Carbohydrates 2023 PDF

Your vibe attracts your tribe! Macromolecules Chapter 1.2 Pg. 18 - 20 What are macromolecules? Macromolecules are very large molecules important to living organisms. Most macromolecules are made of smaller subunits called “monomers.” There are 4 classes of macromolec...

Your vibe attracts your tribe! Macromolecules Chapter 1.2 Pg. 18 - 20 What are macromolecules? Macromolecules are very large molecules important to living organisms. Most macromolecules are made of smaller subunits called “monomers.” There are 4 classes of macromolecules: Crash Course Macromolecules: https://www.youtube.com/watch?v=pJqfmuuxNXs Activity: Sorting Foods Carbohydrates: General Info Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables, pop, candy, juice, and milk products. made of C, H & O and the functional groups carbonyl & hydroxyl General formula: (CH2O)n n = number of carbon atoms for glucose, n = 6, so formula is C6H12O6 names often end with -saccharide or -ose (i.e. monosaccharide or glucose) Functions of Carbohydrates 1. primary energy source - extra carbohydrate in body are stored as GLYCOGEN in liver or as FAT for later use 2. cell surface markers (i.e. for cell identification and communication) 3. help digest protein and fat. 4. used as building materials (i.e. chitin in insects, cellulose in plants) 5. serve as dietary fibre for humans Take out Drawing Macromolecules worksheet  6 Monosaccharides 5 4 1 Made of “1 sugar unit” 3 2 General formula is C6H12O6 6 5 ❑ structural isomers 4 1 These monosaccharides are mainly produced by digestion of complex carbohydrates 3 2 1 2 5 6 3 4 Why can these monosaccharides dissolve in water? Monosaccharides con’t When dissolved in water, and in cells, monosaccharides form a ring. The hydroxyl group on carbon 5 bonds to the aldehyde carbon 1 When dissolved in water, 50% chance that it will form alpha & 50% chance it will form beta  α 1, 2 – glycosidic linkage Disaccharides Formed from 2 monosaccharides glycosidic linkage 3 major disaccharides ❑ sucrose = glucose + fructose ❑ lactose = glucose + galactose ❑ maltose = glucose + glucose glycosidic linkage Building Disaccharides Condensation reaction of two glucose molecules results in the formation of maltose The C-O-C bond formed is called a glycosidic bond Show dehydration synthesis: glycosidic linkage glucose glucose Show dehydration synthesis of lactose: 𝛃 1, α 4 – glycosidic linkage galactose glucose Show dehydration synthesis of sucrose: 𝛃 1, α 2 – glycosidic linkage α glucose β fructose  What type of bonds do each have? Polysaccharides Which is the easiest to breakdown? Why? Polysaccharides are made by long chains of repeating units of monosaccharides connected by glycosidic linkages Exoskeleton is made of chitin. Polysaccharides (helical/ coiled ) (highly branched) (linear) Why can’t you digest grass (cellulose) ? Polysaccharides ❑ Cellulose gives structure to plants, fiber to our diet ❑ Starch produced by plants to store sugar ❑ Glycogen produced by animals to store glucose; stored in liver and muscle cells; after a meal, liver converts extra sugar into glycogen – to be used later when body is low on sugar ❑ Chitin forms the exterior of some crustaceans (ie. crabs, lobsters); provides structural support Dietary Fibre: What’s it good for? ❑ Dietary fiber (aka. roughage or bulk) is found in plant cells (i.e cellulose, lignin, pectin, hemicellulose) ❑ Fibre is non-digestible - your body can’t digest or absorb it ❑ Fibre (a) stimulates peristalsis movement and secretion of digestive enzymes (b) makes the stool bulky so it is easier to pass, (c) promotes growth of “good” gut bacteria ❑ Found in bran, whole-grain foods, raw vegetables and fruit (especially the seeds and skins), legumes, nuts, seeds and popcorn Polysaccharides con’t Chitin - forms exoskeletons; cell walls of fungi; - surgical thread is made from chitin  Starch Cellulose Each successive Glucose repeat glucose unit is units are facing upside-down in the same Both polymers relation to each of direction the glucose molecules that it Same monomer is connected to (glucose) Can be digested is not digested by Complex carbs humans (no enzymes) Soluble Insoluble (fiber / roughage) Weaker Stronger (good for building) Carbohydrate Structural Diagrams Carbohydrate Diagrams: Monosaccharides 1 2 3 4 5 6 Figure 1: Glucose (C6H12O6) has two isomers: 𝞪 and 𝛽. In 𝞪 glucose, the OH on carbon 1 is below the ring whereas the OH on carbon 1 of beta glucose is above the ring. In the linear form of glucose, the carbonyl group is attached to the first carbon. When the numbering carbons in the ring, the right most carbon is numbered 1 (after the carbonyl group). Carbohydrate Diagrams: Monosaccharides 1 2 3 4 5 6 Figure 2: Galactose (C6H12O6) is an isomer of glucose. In galactose, the carbonyl group is attached to carbon 1. Like glucose, galactose forms a 6 member ring. When numbering galactose in a ring, start at the right most carbon after the carbonyl group. Carbohydrate Diagrams: Monosaccharides 1 2 3 4 5 6 Figure 3: Fructose (C6H12O6) is an isomer of glucose. In fructose, the carbonyl group is attached to carbon 2. Unlike glucose, fructose forms a 5 member ring. When numbering fructose in a ring, start at the left most carbon. Carbohydrate Diagrams: Disaccharides maltose 𝞪 1, 4-glycosidic bond Figure 4: Maltose (C12H24O12) is a disaccharide formed from two glucose molecules. Maltose, also known as malt sugar, is used in brewing beer and making bread. It is naturally found in plants such as barley, rye, corn, sweet potatoes, pears, and peaches. It is also found in honey, molasses, bagels, and bread. Carbohydrate Diagrams: Disaccharides sucrose 𝞪 1, 2-glycosidic bond Figure 5: Sucrose(C12H24O12) is a disaccharide made from glucose and fructose. It is commonly known as table sugar. It is obtained from sugar cane and sugar beets. Carbohydrate Diagrams: Disaccharides lactose 𝛽 1, 4-glycosidic bond Figure 6: Lactose(C12H24O12) is a disaccharide made from glucose and galactose. It is one of the sugars found in milk.  Polysaccharides: Starch Starch α 1-4 or α 1-6 glycosidic bonds Figure 7: Starch is the most important source of carbohydrates in the human diet and accounts for more than 50% of our carbohydrate intake. It can be found in seeds (especially the cereal grains) and tubers. A starch molecules contains hundreds of glucose molecules in either branched chains (amylopectin) or unbranched chains (amylose) Natural starches consist of about 10%–30% amylase and 70%–90% amylopectin. Amylose is made of D-glucose units joined by the α-1,4-glycosidic linkages. Amylopectin is a branched-chain made of glucose units linked primarily by α-1,4-glycosidic bonds but with occasional α-1,6-glycosidic bonds, which are responsible for the branching.  Polysaccharides: Glycogen Glycogen α 1-4 or α 1-6 glycosidic bonds Figure 8: Extra glucose in converted into glycogen and stored in the liver and muscle cells. When fasting, animals draw on these glycogen reserves during the first day without food to obtain the glucose needed to maintain metabolic balance. Glycogen is highly branched, like amylopectin. It is made of hundreds of glucose subunits linked by alpha 1-4 glycosidic bonds, with occasional alpha 1-6 glycosidic bonds which provide branching points.  Polysaccharides: Cellulose Cellulose β 1-4 glycosidic bonds Figure 9: Cellulose is found in all plants. It is made of hundreds of glucose units joined by by β-1,4-glycosidic linkages. The adjacent chains also form hydrogen bonds between OH groups of glucose molecules. As a result, cellulose exhibits little interaction with water or any other solvent. Cotton and wood, for example, are completely insoluble in water and have considerable mechanical strength. Humans are unable to metabolize cellulose as a source of glucose because we lack enzymes that can hydrolyze the β-glycosidic linkages found in cellulose