Bioorganic chemistry

HOC is a science that studies the biological function of organic substances in the body.

BOH arose in the 2nd half of the twentieth century. The objects of its study are biopolymers, bioregulators and individual metabolites.

Biopolymers are high-molecular natural compounds that are the basis of all organisms. These are peptides, proteins, polysaccharides, nucleic acids (NA), lipids, etc.

Bioregulators are compounds that chemically regulate metabolism. These are vitamins, hormones, antibiotics, alkaloids, medications, etc.

Knowledge of the structure and properties of biopolymers and bioregulators allows us to understand the essence of biological processes. Thus, the establishment of the structure of proteins and NAs made it possible to develop ideas about matrix protein biosynthesis and the role of NAs in the preservation and transmission of genetic information.

BOX plays a major role in establishing the mechanism of action of enzymes, drugs, vision, respiration, memory, nerve conduction, muscle contraction, etc.

The main problem of BOX is elucidating the relationship between the structure and mechanism of action of compounds.

BOX is based on organic chemistry material.

Lecture 1.

Isomerism of organic compounds

Currently, there are ~16 million organic substances.

Reasons for the diversity of organic substances.

1. Compounds of C atoms with each other and other elements of D. Mendeleev’s periodic system. In this case, chains and cycles are formed:

Straight chain Branched chain

2. Hybridization– alignment of electron clouds in shape and energy. The C atom can be in three hybrid states: sp – linear configuration, sp 2 – triangular configuration, sp 3 – tetrahedral configuration.

3. Homology- this is the existence of substances with similar properties, where each member of the homologous series differs from the previous one by a group
–CH 2 –. For example, the homologous series of saturated hydrocarbons:

4. Isomerism- this is the existence of substances that have the same qualitative and quantitative composition, but different structures.

A.M. Butlerov (1861) created a theory of the structure of organic compounds, which to this day serves as the scientific basis of organic chemistry.

Basic principles of the theory of the structure of organic compounds:

1) atoms in molecules are connected to each other by chemical bonds in accordance with their valence;

2) atoms in molecules of organic compounds are connected to each other in a certain sequence, which determines the chemical structure of the molecule;

3) the properties of organic compounds depend not only on the number and nature of their constituent atoms, but also on the chemical structure of the molecules;

4) in molecules there is a mutual influence of atoms, both connected and not directly connected to each other;

5) the chemical structure of a substance can be determined by studying its chemical transformations and, conversely, its properties can be characterized by the structure of a substance.

Let us consider some provisions of the theory of the structure of organic compounds.

what is the reason for the diversity of substances? help urgently, tomorrow is chemistry, but I can’t find the answer to this question! and got the best answer

Answer from Podsolnushki[guru]
Reasons for the diversity of organic substances: chemical structure, elemental (qualitative) composition. Examples of hydrocarbon and oxygen-containing organic compounds
Organic substances include carbon-containing substances, mainly formed in living organisms. Today, many organic substances can be obtained artificially in the laboratory. A large number of organic compounds not found in nature have been synthesized.
The total number of known organic substances exceeds 10 million, while inorganic substances are about 100 thousand. This diversity of organic compounds is associated with the ability of carbon atoms to connect in chains of varying lengths. Bonds between carbon atoms can be single or multiple: double, triple. In this case, substances can have the same molecular formula, but different structure and properties (this phenomenon is called isomerism).
Organic substances include carbon, hydrogen, oxygen, as well as nitrogen, phosphorus, and sulfur. In addition, almost any elements can be included.
Hydrocarbons are substances consisting of two elements: carbon and hydrogen.
Methane (it is also called swamp gas, mine gas, because it is formed during the decomposition of organic residues at the bottom of swamps, and is also released from coal seams in mines). Consists of one carbon atom connected by covalent bonds to four hydrogen atoms. Molecular formula CH4. The structural formula shows the order of bonding of atoms in a molecule:
H
l
H–C–H
l
H The angle between the bonds is 120º (the electron pairs forming the bond repel and are located at the maximum distance from each other).
Acetylene C2H2 contains a triple bond:
H – C ≡ C – H
An example of oxygen-containing organic substances is methyl (wood) alcohol CH3OH (systematic name methanol),
ethyl alcohol C2H5OH (ethanol),
acetic acid CH3COOH
Ready answer in class.

Reply from Yoidor Sidorov[guru]
The fact is that even under terrestrial conditions, molecules can combine in an unimaginably large number of combinations with each other. And if we take their capabilities in our not very hot Sun? Does this amount to billions of times more unimaginable? What if we take the hot suns of other galaxies? What if there are even hotter suns in other universes? A? That's it.

Reply from -=TeRNoL=-[newbie]
The reason is in different molecular chains like)

The lesson will examine types of crystal lattices, types of aggregate states of matter, and solids with a crystalline structure. The concept of polymorphism and allotropy is introduced.

I. Repetition

Repeat from the 8th grade course:

II. The variety of substances in the surrounding world

Currently, more than 100 chemical elements are known. They form more than 400 simple substances and several million of a wide variety of complex chemical compounds. What are the reasons for this diversity?

1. Isotopy of elements and their compounds

Isotopes - a variety of atoms of the same chemical element, differing from each other only in their mass.

For example, the hydrogen atom has three isotopes: 1 1 H - protium, 1 2 H (D) - deuterium and 1 3 H (T) - tritium. They and oxygen form a complex substance - water of various compositions: ordinary natural water - H 2 O, heavy water - D 2 O (contained in natural water in the ratio H: D = 6900: 1).

Isobars , atoms of different chemical elements with the same mass number A.

Isobar nuclei (in chemistry) contain an equal number of nucleons, but different numbers of protons Z and neutrons N.

For example, the atoms 4 10 Be, 5 10 B, 6 10 C represent three Isobars (in chemistry) with A = 10.

2. Allotropy

Allotropy - the phenomenon of the existence of a chemical element in the form of several simple substances (allotropic modifications or allotropic modifications).

For example, the oxygen atom occurs in the form of oxygen and ozone.

Audio Definition: “Allotropy”

Allotropy is explained by the different composition of a substance or the difference in their crystal lattice. Acid-rod and ozone are all-lo-tropic mo-di-fi-ka-tions of hi-mi-che-sko-go element-men-ta sour-lo-ro-da. Coal-le-rod forms graphite, diamond, full-le-ren, car-bin. The distribution of atoms in their crystal lattice is different, and that is why they manifest their different -stva. Phosphorus has all-tropic substances - red, white and black phosphorus. Al-lo-tro-piya ha-rak-ter-na and for metals. For example, iron can exist in the form of α, β, δ, γ.

Te-ku-honor of amorphous substances

One of the properties by which amorphous bodies are distinguished from liquid ones is their fluidity. If you put a piece of resin on a heated surface, then it will gradually spread over this surface.

Viscosity- this is the ability to resist the movement of some parts of the body from others for liquids and gases : the higher it is, the more difficult it is to change the shape of the body. Window glass is a typical amorphous substance. Theo-re-ti-che-ski, they should gradually flow down. But the viscosity of the glass is high, and its deformation can be ignored. The viscosity of glass is approximately 1000 times higher than the viscosity of resin. Over the course of a year, the deformation of glass becomes 0.001%. Over 1000 years, the deformation of glass becomes 1%.

Dependence of the state of aggregation on long- and short-range order of arrangement

Depending on the pressure and temperature, all substances can exist in different ag-res -gat-nyh with-sto-ya-ni-yah: solid, liquid, gas-based or in the form of plasma. At low temperatures and high pressure, all substances exist in a solid ag-re-gat. hundred-i-nii. Solid and liquid substances are called kon-den-si-ro-van-nym.

In solid bodies, the parts are distributed compactly, in a certain row. Depending on the degree of emphasis of particles in solids, 2 phase conditions are determined sto-i-niya: crystal-li-che-che-skoe and amorphous. If the parts are distributed in such a way that there is some kind of abutment between the neighboring parts, adequacy in race, namely: exact distance and angles between them, such a phenomenon is called close-in-a-row in the same dis-position. Rice. A.

A b

Rice. 1. Are there near and far in a row in the distribution of particles?

If the parts are distributed in such a way that the emphasis is on the blue and between close-to-si-si-mi, and at the greatest distances, this is what they call far away in a row. Rice. b.

Examples of amorphous substances

Amorphous body(from Greek A - not, morphe - form) - formless substances. In them there is only a nearby row and no further row.

Examples of amorphous bodies are shown in Fig. 2.

Rice. 2. Amorphous bodies

These are wax, glass, plasticine, resin, chocolate.

Properties of amorphous substances

• They only have a close order (as in liquids).
• Solid ag-re-gat-noe under normal conditions.
• There is no clear melting temperature. Swimming in the in-ter-va-le temp-pe-ra-tour.

Crystalline substances

IN cry-has-become-che-skom the body exists both near and far in a row. If you mentally connect the points that represent the lines, you get a spatial framework, which -ha-ha-has-become-a-grill. Points in which particles are located - ions, atoms or molecules - are called knots of crystals -che-skoy lattice (Fig. 3). The parts are not rigidly fixed at the nodes, they can move around a little without running away from these points. Depending on what parts are in the nodes of the crystal-steel lattice, you its types (Table 1).

Rice. 3. Cri-sta-che-re-shet-ka

Dependence of properties on the type of crystal lattice

Physical properties of substances with different types of crystals

Table 1. Physical properties of substances

There are several sub-types of cry-ste-che-re-she-currents, different races -eat atoms in space.

In substances with an atomic, ionic, metal-li-che-cry-steel lattice, there are no mo-le-cools - this silent substances.Molecular substances- with a mo-le-ku-lyar-cry-ste-li-grid.

Polymorphism

Polymorphism - this is a phenomenon in which complex substances of the same composition have different crystals -shet-ki.

For example, pyrite and mar-ka-site. Their shape is FeS2. But they look different, and have different physics -stva-mi. Ana-lo-gic-but, different-personal-mi-fi-zi-che-ski-mi properties-mi-la-da-yut mi-ne-ra-ly so-sta-va CaCO3: ara-go-nit, marble, Iceland spar, chalk.

Organic substances include carbon-containing substances, mainly formed in living organisms. Today, many organic substances can be obtained artificially in the laboratory. A large number of organic compounds not found in nature have been synthesized.

The total number of known organic substances exceeds 10 million, while inorganic substances are about 100 thousand. This diversity of organic compounds is associated with the ability of carbon atoms to join in chains of varying lengths. Bonds between carbon atoms can be single or multiple: double, triple. In this case, substances can have the same molecular formula, but different structure and properties (this phenomenon is called isomerism).

Organic substances include carbon, hydrogen, oxygen, as well as nitrogen, phosphorus, and sulfur. In addition, almost any elements can be included.

Hydrocarbons- substances consisting of two elements: carbon and hydrogen.

Methane (also called swamp gas, mine gas, because it is formed during the decomposition of organic residues at the bottom of swamps, and is also released from coal seams in mines). Consists of one carbon atom connected by covalent bonds to four hydrogen atoms. Molecular formula CH4. The structural formula shows the order of bonding of atoms in a molecule:
H
l
H–C–H
l
H

To correctly compose the structural formulas of organic substances, you need to remember that carbon atoms form 4 bonds, depicted by dashes (i.e., the valence of carbon by the number of bonds is equal to four. In organic chemistry, it is the valence by the number of bonds that is predominantly used).

In grades 10–11, it is studied that the methane molecule has the shape of a triangular pyramid - a tetrahedron, like the famous Egyptian pyramids.

Ethylene C 2 H 4 consists of two carbon atoms connected by a double bond:

The angle between the bonds is 120º (the electron pairs forming the bond repel and are located at the maximum distance from each other).

Acetylene C 2 H 2 contains a triple bond:
H – C ≡ C – H

As an example oxygen-containing organic substances can be called methyl (wood) alcohol CH 3 OH (systematic name methanol),

ethyl alcohol C 2 H 5 OH (ethanol),

acetic acid CH 3 COOH

(the acidic residue of acetic acid CH 3 COO - is usually at the bottom of the solubility table, so if you forget the formula, take the solubility table - it should be on the exam - and add hydrogen to the acidic residue)

Reasons for the wide variety of substances. Thanks to the existence of more than 100 types of atoms and their ability to combine with each other in different quantities and sequences, millions of substances were formed. Among them there are substances of natural origin. These are water, oxygen, oil, starch, sucrose and many others.

Thanks to advances in chemistry, it has become possible to create new substances even with predetermined properties. You also know such substances. This is polyethylene, the vast majority of medicines, artificial rubber - the main substance in the composition of rubber from which bicycle and car tires are made. Since there are so many substances, there was a need to somehow divide them into separate groups.

Substances are divided into two groups - simple and complex.

Simple substances. There are substances whose formation involves atoms of only one type, that is, one chemical element. Let's use the reference table. 4 (see p. 39) and consider examples. The simple substance aluminum is formed from the atoms of the chemical element aluminum given in it. This substance contains only aluminum atoms. Like aluminum, the simple substance iron is formed only from atoms of one chemical element - iron. Please note that the names of substances are usually written with a lowercase letter, and chemical elements with a capital letter.

Substances formed by atoms of only one chemical element are called simple.

Oxygen is also a simple substance. However, this simple substance differs from aluminum and iron in that the oxygen atoms from which it is formed are connected two at a time in one molecule. The main substance in the Sun is hydrogen. This is a simple substance whose molecules consist of two hydrogen atoms.

Simple substances contain either atoms or molecules. Molecules of simple substances formed from two or more atoms of one chemical element.

Complex substances. There are several hundred simple substances, while there are millions of complex substances. They are made up of atoms of different elements. Indeed, the molecule of the complex substance water contains hydrogen and oxygen atoms. Methane is formed by hydrogen and carbon atoms. Please note that the molecules of both substances contain hydrogen atoms. There is one oxygen atom in a water molecule, but one carbon atom in a methane molecule.

Such a small difference in the composition of molecules and such large differences in properties! Methane is a highly flammable and flammable substance; water does not burn and is used to extinguish fires.

The subsequent division of substances into groups is the division into organic and inorganic substances.

Organic substances. The name of this group of substances comes from the word organism and refers to complex substances that were first obtained from organisms.

Today, more than 10 million organic substances are known, and not all of them are of natural origin. Examples of organic substances are proteins, fats, and carbohydrates, which are rich in food products (Fig. 20).

Many organic substances were created by humans in laboratories. But the name “organic substances” itself has been preserved. Now it extends to almost all complex substances containing carbon atoms.

Organic substances are complex substances whose molecules contain carbon atoms.

Inorganic substances. The remaining complex substances that are not organic are called inorganic substances. All simple substances are classified as inorganic. Inorganic substances are carbon dioxide, baking soda and some others.

In the bodies of inanimate nature, inorganic substances predominate; in the bodies of living nature, the majority of substances are organic. In Fig. 21 depicts bodies of inanimate nature and man-made bodies. They are formed either from inorganic substances (Fig. 21, a-d), or made from organic substances of natural origin artificially created by man (Fig. 21, d-f).

One sucrose molecule consists of 12 carbon atoms, 22 hydrogen atoms, 11 oxygen atoms. The composition of its molecule is denoted by the notation C12H22O11. When burned, charring) sucrose turns black. This happens because the sucrose molecule decomposes into the simple substance carbon (which is black) and the complex substance water.

Be a conservationist

Organic substances (polyethylene) are used to make a variety of packaging materials, such as lawn water bottles, bags, and disposable tableware. They are durable, lightweight, but are not subject to destruction in nature, and therefore pollute the environment. Burning these products is especially harmful, since toxic substances are formed during their combustion.

Protect nature from such pollution - throw plastic products into the fire, collect them in specially designated areas. Advise your family and friends to use biobags and bioware, which decompose over time without harming nature.