12g + 1g + 6 x 16g = 180g). So we see that the mass of each particle is the sum of the masses of all its atoms.

[Iv] In fact, the glucose molecule to make some internal transformation, which makes the molecule has a ring shape. It is also important, which side of the carbon chain joins the group OH. The glucose molecule, this system is strictly defined. Fructose or galactose have the same chemical formula, but only a different distribution of-OH groups in the molecule.

[V] glycerol formula is: CH 2 OH - CHOH - CH2OH. Molecular weight - 92g.

[Vi] palmitic acid is a formula: CH3 - CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-COOH. In short: CH3 - (CH2) 14-COOH, or globally: C16 H32O2. Molecular weight - 256g.

[Vii] is a formula of stearic acid: CH 3 - (CH 2) 16-COOH, or globally: C18 H36O2. Molecular weight - 284g.

[Viii] This pattern of oleic acid: CH3 - CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH = CH-CH2-CH2-CH2-CH2-CH2-COOH. In short: CH3 - (CH2) 7 - CH = CH - (CH 2) 7 - COOH, or globally: C18 H34O2.

[Ix] The general formula of amino acids is R - CH (NH2) - COOH. R - is a carbon chain specific to each amino acid. When the chain may additionally be-OH (serine, threonine), carboxyl group (aspartic acid, glutamic acid), nitrogen N in various configurations (arginine, lysine, histidine, asparagine, glutamine), sulfur S (cysteine, methionine), so. aromatic (phenylalanine, tyrosine, tryptophan), or non-aromatic ring (proline, hydroxyproline). "Naked" carbon chains are glycine, alanine, valine, leucine and isoleucine.

Author: Krzysztof Piotr Michalak. All rights reserved.

 

Biochemistry in a nutshell - The first introductory lecture - organic compounds
 

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