Biological molecules Your name | Teacher’s name | School Introduction • Biological molecules are the foundation of life, playing crucial roles in various biological processes. • These molecules are essential building blocks found in all living organisms. • This presentation explores the four major types of biological molecules: carbohydrates, lipids, proteins, and nucleic acids. Overview of Biological Molecules • Biological molecules are diverse and serve unique functions within living organisms. • Carbohydrates, lipids, proteins, and nucleic acids are the four major types. • Understanding these molecules is vital for comprehending the complexities of life processes. •Carbohydrates • Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen. • They serve as a primary source of energy for organisms. • Monosaccharides, disaccharides, and polysaccharides are the three types of carbohydrates. • Examples include glucose, fructose, sucrose, and Types of Carbohydrates Monosaccharides Disaccharides Polysaccharides • Monosaccharides are the simplest form of carbohydrates and are often referred to as simple sugars. • They consist of a single sugar unit and have the general molecular formula (CH2O)n, where "n" represents the number of carbon atoms in the molecule. • Monosaccharides can exist as linear chains or form ring structures in aqueous solutions. • Disaccharides are a type of carbohydrate composed of two monosaccharide units joined together through a glycosidic bond. • The glycosidic bond forms through a dehydration synthesis reaction, where a water molecule is eliminated. • Common examples of disaccharides include sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose). • Polysaccharides serve as both energy storage molecules and provide structural support in organisms. • Glycogen, found in animals, and starch, found in plants, are examples of polysaccharides used for energy storage. • They are composed of many glucose units linked together in a branched or linear arrangement. • When energy is needed, these molecules can be broken down into individual glucose units for metabolism. • Cellulose is a polysaccharide found in the cell walls of plants, providing structural support and rigidity. Lipids • Lipids are diverse organic compounds insoluble in water but soluble in nonpolar solvents. • They have various functions, including long-term energy storage, insulation, and structural components of cell membranes. • Types of lipids include triglycerides, phospholipids, and steroids. • Examples of lipids are olive oil, butter, and cholesterol. Types of Lipids Tringlycerides (fats) Phospholipids • Energy Storage: Triglycerides serve as a major form of energy storage in organisms. They are highly efficient in storing energy because they have a high energy content per gram compared to other biological molecules. • Structure and Insulation: Triglycerides also play a crucial role in providing structural support and insulation. • Phospholipids are a key structural component of cell membranes. • They form a lipid bilayer, with hydrophilic (water-loving) phosphate heads facing outward and hydrophobic (water-repelling) fatty acid tails facing inward. • This arrangement provides a barrier that regulates the movement of substances in and out of cells. • The fluidity of the phospholipid bilayer allows for flexibility and essential functions like membrane fusion and cell signaling. Steroids • Steroids are a type of lipid characterized by a specific structure, including four interconnected carbon rings. • Steroids play a crucial role in various physiological processes in the body, acting as signaling molecules and regulators. • One of the primary functions of steroids is their involvement in hormone regulation. • Steroid hormones, such as cortisol, estrogen, and testosterone, are produced in various glands and help regulate metabolism, development, reproduction, and stress response. • They exert their effects by binding to specific receptors in target cells, triggering a cascade of cellular responses. Proteins • Proteins are large, complex macromolecules composed of amino acids. • They have diverse functions, including enzyme catalysis, structural support, immune response, and cell signaling. • Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. • Examples of proteins are enzymes, antibodies, and collagen. Nucleic Acids • Nucleic acids are macromolecules that store and transmit genetic information. • DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are the two main types. • DNA carries hereditary information, while RNA is involved in protein synthesis. • Nucleic acids are essential for the growth, development, and functioning of all living organisms. Biochemical Reactions • Biological molecules participate in biochemical reactions. • Dehydration synthesis (condensation) and hydrolysis are two important reactions. • Dehydration synthesis links monomers to form polymers, while hydrolysis breaks polymers into monomers. • These reactions play a vital role in metabolism and the synthesis of complex molecules. Examples of Biological Molecules in Action • Carbohydrates provide energy for daily activities and cellular processes. • Lipids store energy, cushion organs, and act as structural components. • Proteins facilitate chemical reactions, transport molecules, and provide structural support. • Nucleic acids store and transmit genetic information for inheritance and protein synthesis. Synthesis of Biomolecules • Cells are capable of synthesizing a wide range of biomolecules, including proteins, carbohydrates, lipids, and nucleic acids. • Protein synthesis occurs through a process called translation, where ribosomes translate the genetic information encoded in mRNA into a specific sequence of amino acids to form proteins. • Carbohydrate synthesis involves the production of glucose, the primary energy source for cells, through processes like photosynthesis in plants and gluconeogenesis in animals. • Lipid synthesis occurs in cellular compartments called the endoplasmic reticulum and the Golgi apparatus, where various enzymes and pathways are involved in the production of different types of lipids. • Nucleic acids, such as DNA and RNA, are synthesized through replication and transcription processes, respectively, using existing nucleotides as building blocks. Conversion of Molecules and Energy • Cells have metabolic pathways that enable the conversion of molecules and energy to support various cellular functions. • Cellular respiration is a key metabolic process that converts glucose and other organic molecules into energyrich molecules called ATP (adenosine triphosphate) through a series of biochemical reactions. Conclusion • Biological molecules are fundamental to life processes and exhibit remarkable diversity. • Carbohydrates, lipids, proteins, and nucleic acids each have unique functions. • Understanding these molecules helps unravel the complexities of living organisms. • The study of biological molecules is essential for advancements in medicine, agriculture, and biotechnology.
