Carbohydrates

1. Carbohydrates Grade 10 Biology

2. Your Assignment

3. Your Carbohydrate Assignment 1. What defines a carbohydrate and what is its function in both plant and animal cells? 2. Monosaccharides (-oses): structure, and the ratio of C:H:O 3. Disaccharides: reaction used to join them, removal of water, sucrose, maltose and lactose. 4. Polysaccharides: starches (glycogen & cellulose) 5. What are the main uses of carbohydrates in cells (plants and animals)?

4. Additional Resources (1) The Tree of Life, lipids and Carbohydrates topic

5. Additional Resources (2) Carbohydrate Website links • http://www.s-cool.co.uk/a-level/biology/biological-molecules-and-enzymes/revise-it/carbohydrates • http://www.sciencemag.org/site/feature/data/carbohydrates.xhtml • Molecular Workbench Carbohydrates Module:

6. Polymerization • Organic compounds are formed by polymerization • Large carbon compounds are built up from smaller simpler molecules called MONOMERS • Monomers can bind to one another to form complex molecules known as POLYMERS • Macromolecules are very large polymers

7. Polymerization

8. Building and Breaking Polymers • Monomers link to form polymers through a chemical reaction called a CONDENSATION REACTION or Dehydration Synthesis • Water is released during the formation of polymers • The BREAKDOWN of some complex molecules, such as polymers, occurs through a process known as HYDROLYSIS • Hydrolysis is the reversal of a condensation reaction

9. Dehydration Synthesis

10. Hydrolysis

11. 4 Groups of Organic Compounds Found in Living Things • Carbohydrates (C-H-O 1:2:1 ratio) • Lipids (C-H-O) • Proteins (C-H-O-N)…sometimes S • Nucleic Acids (C-H-O-N-P)

13. Carbohydrates • MONOSACCHARIDES are simple sugars in a 1:2:1 ratio • GLUCOSE • GALACTOSE = sugar found in milk • FRUCTOSE = fruit sugar • Chemical composition (C6 H12 O6)

14. Simple carbohydrates: monosaccharides • Monosaccharides(simple/single sugars) have the empirical molecular formula of CH2O • Glucose: C6H12O6 is the most common monosaccharide • Can exist in linear or ring form • Carbohydrates can be simple sugars (fructose, galactose, glucose etc.) or polymers made from these simple sugars Glucose

15. Important Monosaccharides

16. ISOMERS

18. Carbohydrates

19. Simple carbohydrates: Disaccharides Disaccharides are made up of 2 monosaccharides that have undergone a dehydration reaction (e.g. sucrose, maltose, lactose); formula is C12H22O11 Disaccharides consist of 2 monosaccharides covalently bonded together by a glycosidic linkage which forms by dehydration synthesis (condensation reaction)

20. Carbohydrates DISACCHARIDES: two single sugars(monosaccharides) linked together by glycosidic linkage (Dehydration synthesis) • Lactose = glucose + galactose • Maltose: glucose dimer • Sucrose = Table sugar

21. Why is milk the energy source for baby mammals?

22. In most mammals, levels of β-galactosidase decreases with maturity as milk consumption declines • Genes for lifelong β-galactosidase production evolved in human communities which depended on milk and milk products for energy

23. Disaccharides

24. Polysaccharides • Consist of 3 or more monosaccharides joined together (may be 100’s or 1000’s) • The function of a polysaccharide is determined by its sugar monomers and the position of the glycosidic linkages • Polysaccharides provide energy storage and structural material • 2 energy storage polysaccharides are starch (plant) and glycogen (animal) • 2 structural polysaccharides arecellulose (plants) and chitin (animals - exoskeleton) 17

25. Carbohydrates • Starch - Plants convert excess sugars into starches for long-term storage (Alpha linkage) • Glycogen -Animals store glucose in the form of polysaccharide glycogen in the liver and muscles to be used as quick energy • Cellulose -a structural polysaccharide contained in the cell walls of plants (ß linkage) • Chitin – a polysaccharide found in the cell walls of fungi and the exoskeletons of insects and arthropods

26. Storage Polysaccharides: Starch Found in plants (organelle plastids), made of glucose monomers joined by a 1-4 glycosidic linkage. Bond angles make the molecule helical • Amylose: simplest unbranched form • Amylopectin: more complex, branched form

27. Storage Polysaccharides: Glycogen Found in animals, stored in liver and muscle cells. Extensively branched • In humans, glycogen banks do not last longer than a day

28. Structural Polysaccharides: Cellulose • major component of plant cell walls • Plants produce 1011 ton of cellulose per year • Cellulose is a polymer of glucose, however it uses the β form, which gives it a different 3-dimensional shape • Cellulose forms straight unbranched chains

29. Cellulose • Because of the different structure, very few organisms have the enzymes necessary to break down cellulose • Makes it a very strong and resistant“insoluble fiber”

31. Chitin • Carbohydrate used by arthropods (insects, spiders, crustaceans, and related animals) to build their exoskeletons • Also used for cell walls in fungi • Feels leathery and can become hardened when encrusted with calcium carbonate (shells) • Similar to cellulose molecules except the glucose has a nitrogen-containing side group