Biochemistry: A Study of Chemical Processes in Living Organisms PDF

Department University of Guelma Department of life and Natural Science Level: 2 nd year SNV (LMD) Miss : Chekakta Mahassine **Biochemistry** **Definition :** study of the chemical substances and processes that occur in [plants](https://www.britannica.com/plant/plant), [animals](https://www.brita...

Department University of Guelma Department of life and Natural Science Level: 2 nd year SNV (LMD) Miss : Chekakta Mahassine **Biochemistry** **Definition :** study of the chemical substances and processes that occur in [plants](https://www.britannica.com/plant/plant), [animals](https://www.britannica.com/animal/animal), and microorganisms and of the changes they undergo during development and life. It deals with the chemistry of life, and as such it draws on the techniques of [[analytical]](https://www.merriam-webster.com/dictionary/analytical), organic, and [physical chemistry](https://www.britannica.com/science/physical-chemistry), as well as those of physiologists concerned with the molecular basis of vital processes. All chemical changes within the organism---either the [[degradation]](https://www.merriam-webster.com/dictionary/degradation) of substances, generally to gain necessary energy, or the buildup of complex molecules necessary for life processes---are collectively called [metabolism](https://www.britannica.com/science/metabolism). These chemical changes depend on the action of organic [[catalysts]](https://www.merriam-webster.com/dictionary/catalysts) known as [enzymes](https://www.britannica.com/science/enzyme), and enzymes, in turn, depend for their existence on the genetic apparatus of the [cell](https://www.britannica.com/science/cell-biology). It is not surprising, therefore, that biochemistry enters into the investigation of chemical changes in [disease](https://www.britannica.com/science/disease), drug action, and other aspects of [medicine](https://www.britannica.com/science/medicine), as well as in [nutrition](https://www.britannica.com/science/nutrition), [genetics](https://www.britannica.com/science/genetics), and agriculture. The term *biochemistry* is synonymous with two somewhat older terms: *physiological chemistry* and *biological chemistry*. Those aspects of biochemistry that deal with the chemistry and function of very large molecules (e.g., [proteins](https://www.britannica.com/science/protein) and [nucleic acids](https://www.britannica.com/science/nucleic-acid)) are often grouped under the term [*molecular biology*](https://www.britannica.com/science/molecular-biology). Biochemistry is a young [science](https://www.britannica.com/science/science), having been known under that term only since about 1900. Its origins, however, can be traced much further back; its early history is part of the early history of both [physiology](https://www.britannica.com/science/physiology) and [chemistry](https://www.britannica.com/science/chemistry) . Primary Branches of Biochemistry : ---------------------------------- Like other subjects, biochemistry is a vast field of study covering hundreds of living organisms, including human blood tests, body functions, diet, growth of plants, genetic systems, DNA, RNA, cell functions, generation, etc. Generally, biochemistry is known for examining the structure & chemical functions of living things, but in detail, it is divided into different branches: - Immunology - Animal Biochemistry - Enzymology - Plant Biochemistry - Cell Biology - Metabolism - Molecular Biology - Genetics ### Immunology The study of the immune system in a living organism is called immunology. This branch holds great importance for living beings as it covers the defense mechanisms. You can observe your immune system protecting your body from numerous diseases and fighting against deadly [[infections]](https://www.biomadam.com/infection-vs-disease). Moreover, a robust immune system can help a body repel HIV, cancer, malaria, dengue, and others. Therefore, a person suffering from immune or auto-immune disorders should immediately seek an immunology doctor. Humans with the most muscular immune system have high survival rate chances. Therefore, if any external microorganism/germ attacks that body, it fights against them. These invaders are usually bacteria, viruses, or other harmful particles. During this entire procedure, the defensive body molecules will either die or kill the germs, depending upon the strength of your immune system. One can strengthen his immunity through healthy foods, medication, and physical exercises. To check the strength of your immune system, simple blood tests, antigen tests, or antibody tests are performed. ### Animal Biochemistry The relationship of animals with the environment is essential for animal studies. Animal biochemistry studies the chemical compositions and chemical reactions occurring in an animal body. It covers animals' metabolism study, diseases, cell functioning, and further generations. The famous "cloning" process also falls under the study of animal biochemistry as the first animal (sheep) named Dolly was successfully cloned in 1995. ### Enzymology The study of enzymes is called enzymology. It discusses the kinetics, structure as well as functions of the enzymes. These molecules are responsible for controlling the rate of reaction. All [[enzymes are proteins]](https://www.biomadam.com/enzyme-vs-protein) that act on substrates to convert them to the required products. Enzymes are specific & increase the rate of reaction by lowering the activation energy. **Always remember that enzymes can only control the speed of response but are never involved in it.** Enzymes are generally classified into six major categories under enzymology, which can also be reused. A type of enzyme used for a single reaction cannot work for other reactions of different chemistry. For example, an enzyme working for two distinct mechanisms will always have the same reactants and similar catalysts. As soon as the catalyst changes, the enzyme will also change. ### Plant Biochemistry This branch of biochemistry deals with the structures, functions, and chemical reactions of all plants. If we go into the depths of plant biochemistry, it studies the plant energy system, defense system, its cycles, light and dark reactions, etc. All plants are living bodies that follow photosynthesis to prepare their food. This unique process uses light energy from the sun and converts it into chemical energy to obtain food, and the cycle continues! The sunlight helps plants prepare carbon dioxide and water from glucose. ### Cell Biology A cell is the fundamental unit of life. Cell biology is that branch of biochemistry that deals with the structure and functioning of cells. We are concerned with the life cycle, physiological properties, and signaling pathways under cell biology. One of the primary functions of a cell is to maintain essential processes like the Krebs's Cycle, Citric Acid Cycle, etc. Considering a cell's structure, it consists of a cell wall that surrounds and protects its cytoplasm. The cytoplasm contains all crucial organelles, such as [[mitochondria]](https://www.biomadam.com/facts-about-mitochondria), Golgi Bodies, vacuoles, ribosomes, smooth and rough endoplasmic reticulum (SER & RER), and much more. A human and a plant cell have some typical organelles, but there are differences its cell structure. For example, a human cell contains a well-defined nucleus, [[cell or plasma membrane]](https://www.biomadam.com/cell-membrance-vs-plasma-membrance), and other organelles, whereas a prominent cell wall in plant cells is added. A cell holds significant importance in one's life. Moreover, all organisms are divided into [[eukaryotes or prokaryotes]](https://www.biomadam.com/eukaryotes-vs-prokaryotes), depending upon their cells. Hence, cell biology is a vast branch of biochemistry to study! ### Metabolism The primary purpose of metabolism is to convert food into energy to run the chemical procedure in a body. All chemical reactions involved in maintaining life in a living organism are called metabolism. Metabolism is studied under biochemistry which is further divided into two categories: #### Catabolism and Anabolism These two types either make or break the molecules, so let's check out their definitions: **Catabolism** is the breakdown of larger molecules into smaller ones to release energy. These small units oxidize to be used as energy or are utilized in anabolic reactions. *For example, Amino acids from proteins, glycogen becoming glucose, and TAG becoming fatty acids.* **Anabolism **is another type of metabolic process. We usually study the building of cell components and their operations in anabolism that is stored as energy. In other words, a body requires various molecules, and their formation is termed anabolism. *For example, Bone growth, polypeptide chain, mineralization, and gluconeogenesis.* ### Molecular Biology This branch of biochemistry deals with the structure and function of macromolecules that are essential to life, such as proteins and nucleic acid. Molecular biology is the study on a molecular level, including the configuration, function, and makeup of biologically important molecules such as DNA, RNA, and proteins. Thus, molecular biology involves many other areas of biology, such as biochemistry and genetics.  The central dogma is an introductory study of molecular biology. Two steps are involved in central dogma that is transcription and translation. First, it gives information about how gene flows into protein. RNA synthesis is called transcription, whereas translation is the formation of protein from RNA. Molecular biology covers numerous techniques, including [[Polymerase Chain Reaction (PCR]](https://www.biomadam.com/what-is-polymerase-chain-reaction-pcr)), cloning, Southern blotting, northern blotting, western blotting, eastern blotting, gel electrophoresis, microarrays, etc. ### Genetics Genetics is the study of genes, variation, and heredity information of living organisms. Also, it studies the transformation of genes from parents to offspring. Heredity means the physical and mental characteristics of an individual passing from one generation to another. For example, genetics studies the height genes of a child. If a child has a tall height, there are more chances of his father or mother being heightened. Similarly, the brown eyes of an individual are because of his parents having brown eyes. A child takes almost all of his genes from his parents or one of them. Children own some physical factors, like hair, skin color, eye color, height, etc., but genetic diseases like diabetes, anemia, high blood pressure, and many others are also discussed under genetics. These diseases usually pass from generation to generation. Secondary Branches of Biochemistry ---------------------------------- Most of the secondary biochemistry branches relate to medical biochemistry. So let's have a glance at them as well: ### Blood Biochemistry We study the structure and functioning of blood in living organisms in blood biochemistry. Blood is an essential fluid that transports oxygen into the body and excretes carbon dioxide---blood primarily takes oxygen to heart and all other parts of the body. Besides being a fluid, blood also acts as tissue. A living entity cannot accept foreign particles in the body, especially those that cause damage. Leukocytes are white blood cells, acting as the defense system and fighting against infections. The production point is bone marrow and circulates in the blood---white blood cells fight against invaders. Lymphocytes, granulocytes, and monocytes are important white blood cells that collectively make a body's defense system. For instance, the lymphocytes produce antibodies against the antigens. ### Medical Biochemistry It is a primary branch of medicine that involves biochemistry in several human metabolic reactions and their diseases. It usually applies clinical biochemistry to deal with different areas of medicine. Most people choose medical biochemistry as their profession. Why is Biochemistry Important? ------------------------------ Biochemistry is a wild field to study in the research area, medical field, agriculture, and many such careers. We have already discussed that biochemistry is the combination of chemistry and biology. So, let's suppose the use of biochemistry in an agriculture field; will help you control diseases in areas like the wheat field and rice field. In pesticides and relevant diseases, most biochemical substances are used to help control such damages. Biochemistry used in medical sciences allows students to understand how chemical procedures occur, such as the citric acid cycle, Krebs cycle, and many more that happens in a body. Suppose you clutch the importance of biochemistry in the research area, genes, functions, protein formation, disease control by genetic engineering, [[RNA and DNA]](https://www.biomadam.com/how-is-dna-different-from-rna) study, etc. In that case, all are the focal points in it. Talking about the significance of biochemistry in laboratories helps diagnose many diseases like HBV, HCV, and numerous others through tests performed. Hence, it is essential in almost every field of science. A biochemist can choose any career of his choice, being a broad field. For example, he can opt to be a teacher, a forensic scientist, a lab technologist, a researcher, or other in scientific areas where biochemistry is used.