General Biology 11/2 Carbohydrates PDF

Lesson 5.1 Carbohydrates General Biology 11/2 Science, Technology, Engineering, and Mathematics To fuel our bodies in our activities, we consume meals as an essential part of our daily routine, and breakfast is considered the most important meal of the day. 2 One must a...

Lesson 5.1 Carbohydrates General Biology 11/2 Science, Technology, Engineering, and Mathematics To fuel our bodies in our activities, we consume meals as an essential part of our daily routine, and breakfast is considered the most important meal of the day. 2 One must also be aware that excessive consumption of carbohydrates can lead to diseases, such as diabetes and obesity. 3 How would you describe the structure and functions of carbohydrates? 4  Learning Competencies At the end of the lesson, you should be able to do the following: Categorize the biological molecules (carbohydrates) according to their structure and function (STEM_BIO11/12-Ii-j-15). Explain the role of each biological molecule in a specific metabolic process (STEM_BIO11/12-Ii-j-16). 5  Learning Objectives At the end of the lesson, you should be able to do the following: Identify the structure and function of carbohydrates. Describe the different types of carbohydrates. Explain the role of carbohydrates in specific metabolic processes. 6  Carbohydrates Used as a source of energy, carbohydrates are a class of biomolecules that includes sugar and polymers of sugars. Bread is a good source of carbohydrates. 7 Carbohydrates Carbohydrates such as cellulose act as structural molecules in the cell wall of plants. 8 Carbohydrates Carbohydrates such as chitin act as structural molecules in the exoskeleton of crutaceans. 9  Structure and Functions of Carbohydrates Carbohydrates These are organic compounds that The ratio of carbon, primarily consist of hydrogen and oxygen is 6:12:6 or 1:2:1 ratio carbon, hydrogen, and oxygen that occur in a 1:2:1 ratio The chemical composition of glucose showing carbon, oxygen, and hydrogen 10  Structure and Functions of Carbohydrates Photosynthesis is the primary source of sugars, particularly glucose, for cells of plants themselves and for the rest of the organisms of an ecosystem. Cells oxidize glucose to release energy that will drive other biochemical reactions. 11  Structure and Functions of Carbohydrates Monosaccharides: Oligosaccharides: two to ten simple sugars monosaccharides Classification of Carbohydrates Polysaccharides: hundreds to thousands of monosaccharides monomers 12  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides mono one sacchar sugar Monosaccharides are the monomers and fundamental units of carbohydrates that cannot be further broken down or hydrolyzed into smaller sugars. 13  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides What are the It can be aldoses types of or ketoses. monosaccharides? 14  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Aldoses are sugar What are the units that types of contain an aldehyde monosaccharides? group (shown in blue) 15  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Ketoses are sugar What are the units that types of contain a ketone group monosaccharides? (shown in blue) 16  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Monosaccharides Where do we occur in various usually encounter forms and are monosaccharides? abundant in nature. 17  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Glucose, which is also known as dextrose, is the form that circulates in our bloodstream.  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Fructose occurs in ripe and sweet fruits, such as mangoes, the sweetest fruit on the planet.  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Galactose makes up the sugar in milk.  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Deoxyribose, a pentose, is a major structural component of DNA nucleotides.  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides These are molecules with the same molecular What are isomers? formula but different structures. 22  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides The hexoses glucose, galactose, and fructose are considered isomers. 23  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides These are ring-shaped What is a pyranose conformations of ring? monosaccharides which is favorable in aqueous solutions. 24  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Monosaccharides with five to six carbon atoms usually occur as pyranose rings in aqueous or water-based solutions. 25  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides What are the two The 𝛼-glucose and conformations of 𝜷-glucose glucose? 26  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides If the OH group of the C1 is “below the ring” or on the opposite side of the CH2OH group, it is an 𝛼-glucose. 27  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides If the OH group of the C1 is “above the ring” or on the same side as the CH2OH group, it is a 𝜷-glucose. 28  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides oligo few sacchar sugar An oligosaccharide is a carbohydrate that consists of two to ten units of monosaccharides. The most commonly occurring forms of oligosaccharides are disaccharides (di=two). 29  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Disaccharides are How are formed by disaccharides dehydration formed? synthesis. 30  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Dehydration synthesis, also known as condensation reaction, occurs when the hydroxyl group (shown in red) of glucose combines with the hydrogen (shown in red) of fructose. 31  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides When two monosaccharides are combined into a disaccharide, a glycosidic bond (𝛼-1,2 glycosidic linkage) holds them together. 32  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides We encounter Where do we many forms of usually encounter disaccharides disaccharides? daily. 33  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Sucrose in plants is abundant in sugarcane, which is processed to produce table sugar. 34  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Maltose in barley can be fermented to produce alcoholic beverages. 35  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Lactose is the major sugar found in cow’s milk. 36  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides A B C D Raffinose, a trisaccharide, is found in cabbages and asparagus. 37  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Poly many sacchar sugar Polysaccharides are large molecules that consist of hundreds to thousands of monosaccharide monomers. They are long chains of complex carbohydrates. 38  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides The most common What are the most polysaccharides common are cellulose, polysaccharides? chitin, starch, and glycogen. 39  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Polysaccharides are composed of very long chains of monosaccharides. The orientation of bonds and the presence of branching determine their properties. 40  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Starch is the primary storage polysaccharide in plants. 41  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Glycogen is the storage polysaccharide in animal and fungal cells. 42  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Cellulose is the major component of plant cell walls, which makes it the primary structural carbohydrate in plants. 43  Structure and Functions of Carbohydrates Monosaccharides Oligosaccharides Polysaccharides Cellulose molecules occur in very long fibers of glucose chains. The glucose units are bound by 𝜷-1,4 glycosidic linkages. 44 Why is it good to have a high-fiber diet? What food products are rich in fiber? 45 How are carbohydrates involved in certain metabolic processes? 46  Metabolic Processes Involving Carbohydrates Carbohydrate metabolism involves several pathways. Those with the suffix –lysis are catabolic mechanisms, whereas those with the suffix –genesis are anabolic processes. 47  Check Your Understanding Identify the terms being described in each of the following statements. 1. These biomolecules consist of oxygen, hydrogen, and carbon that occur in 1:2:1 ratio. 2. This fundamental unit of carbohydrates may contain three to six carbon atoms. 3. These molecules have the same molecular formula but different structures. 48  Check Your Understanding Write true if the statement is correct and write false if it is otherwise. 1. Polysaccharides are simple carbohydrates that contain long chains of sugars. 2. Starch and glycogen both function as storage molecules. 3. Glycogen is an unbranched polymer of glucose molecules. 49  Let’s Sum It Up! Carbohydrates are organic compounds that consist of carbon, hydrogen, and oxygen in a 1:2:1 ratio. They have an empirical formula of (CH2O)n, where n is the number of carbon atoms. 50  Let’s Sum It Up! Carbohydrates are one of the four major groups of biomolecules. The three main classes of carbohydrates in living systems are monosaccharides, oligosaccharides, and polysaccharides. They are grouped according to the number of monomers present in their molecules. 51  Let’s Sum It Up! The simplest carbohydrates are the monosaccharides, which may have three to eight carbon atoms. Simple sugars or monosaccharides are the fundamental units of carbohydrates that cannot be broken down into simpler sugars. 52  Let’s Sum It Up! An oligosaccharide is a carbohydrate composed of two to ten monosaccharide units. The most common oligosaccharides are disaccharides, which consist of two monosaccharides. 53  Let’s Sum It Up! Carbohydrates with multiple monosaccharide units are formed by dehydration synthesis or condensation reaction. In this process, glycosidic bonds are formed between the monosaccharides. 54  Let’s Sum It Up! Polysaccharides are large molecules consisting of hundreds to thousands of monosaccharides. They are complex carbohydrates that contain long chains of sugars or polymers of monosaccharides. 55  Let’s Sum It Up! Carbohydrate metabolism is a group of biochemical processes that ensures the generation of energy from carbohydrates, as well as storing them in some tissues when present in excess quantities. 56  Let’s Sum It Up! Graphical representation of classes and functions of carbohydrates in living organisms 57 Challenge Yourself How do the three main types of carbohydrates differ from each other in terms of their sugar composition? 58 Bibliography Hoefnagels, Marielle. Biology: The Essentials. 2nd ed. McGraw-Hill Education, 2016. Mader, Sylvia S., and Michael Windelspecht. Biology. 11th ed. McGraw-Hill Education, 2014. Reece, Jane B, Martha R. Taylor, Eric J. Simon, Jean L. Dickey, and Kelly Hogan. Biology Concepts and Connections. 8th ed. Pearson Education South Asia Pte Ltd., 2016. Simon, Eric J., and Jane B. Reece. Campbell Essential Biology. 5th ed. Pearson Education Inc., 2013. 59 Bibliography Starr, Cecie, Christine A. Evers, and Lisa Starr. Biology Applications and Concepts. 8th ed. Cengage Learning Asia Pte. Ltd., 2012. Starr, Cecie, Christine A. Evers, and Lisa Starr. Biology Today and Tomorrow. 4th ed. Cengage Learning Asia Pte Ltd., 2014. Tabinas, Camilo A. “I AM RICE: A Teaching Activity on the Digestion of Carbohydrates.” Science 2.0 Join the Revolution. Science 2.0, January 1, 2010. https://www.science20.com/flexi_chem_teacher/blog/i_am_rice_a_teaching_activity_on_the_diges tion_of_carbohydrates-63075. Last accessed on April 13, 2020. 60