1. UNIT 4 MACROMOLECULES Biology Lesson 1: The Chemical Basis of Life

2. Topics to be covered: 1.Properties of Water 2.Organic Molecules 3.Enzymes

3. Water three A water molecule (H 2 O), is made up of three atoms --- one oxygen and two hydrogen. H H O

4. Water is Polar oxygen atom attracts more electrons In each water molecule, the oxygen atom attracts more than its "fair share" of electrons oxygennegative The oxygen end “acts” negative hydrogenpositive The hydrogen end “acts” positive POLAR Causes the water to be POLAR neutral Zero Net Charge However, Water is neutral (equal number of e- and p+) --- Zero Net Charge

5. Hydrogen Bonds Exist Between Water Molecules Formed between a highly Electronegative atom of a polar molecule and a Hydrogen Formed between a highly Electronegative atom of a polar molecule and a Hydrogen One hydrogen bond is weak, but many hydrogen bonds are strong One hydrogen bond is weak, but many hydrogen bonds are strong

6. Interaction Between Water Molecules Negative Oxygen end of one water molecule is attracted to the Positive Hydrogen end of another water molecule to form a HYDROGEN BOND

7. Properties of Water At sea level, pure water boils at 100 °C and freezes at 0 °C. At sea level, pure water boils at 100 °C and freezes at 0 °C. The boiling temperature of water decreases at higher elevations (lower atmospheric pressure). The boiling temperature of water decreases at higher elevations (lower atmospheric pressure). For this reason, an egg will take longer to boil at higher altitudes For this reason, an egg will take longer to boil at higher altitudes

8. Properties of Water Cohesion Cohesion Adhesion Adhesion High Specific Heat High Specific Heat High Heat of Vaporization High Heat of Vaporization Less Dense as a Solid Less Dense as a Solid

9. Cohesion Attraction between particles of the same substance (why water is attracted to itself) Attraction between particles of the same substance ( why water is attracted to itself) Results in Surface tension (a measure of the strength of water’s surface) Results in Surface tension (a measure of the strength of water’s surface) Produces a surface film on water that allows insects to walk on the surface of water Produces a surface film on water that allows insects to walk on the surface of water https://www.youtube.com/watch?v=45 yabrnryXk https://www.youtube.com/watch?v=45 yabrnryXk https://www.youtube.com/watch?v=45 yabrnryXk https://www.youtube.com/watch?v=45 yabrnryXk

10. Cohesion … Helps insects walk across water

11. Adhesion Attraction between two different substances. Attraction between two different substances. Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton. Water will make hydrogen bonds with other surfaces such as glass, soil, plant tissues, and cotton. Capillary action-water molecules will “tow” each other along when in a thin glass tube. Capillary action-water molecules will “tow” each other along when in a thin glass tube. Example: transpiration process which plants and trees remove water from the soil, and paper towels soak up water. Example: transpiration process which plants and trees remove water from the soil, and paper towels soak up water.

12. Adhesion Causes Capillary Action Which gives water the ability to “climb” structures

13. Adhesion Also Causes Water to … Form spheres & hold onto plant leaves Attach to a silken spider web

14. High Specific Heat Amount of heat needed to raise or lower 1g of a substance 1° C. Amount of heat needed to raise or lower 1g of a substance 1° C. Water resists temperature change, both for heating and cooling. Water resists temperature change, both for heating and cooling. Water requires more heat energy for its temperature to change. Water requires more heat energy for its temperature to change.

15. Water and Heat Energy Water releases heat very slowly. Heat of vaporization – amount of heat needed for water to evaporate (condensing/evaporating). Heat of fusion – amount of heat water loses to turn from a liquid to a solid. (freezing/melting)

16. Water vapor Water vapor forms a kind of global ‘‘blanket” which helps to keep the Earth warm. Heat radiated from the sun Heat radiated from the sun warmed surface of the earth is absorbed and held by the vapor by the vapor.

17. Water is Less Dense as a Solid Ice is less dense Ice is less dense as a solid than as a liquid (ice floats) hydrogen bonds constantly being broken and reformed. Liquid water has hydrogen bonds that are constantly being broken and reformed. Frozen water crystal-like lattice Frozen water forms a crystal-like lattice whereby molecules are set at fixed distances.

18. Water is Less Dense as a Solid Which is ice and which is water?Which is ice and which is water?

19. Water is Less Dense as a Solid WaterIce

20. Water animation http://lab.concord.org/embeddable.html#inte ractives/sam/intermolecular-attractions/6- hydrogen-bonds-a-special-type-of- attraction.json http://lab.concord.org/embeddable.html#inte ractives/sam/intermolecular-attractions/6- hydrogen-bonds-a-special-type-of- attraction.json

21. Homeostasis Ability to maintain a steady state despite changing conditions Ability to maintain a steady state despite changing conditions Water is important to this process because: Water is important to this process because: a. Makes a good insulator b. Resists temperature change c. Universal solvent d. Coolant e. Ice protects against temperature extremes (insulates frozen lakes)

22. Universal Solvent “nearly” universal solvent “nearly” universal solvent Because of its polar properties water can dissolve other polar substances. Because of its polar properties water can dissolve other polar substances. “like dissolves like” “like dissolves like” Ex. Sugar water, salt water Ex. Sugar water, salt water

23. Lesson 2: Organic Molecules: Lipids and Carbohydrates Organic compounds – contains carbon and hydrogen. (You will often find these elements as well: oxygen, nitrogen, phosphorus)

24. What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Monomers are complex large molecules. FALSE

25. What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE DNA is a macromolecule. TRUE

26. What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Sugar is a carbohydrate. TRUE

27. What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Protein stores energy. FALSE

28. What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Lipids store more energy than carbohydrates. TRUE

29. Student learning objectives Students will explain how carbon is uniquely suited to form biological macromolecules (ref. BIO.A.2.2.1). Students will compare the structure and function of carbohydrates, lipids, proteins, and nucleic acids in organisms (ref. BIO.A.2.2.3). Students will describe how biological macromolecules form from monomers (ref. BIO.A.2.2.2).

30. MACROMOLECULES Very large molecules (polymers), made up of smaller organic molecules called monomers. (*MONOPOLY – one person owning all properties!) Made up of: nitrogen (only in proteins), oxygen, hydrogen, and carbon. BREAK IT DOWN! Macro - large Mono – one Poly - many BREAK IT DOWN! Macro - large Mono – one Poly - many

31. What are the 4 macromolecules? 1.Carbohydrates 2.Proteins 3.Lipids 4.Nucleic Acids

32. carbon So unique! Can bond to itself and other elements to make many different types of compounds.

33. How are polymers formed? Dehydration synthesis reaction: monomer + monomer  polymer + water

34. Review (from the bio keystone practice test)

37. Summary of the Organic Molecules: