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Biochemistry
Biochemistry is the branch of science that explores the chemical processes within and related to living organisms. It is a laboratory-based science that combines biology and chemistry, using chemical knowledge and techniques to help understand and solve biological problems.
Fundamentals of biochemistry
Biochemistry has contributed immensely to whatever modern science and technology has developed. To thoroughly understand the depth of biochemistry, one must be familiar with the basic chemical principles that form the backbone of biological molecules and processes.
Elements of life
Life as we know it consists primarily of six elements: carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S). These elements combine to form small molecules and larger molecules that are essential for life.
An example of a simple molecule is water (H2O
), which is essential to all living organisms due to its unique properties such as solvation capacity, high heat capacity, and surface tension.
Macromolecules
Macromolecules are large, complex molecules that are important for biological processes. These include carbohydrates, proteins, lipids, and nucleic acids.
These macromolecules are essential for living organisms:
- Carbohydrates: These are composed of carbon, hydrogen, and oxygen. A common example is glucose (
C6H12O6
), which is the primary energy source for cells. - Proteins: Made up of amino acids, proteins perform a variety of functions, including catalyzing metabolic reactions, replicating DNA, and transporting molecules. An enzyme such as amylase is an example of a protein that helps digest carbohydrates.
- Lipids: These are nonpolar molecules that are hydrophobic. They are important for energy storage and forming cell membranes (e.g., phospholipids).
- Nucleic Acids: DNA and RNA are nucleic acids that store and transfer genetic information.
Biochemical processes
Biochemical processes occur within living organisms and are essential to maintaining life. These include metabolism, enzymatic activity, and cellular respiration.
Metabolism
Metabolism refers to all the chemical reactions that occur within a living organism to maintain life. It includes catabolic and anabolic pathways that break down molecules and build molecules for energy, respectively. For example, glucose is broken down in the presence of oxygen to produce energy. This process is known as cellular respiration and can be represented by the following reaction:
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy (ATP)
Enzymes
Enzymes are proteins that act as catalysts to speed up biochemical reactions without being consumed in the process. They lower the activation energy, making reactions occur more easily. A visual representation can summarize the energy flow:
Enzymatic activity is important in biological functions, such as digestion, where enzymes such as trypsin help break down proteins.
Central dogma of molecular biology
The central tenet of molecular biology is a framework for understanding the flow of genetic information. This is the process through which DNA is transcribed into RNA, which is then translated into proteins.
DNA → RNA → Protein
This flow of information is vital for the synthesis of proteins, which perform most of the functions in living cells, from providing structural support to acting as hormones.
Conclusion
Biochemistry is an interdisciplinary field that combines principles of both biology and chemistry to understand life at the molecular level. Understanding biochemistry is essential to understanding how living things work, from the smallest microorganisms to the largest ecosystems. The study of macromolecules, enzymatic processes, and the central tenet of molecular biology exemplify the complexity and beauty of biochemical processes.