Organic biomolecules are chemical compounds present in living beings that perform essential functions for the maintenance of life. They are composed primarily of carbon, hydrogen, oxygen, and nitrogen, and may also contain phosphorus, sulfur, and other elements. These molecules fall into four main categories: carbohydrates, lipids, proteins, and nucleic acids. Each has specific characteristics and performs vital functions for the functioning of organisms. Some examples of organic biomolecules include glucose, fatty acids, enzymes, and DNA. By understanding the structure and function of these molecules, we can better understand the biological processes that occur in living beings.
Main characteristics of biomolecules: learn about the fundamental properties of these compounds essential for life.
Biomolecules are organic compounds essential to life, present in all living beings. They perform several vital functions, including structural, energetic, and catalytic functions, among others. Understanding the main characteristics of these molecules is essential to understanding the complexity of biological processes.
One of the main characteristics of biomolecules is their structural complexity. They are composed of atoms of carbon, hydrogen, oxygen, nitrogen, and, in some cases, phosphorus and sulfur. These elements are organized in specific ways, forming molecules with different shapes and functions.
Furthermore, biomolecules have different levels of organization. They can be classified into four main groups: carbohydrates, lipids, proteins, and nucleic acids. Each group performs specific functions in the organism and is essential for maintaining life.
Another important characteristic of biomolecules is their ability to interact. They can bond with each other and form more complex structures, such as cell membranes, organelles, and tissues. These interactions are essential for the proper functioning of organisms.
Finally, biomolecules are highly reactive and participate in various chemical reactions in the body. They can be broken down and synthesized to provide energy, build cellular structures, and perform various other vital functions.
In short, biomolecules are organic compounds essential to life, featuring structural complexity, varying levels of organization, a capacity for interaction, and high reactivity. Understanding these characteristics is crucial to understanding the importance of these compounds in sustaining life.
Importance of biomolecules: learn about their essential functions for the human body.
Biomolecules are organic molecules present in living beings and perform essential functions for the human body. They are fundamental to the maintenance of life, as they are involved in various metabolic and structural processes that ensure the proper functioning of the body.
The main organic biomolecules found in our bodies include carbohydrates, proteins, lipids, and nucleic acids. Each of these has specific functions that are essential for our survival.
Os carbohydrates, for example, are the main source of energy for cells and also play an important structural role in some cellular structures. proteins are responsible for the formation of tissues, transport of substances and the functioning of enzymes. lipids act in energy reserves, thermal insulation and the formation of cell membranes. Finally, nucleic acids are essential for the storage and transmission of genetic information.
In addition to these biomolecules, there are also other organic substances such as vitamins and hormones, which perform regulatory functions in the body. All of these molecules work together to ensure the balance and health of our bodies.
Therefore, understanding the importance of biomolecules is fundamental to understanding how our bodies function and how we can maintain our health. A balanced, nutrient-rich diet is essential to ensure adequate intake of these substances essential for our survival.
Learn about the four main groups of biomolecules present in living beings.
Organic biomolecules are complex molecules essential to the life of living beings. They perform vital functions in the organism, such as providing energy, forming cellular structures, and regulating metabolic processes. There are four main groups of biomolecules present in living beings: carbohydrates, proteins, lipids e nucleic acids.
Os carbohydrates They are the main source of energy for cells and are present in foods such as bread, pasta, and fruit. They are composed of carbon, hydrogen, and oxygen and can be classified as monosaccharides, disaccharides, and polysaccharides.
As proteins are essential for the structure and function of cells. They are composed of amino acids and perform various functions in the body, such as transporting substances, immune defense, and muscle contraction.
Os lipids are molecules that play an important role in the structure of cell membranes and in energy storage. They include substances such as fats, oils, and phospholipids.
Os nucleic acids are responsible for the storage and transmission of genetic information. They are composed of nucleotides and are present in DNA and RNA, which are essential for protein synthesis and cell replication.
In short, organic biomolecules are fundamental to the life of living beings, playing vital roles in various biological processes. It's important to maintain a balanced diet to ensure adequate intake of these biomolecules and maintain the body's health.
The relevance of organic biomolecules in sustaining human life.
Organic biomolecules play a fundamental role in sustaining human life, being essential for the proper functioning of the organism. These molecules are composed of carbon and other elements such as hydrogen, oxygen, nitrogen, phosphorus, and sulfur, and are present in all known life forms.
The main organic biomolecules are carbohydrates, lipids, proteins, and nucleic acids. Each of these classes of compounds has specific functions in the body, contributing to various vital activities.
Os carbohydrates are the main source of energy for cells, providing the glucose necessary for cellular metabolism. lipids play important roles in the structure of cell membranes, energy storage and hormone production.
As proteins, in turn, are essential molecules for the construction and maintenance of body tissues, acting as enzymes, transporters of substances, and components of the immune system. Finally, nucleic acids, such as DNA and RNA, are responsible for the transmission and expression of genes, being fundamental for heredity and protein synthesis.
Thus, organic biomolecules perform vital functions in the human body, ensuring the maintenance of life and the proper functioning of all bodily systems. Maintaining a balanced, nutrient-rich diet is essential to ensure the integrity and proper functioning of biomolecules and, consequently, the individual's health and well-being.
Organic biomolecules: characteristics, functions and examples
As organic biomolecules Found in all living beings, they are characterized by a carbon-based structure. Compared to inorganic molecules, organic molecules are much more complex in terms of structure. Furthermore, they are much more varied.
They are classified as proteins, carbohydrates, lipids, and nucleic acids. Their functions are extremely varied. Proteins participate as structural, functional, and catalytic elements. Carbohydrates also have structural functions and are the primary source of energy for organic beings.
Lipids are important components of biological membranes and other substances, such as hormones. They also function as energy storage elements. Finally, nucleic acids—DNA and RNA—contain all the information necessary for the development and maintenance of living beings.
General features
One of the most important characteristics of organic biomolecules is their versatility in forming structures. This enormous diversity of organic variants that can exist is due to the privileged position provided by the carbon atom at the center of the second period.
The carbon atom has four electrons in its highest energy level. Thanks to its average electronegativity, it is capable of forming bonds with other carbon atoms, forming chains of different shapes and lengths, open or closed, with single, double, or triple bonds within.
Likewise, the average electronegativity of the carbon atom allows it to form bonds with atoms other than carbon, such as electropositive (hydrogen) or electronegative (oxygen, nitrogen, sulfur, among others).
This bonding property allows carbon atoms to be classified as primary, secondary, tertiary, or quaternary, depending on the number of carbons to which they are bonded. This classification system is independent of the number of valences involved in the bond.
Classification and functions
Organic molecules are classified into four major groups: proteins, carbohydrates, lipids, and nucleic acids. We'll describe them in detail below:
-Proteins
Proteins constitute the group of organic molecules best defined and characterized by biologists. This extensive knowledge is primarily due to their intrinsic ease of isolation and characterization—compared to the other three organic molecules.
Proteins play a wide range of biological roles. They can serve as transport, structural, and even catalytic molecules. The latter group is composed of enzymes.
Structural building blocks: amino acids
The building blocks of proteins are amino acids. In nature, we find 20 types of amino acids, each with its own well-defined physicochemical properties.
These molecules are classified as alpha-amino acids because they have a primary amino group and a carboxylic acid group as substituents on the same carbon atom. The only exception to this rule is the amino acid proline, which is classified as an alpha-amino acid due to the presence of a secondary amino group.
To form proteins, these "building blocks" must polymerize, and they do so by forming a peptide bond. The formation of a protein chain involves the elimination of a water molecule per peptide bond. This bond is represented as CO-NH.
In addition to being part of proteins, some amino acids are considered energy metabolites and many of them are essential nutritional elements.
Properties of amino acids
Each amino acid has its own mass and average appearance in proteins. Furthermore, each has a pK value for the alpha-carboxylic acid, alpha-amino groups, and side group.
The pK values of the carboxylic acid groups are about 2,2; while the alpha-amino groups have pK values close to 9,4. This characteristic leads to a typical structural feature of amino acids: at physiological pH, both groups are in the form of an ion.
When a molecule carries oppositely charged groups, they are called dipole ions or zwitterions. Therefore, an amino acid can act as either an acid or a base.
Most alpha amino acids have melting points near 300°C. They dissolve more readily in polar environments than in nonpolar solvents. Most are quite soluble in water.
Protein structure
To specify the function of a specific protein, it is necessary to determine its structure—that is, the three-dimensional relationship between the atoms that make up the protein in question. Four levels of structural organization have been determined for proteins:
Primary structure : refers to the sequence of amino acids that form the protein, excluding any conformation that its side chains may support.
Secondary structure : is formed by the local spatial arrangement of the backbone atoms. Again, the conformation of the side chains is not taken into account.
Tertiary structure : refers to the three-dimensional structure of the entire protein. While it can be difficult to establish a clear division between tertiary and secondary structure, defined conformations (such as the presence of helices, folded blades, and turns) are used to uniquely designate secondary structures.
Quaternary structure : applied to proteins composed of multiple subunits, that is, two or more individual polypeptide chains. These units can interact through covalent forces or disulfide bonds. The spatial arrangement of the subunits determines the quaternary structure.
-Carbohydrates
Carbohydrates, carbohydrates or saccharides (from the Greek roots sakcharón, meaning sugar) are the most abundant class of organic molecules on planet Earth.
Their structure can be inferred from the name “carbohydrates”, as they are molecules with the formula (CH 2 O) n Where n is greater than 3.
Carbohydrates have varied functions. One of the main ones is structural, especially in plants. In the plant kingdom, cellulose is the main structural material, accounting for 80% of the body's dry weight.
Another important function is its energy role. Polysaccharides, such as starch and glycogen, are important sources of nutrient reserves.
Classification
The basic units of carbohydrates are monosaccharides, or simple sugars. These are derived from straight-chain aldehydes or ketones and polyhydric alcohols.
They are classified according to the chemical nature of their carbonyl group into aldoses and ketoses. They are also classified according to the number of carbons.
Monosaccharides group together to form oligosaccharides, often found in association with other types of organic molecules, such as proteins and lipids. These are classified as homopolysaccharides or heteropolysaccharides, depending on whether they are composed of the same monosaccharides (the former) or different.
Furthermore, they are also classified according to the nature of the monosaccharide that composes them. Glucans are polymers of glucose, galactose polymers are galactans, and so on.
Polysaccharides have the particularity of forming linear and branched chains, since glycosidic bonds can be formed with any of the hydroxyl groups found in the monosaccharide.
When a greater number of monosaccharide units are associated, we speak of polysaccharides.
-Lipids
Lipids (from the Greek lipos, meaning fat) are organic molecules that are insoluble in water and soluble in inorganic solvents, such as chloroform. These constitute fats, oils, vitamins, hormones, and biological membranes.
Classification
Fatty acids : are carboxylic acids with hydrocarbon chains of considerable length. Physiologically, it is rare to find them free, as in most cases they are esterified.
In animals and plants, we often find them in their unsaturated form (forming double bonds between carbons) and polyunsaturated (with two or more double bonds).
Triacylglycerols : Also called triglycerides or neutral fats, they make up the majority of fats and oils found in animals and plants. Their main function is to store energy in animals, which have specialized cells for storage.
They are classified according to the identity and position of the fatty acid residues. Vegetable oils are generally liquid at room temperature and are richer in fatty acid residues with double and triple bonds between their carbon atoms.
On the other hand, animal fats are solid at room temperature and the number of unsaturated carbons is low.
Glycerophospholipids : also known as phosphoglycerides, they are the main components of lipid membranes.
Glycerophospholipids have a nonpolar, or hydrophobic, "tail" and a polar, or hydrophilic, "head." These structures are grouped into a bilayer, with the tails pointing inward, to form membranes. Within these membranes, a series of proteins are incorporated.
Sphingolipids : are lipids found in very low quantities. They are also part of membranes and are derived from sphingosine, dihydrosphingosine, and their counterparts.
Cholesterol : In animals, it is a predominant component of membranes, modifying their properties, such as fluidity. It is also found in the membranes of cellular organelles. It is an important precursor of steroid hormones, involved in sexual development.
-Nucleic acids
Nucleic acids are DNA and the different types of RNA that exist. DNA is responsible for storing all genetic information, which enables the development, growth, and maintenance of living organisms.
RNA, on the other hand, participates in the transfer of genetic information encoded in DNA to protein molecules. Classically, three types of RNA are distinguished: messenger, transfer, and ribosomal. However, several small RNAs have regulatory functions.
Structural building blocks: nucleotides
The building blocks of nucleic acids, DNA and RNA, are nucleotides. Chemically, they are pentose phosphate esters, in which a nitrogenous base is attached to the first carbon. We can distinguish between ribonucleotides and deoxyribonucleotides.
These molecules are planar, aromatic, and heterocyclic. When the phosphate group is absent, the nucleotide is renamed a nucleoside.
In addition to their role as monomers in nucleic acids, these molecules are biologically ubiquitous and participate in a significant number of processes.
Nucleoside triphosphates are energy-rich products, like ATP, and are used as the energy currency for cellular reactions. They are an important component of the coenzymes NAD. + , NADP + , FMN, FAD and coenzyme A. Finally, they are regulatory elements of different metabolic pathways.
Examples
There are countless examples of organic molecules. The most prominent and studied by biochemists are discussed below:
Hemoglobin
Hemoglobin, the red pigment in blood, is a classic example of a protein. Thanks to its widespread distribution and easy isolation, it has been studied since ancient times.
It is a protein composed of four subunits and, therefore, falls into the tetrameric classification, with two alpha and two beta units. Hemoglobin subunits are related to a small protein responsible for oxygen uptake in muscles: myoglobin.
The heme group is a porphyrin derivative. This characterizes hemoglobin and is the same group found in cytochromes. The heme group is responsible for the characteristic red color of blood and is the physical region where each globin monomer binds to oxygen.
The main function of this protein is to transport oxygen from the organ responsible for gas exchange – called lungs, gills or skin – to the capillaries, to be used in respiration.
Cellulose
Cellulose is a linear polymer composed of D-glucose subunits linked by beta 1,4 linkages. Like most polysaccharides, they have no maximum size limit. However, they average about 15.000 glucose residues.
It's the component of plant cell walls. Thanks to cellulose, they are rigid and allow them to cope with osmotic stress. Similarly, in larger plants, such as trees, cellulose provides support and stability.
Although predominantly related to plants, some animals called tunicates have cellulose in their structure.
It is estimated that an average of 10 to 15 kg of cellulose is synthesized – and degraded – per year.
Biological membranes
Biological membranes are composed primarily of two biomolecules: lipids and proteins. The spatial conformation of lipids is bilayer-shaped, with hydrophobic tails pointing inward and hydrophilic heads pointing outward.
The membrane is a dynamic entity and its components undergo frequent movements.
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