Lesson 6 Biological Molecules

BIOLOGICAL (BIOMOLECULES) Structure and Function of Biological Molecules  Objectives After going through this module, you are expected to: 1.Categorize the biological molecule as a carbohydrate or lipid according to their structure and function; 2.Explain the role of each biological molecule i...

BIOLOGICAL (BIOMOLECULES) Structure and Function of Biological Molecules  Objectives After going through this module, you are expected to: 1.Categorize the biological molecule as a carbohydrate or lipid according to their structure and function; 2.Explain the role of each biological molecule in specific metabolic processes; and 3.Detect the presence of carbohydrates and lipids in food products using simple tests.  THE CHEMISTRY OF LIFE Living organisms are primarily made up of organic compounds. The process of building organic molecules by living organisms is called biosynthesis. Biomolecules (also known as ‘’macromolecules) are organic compounds that make up all living organisms. They are all produced through the process of biosynthesis.  Monomers and Polymers Majority of biological macromolecules are polymers and are made of covalently linked basic units called monomers. Monomers that link with other monomers in various combinations result in the formation of polymers, which have different structures and functions.  FOUR MACROMOLECULES The main classes of biomolecules are carbohydrates, proteins, lipids, and nucleic acids.  FOUR MACROMOLECULES Carbohydrates are made of C, H and O (‘carbo’ – contains carbon; ‘hydrate’ – contains H and O) ‘’major cellular contents’’ Carbohydrates are one of the most abundant macromolecules on Earth. Literally, the term means “hydrates of carbons” because of its ratio of carbon, hydrogen, and oxygen.  Carbohydrates are composed of carbon and hydrate. They are classified as simple or complex sugars.  Simple sugars are monosaccharides and disaccharides  Complex sugars are polysaccharides Carbohydrates serve as primary source of energy for man, storage of energy (glycogen), structural support for cell (cellulose & chitin), food (starch). Simple and Complex Carbohydrates  FOUR MACROMOLECULES Lipids are a large group of substances also found in living systems. They are insoluble in water but are soluble in solvents that are nonpolar or have low polarity. Lipids have three major functions: 1. energy storage, especially in animal systems (Triglycerides) 2. structural, as part of cellular membranes (Phospholipids ) 3. as chemical messengers that deliver signals from one part of the body to another (Steroids)  FOUR MACROMOLECULES There are several types of lipids based on their structure but you would be more familiar with fats and oils, also known as triglycerides, or simply, “fats”.  FOUR MACROMOLECULES Fatty acids that make up fats are either saturated or unsaturated. “Saturation/Unsaturation” of fats indicates the presence or absence of double bonds in the fatty acid chain.  Unsaturated fats have at least one pair of double-bonded carbons, are liquid at room temperature, and are commonly extracted from plants.  Saturated fats do not have double-bonded hydrocarbons, are solid even at room temperature, and present in animal fats. You may also have heard about trans fats. ‘’Major component of cell membranes’’  FOUR MACROMOLECULES Proteins are some of the most complex macromolecules in terms of structure and function. The building blocks of proteins are the amino acids of which 20 are known. An amino acid has an amino group, a carboxylic group, and an R group or side chain.  Proteins Proteins are polymers of amino acids arranged in a linear sequence of amino acid which is also consist of a central carbon atom (alpha) attached to an amino acid group, a carboxyl group, hydrogen atom and variable component known as side chain. Proteins are classified based on their function. 1. Keratin in the hair is an example of a structural protein. 2. Hormones like insulin are regulatory proteins. 3. Actin and myosin proteins are for movement, and are called contractile proteins. 4. Antibodies that are produced by the white blood cells are called protective proteins. 5. Hemoglobin which carries oxygen gas is an example of a transport protein. 6. Egg albumin is a storage protein that serves as nourishment for the developing embryo.  FOUR MACROMOLECULES Nucleic acids are the most important biomolecules in the continuity of life. Nucleic acids are made up of nucleotides. Nucleotides have three components: pentose sugar (5-carbon sugar), phosphate group, and nitrogenous base.  Nucleic Acid Nucleic acids are biological macromolecules vital in the continuity of life. Nucleic acid carries the genetic material of a cell and provides instructions for the functioning of the cell. Two main types of nucleic acids deoxyribonucleic acid (DNA) ribonucleic acid (RNA). DNA carries genetic material found in all living organisms. Features of DNA and RNA DNA and RNA STRUCTURES  Enzymes Various biological molecules are needed for reactions in the body (DNA, Protein synthesis, Cellular respiration, etc.) Enzymes are the biological substances (proteins) that act as catalysts and help complex reactions everywhere in life. Enzymes A catalyst is a substance that increases the rate of chemical reaction by reducing the amount of energy needed to start that reaction. This is called the lowering of activation energy. Enzymes Activation energy can be thought of as a hill that must be gotten over. When a catalyst acts, it lowers the energy required to get over the hill and the reaction can proceed. An enzyme is an organic catalyst meaning that it is a protein that catalyzes reactions in living organisms. Most reactions in the body require enzymes. Oxidation and reduction in terms of oxygen transfer the terms oxidation and reduction can be defined in terms of the adding or removing oxygen to a compound. Oxidation is the gain of oxygen. Reduction is the loss of oxygen. Oxidation and reduction in terms of oxygen transfer BUILDING BLOCKS Biological Molecules Quiz Time! THE CHEMISTRY OF LIFE (BIOMOLECULES) THE CHEMISTRY OF LIFE (BIOMOLECULES) THE CHEMISTRY OF LIFE (BIOMOLECULES) Exploring the Structure and Function of Biological Molecules ACTIVITY 1 Exploring the Structure and Function of Biological Molecules ACTIVITY 2