The Major Biomolecules - GenBio Discussion PDF

The Major ◤ Biomolecules  ◤ One of the common features of organisms here on Earth is their biochemical composition. All organisms contain a common set of chemicals, such as carbon , oxygen , nitrogen phosphorus , sulphur, and hydrogen. , which build larger and more complex molecules necessar...

The Major ◤ Biomolecules  ◤ One of the common features of organisms here on Earth is their biochemical composition. All organisms contain a common set of chemicals, such as carbon , oxygen , nitrogen phosphorus , sulphur, and hydrogen. , which build larger and more complex molecules necessary in life. ▪ These ◤ large molecules-carbohydrates , lipids , proteins, and nucleic acids –combine to produce different structures or substances that perform specific functions in the cell. These are called BIOMOLECULES. Also known as organic molecules or macromolecules due to their large size and complex nature. ▪ Biomolecules serve as fuel for the metabolism of organisms. ▪ Their chemical composition and quantity are important for cellular activities proceed. ▪ Carbohydrates ◤ are biomolecules believed to be the most abundant of all organic compounds. This is based the assumption that cellulose , a type of carbohydrate , is produced by numerous photosynthetic organisms daily through photosynthesis. IT is said that more than 75% of the dry weight of plants is carbohydrate in nature. ▪ Majority of carbohydrates have a carbon- hydrogen0oxygen ratio of 1:2:1. The term carbohydrate literally means ‘hydrated carbon’.  ◤ ▪ Carbohydrates include simple and complex sugars. Carbohydrates are well-known as a great source of energy. ▪ When our bodies are powered by energy, our brains function well and our muscles can work properly.  ◤ Types and Functions of Carbohydrates 1. Monosaccharides 2. Disaccharides 3. Polysaccharides ▪ Monosaccharides ◤ are also called simple sugars because they are monomers, or the single structural units , of some complex carbohydrates. ▪ They can be classified as aldoses or ketoses according to the placement of chemicals in the structures. ▪ Aldoses are characterized by the presence of an aldehyde (-CHO), usually at the terminal or first carbon atom. ▪ Ketoses ◤ – are characterized by having a carbonyl (C=O) group , or a ketone , which usually located at the second carbon atom of the molecule. ▪ When carbonyl group is mixed with the hydroxyl group (-OH) in an aqueous solution, the result is a cyclic compound (either hemiacetal or hemi –ketal), which looks like a water-soluble crystalline solid. ▪ RNA ◤ is one of those responsible for encoding the genetic information found in DNA. ▪ Glucose , a hexose (an organic compound composed of six carbon atoms), is another important example of a monosaccharide, as it is a major source of energy for all organisms. ▪ Fructose which found in the most plants such as sugarcane, sugar beets , and corn.  ◤ ▪ Different forms of fructose are used in different items and drinks to enhance their taste. ▪ Some derivatives of monosaccharides are also important. Ascorbic acid (Vitamin C) comes from glucose. Sugar alcohols , such as sorbitol and mannitol , are sweetening agents. ▪ Disaccharides the second type of carbohydrates. ◤ ▪ They are composed two monosaccharides joined together through a process called condensation. ▪ In this process , dehydration synthesis takes place , wherein water is extracted upon combining the two molecules. ▪ The result of the condensation reaction is the formation of the glyosidic bond , a type of a covalent bond that links a carbohydrate molecule to another molecule (which maybe from another chemical group) Disaccharides ◤ are sweet and soluble in water. 1. Sucrose (table sugar) comes from combining glucose and fructose. Many food industries use sucrose as sweeteners to make candies, ice cream , cakes, cookies, breads, sauces, and preserved goods. Lactose ◤ (milk sugar) , a great source of nutrients for infants , is combination of glucose and galactose. Lactose is also used in many processed dairy products. People who do not produce enough lactase to digest lactose are called lactose intolerant. ▪ Maltose ◤ (malt or beer sugar) comes from two glucose molecules. It is the least sweet among the previously mentioned disaccharides; thus , it is not a common sweetener. Maltose is more common in making beer. ▪ The starches turn into maltose during the malting process.  ◤ Polysaccharides ▪ The third type of carbohydrates. ▪ Which are composed of at least three monosaccharides. ▪ Polysaccharides are not sweet. They do not form crystals when water molecules are removed. The actual ◤ structure of certain tissues or cellular parts may depend on the polysaccharides molecular structure , which is either branched or linear. A Linear polysaccharide forms a rigid structure and is insoluble in water. A branched polysaccharides is soluble in water. Most ◤polysaccharides are used for energy storage. Starch and glycogen are composed of chains of glucose molecules. In plants , energy storage is in the form of starch. In animals energy storage is in form of glycogen. ◤ ◤ ◤ ◤