1. 3.2 Carbohydrates, lipids and proteins IB Biology

2. Organic Molecules What is organic? What is organic?  Carbon-containing compounds in living things  Usually carbon covalently bonded to carbon  Also methane (CH 4 ) What is inorganic? What is inorganic?  ALL molecules without carbon  ALSO carbon oxides, and carbonates  Examples: CO 2, CO, H2CO 3, CaCO 3

3. Structural formulas Show how all of the atoms in a compound are bound together Condensed structural formula has removed the bonds between other atoms like hydrogen Condensed structural formula Structural formula

4. Macromolecules Large molecules made up of repeating subunits of smaller molecules called monomers MacromoleculeMonomer Carbohydratemonosaccharides Lipidsfatty acids Proteinsamino acids Nucleic acidsnucleotides

5. Carbohydrates All contain carbon, oxygen, and hydrogen All contain carbon, oxygen, and hydrogen Often have a ring structure Often have a ring structure Usually have the formula: Usually have the formula:  C n H (2n) O n Ratio of 2H:1O

6. Monosaccharides Monomer (building block) of carbohydrates Single sugars Sweet taste Examples include:  Fructose – gives sweet taste to many fruits, attracting consumers that will spread the seeds  Glucose – part of metabolism, transported through the blood in animals to provide energy to cells  Galactose – in peas, and PART of lactose

7. Examples of monosaccharides Glucose Fructose GlucoseRiboseDeoxyribose

8. Disaccharides Two monosaccharides covalently bonded: Two monosaccharides covalently bonded: + = + = Examples include: Examples include:  Sucrose (table sugar)  Transported for energy in plant phloem  Lactose (in milk)  Provides energy for young animals  Maltose (“malt” flavoring)

9. Condensation Join monomers together (creates a covalent bond) Join monomers together (creates a covalent bond) Creates a water molecule (loss of hydroxyl (OH) from one monomer and hydrogen (H) from the other) Creates a water molecule (loss of hydroxyl (OH) from one monomer and hydrogen (H) from the other)

10. Condensation Join monomers together (creates a covalent bond) into a macromolecule Join monomers together (creates a covalent bond) into a macromolecule Monomer + monomer macromolecule + water Monomer + monomer macromolecule + water

11. Hydrolysis Splitting macromolecule back into monomers Splitting macromolecule back into monomers Water is added to the reaction Water is added to the reaction

12. Hydrolysis Splitting macromolecule back into monomers Splitting macromolecule back into monomers Water is added to the reaction Water is added to the reaction

13. Hydrolysis Splitting macromolecule back into monomers Splitting macromolecule back into monomers Water is added to the reaction Water is added to the reaction macromolecule + water monomer + monomer macromolecule + water monomer + monomer

14. Polysaccharides Many sugars covalently bonded together Many sugars covalently bonded together Examples include: Examples include:  Chitin: used for strength and support in insect skeletons and fungal cell walls  Cellulose: forms fibers used for strength and support in plant cell walls  Glycogen: used for short-term energy storage in animals, found in muscles and liver  Starch: used for energy storage in plants

15. Polysaccharide examples Chitin= Chitin= Cellulose= Cellulose= Glycogen= Glycogen= Starch= Starch=

16. Lipids

17. Lipids Lipids - include steroids, waxes, fatty acids and triglycerides Lipids - include steroids, waxes, fatty acids and triglycerides Triglyceride = 3 fatty acids + 1 glycerol Triglyceride = 3 fatty acids + 1 glycerol = fat if solid at room temp. = fat if solid at room temp. = oil if liquid at room temp. = oil if liquid at room temp. Used in membrane structure, cell-to-cell communication, buoyancy, and more. Used in energy storage, thermal insulation, membrane structure, cell-to-cell communication, buoyancy, and more.

18. Lipids Two building blocks: / OH Two building blocks: / OH Glycerol:C 3 H 8 O 3 Fatty acid:CH 3 -(CH 2 ) x -C=O

19. Condensation of glycerol and fatty acids Forms a triglyceride

20. Energy Storage Lipids Lipids ~9 Calories / gram (twice as much energy per gram) ~9 Calories / gram (twice as much energy per gram) Long-term storage Long-term storage Non-polar (water insoluble) Non-polar (water insoluble) Carbohydrates ~4 Calories / gram ~4 Calories / gram Short-term storage Short-term storage Polar, water soluble Polar, water soluble

21. The Love / Hate Relationship with Carbs and Lipids

22. Inhibits absorption of some vitamins and nutrients Replaces 3 OH groups on sucrose with 3 Cl to make it stable Sweetener in Splenda Made with sucrose instead of glycerol

23. Proteins Made up of amino acid monomers Over 20 amino acids with variable “R” group “R” group can be polar, non-polar, positively or negatively charged

27. Model an Amino Acid

28. Condensation of Amino Acids Join together (creates a covalent bond) Join amino acids together (creates a covalent bond) in a peptide bond

29. Functions of Protein Two categories of proteins:  Fibrous - elongated shape, tough, insoluble in water  Globular - compact/rounded shape, water- soluble Functions: enzymes, hormones, transport, strength in tissue, defense against disease

31. Homework Pg. 52 #1-3 Research: What is Splenda®? How does it’s molecular shape help it replace sugar?

32. Protein Structure - HL Structure determines biological activity of molecule Primary structure - polypeptide chain made up of amino acid sequence Secondary structure - due to the folding of polypeptide chains into  - helix or  -pleated sheets

33. Protein Structure Tertiary Structure - overall 3-D shape of protein due to interactions between R-groups of aa and with surrounding water medium Quaternary structure - the way polypeptides fit together when there is more than one chain