Exploring Water: The Chemistry of Life

1. Wednesday, 8/21- PreAP • Look over pre-tests (but don’t keep them!) • Finish discussing DHMO • Answer the following in your bell work section – • Why is water necessary for life?

2. Thursday, 8/22 – Bio 1 • Don’t forget our CTJ Meeting. I will be moving seats today if I need to. • Get out your water notes. I gave these to you on Tuesday, but we didn’t get to them • Water lab after notes • pH notes and lab if time

3. CTJ Meeting • Your Job • Come prepared everyday • Stay on task and work each day • Don’t distract your classmates • My Job • Teach the material • Assess the learning of every member in the class • Keep you safe

4. CTJ Meeting • What you will do… • Be respectful (You are already doing a GREAT job of this) • Do not talk unless you have been called on • Give me your best effort each day (it’s only 90 minutes!) • What I will do… • Quick seat adjustment now, more changes to come based on Unit 1 grade. • Citizenship point loss for disrupting class (no warning required anymore) • REWARD GOOD BEHAVIOR WITH FREE TIME. 

5. What to do about the world’s most deadly compound… Dihydrogen monoxide (DHMO)

6. Unit 2 – Bio-molecules and Biochemistry The Chemistry of Life

7. It all starts with Water • Life depends on water! • Why do you think water is so special? • Water’s formula is H2O, two hydrogens covalently bonded to one oxygen.

8. Water’s Shape • Water is a polar molecule • Oxygen is slightly negative • The Hydrogens are slightly positive • Since positive and negative charges attract, this creates a weak bond called a hydrogen bond.

9. COHESION • Due to the hydrogen bonds… • Water molecules stick to other water molecules. This is called Cohesion. (Co – think couple) • Surface Tension – enables organisms to walk on the water • Capillary action – works with adhesion to draw water up the roots and stems of plants

10. ADHESION • Due to the hydrogen bonds… • Water molecules stick to other surfaces. This is called Adhesion (think adhesive, like glue) • Works with cohesion to provide capillary action in plants

11. High Specific Heat • Water resists changing temperature • 3/4ths of Earth is covered in water which absorbs or releases heat • Creates very stable marine and coastal environments • Prevents extreme temperature fluctuations like those on other planets

12. Evaporative Cooling • As water evaporates, it removes heat from a surface • This is how sweating keeps you cool!

13. Density of Water • Water doesn’t follow the normal rule of density. MOST solids sink because they are very dense, but solid water (ice) floats because it is less dense. • Becomes more and more dense until 4*C • Expands after 4*C and Freezes at the lowest density at 0*C • Floating ice prevents lakes and streams from freezing solid.

14. Density of Water (Gas)

15. Density of Water (Liquid)

16. Density of Water (ICE)

17. Water – the Universal Solvent • Water will dissolve just about anything which makes it important for chemistry in living things • Hydrophilic – water loving, substances that dissolve easily in water (i.e. salt) • Hydrophobic – water fearing, substances that will not dissolve in water, these are non-polar compounds (i.e. oil)

18. Thursday, 8/22 - PreAP • In your bell work section, answer the following question. (If you write in complete sentences, then you do not have to write the question) • Which is more dangerous – Acid, Base, or Fire? Why?

19. pH Scale – Acids and Bases • The pH scale is used to determine if a solution is an acid or a base. • Acids are found below 7. They get stronger as you approach zero. • Neutral substances (like pure water) can be found exactly at 7. • Bases are found above 7. They get stronger as you approach 14.

20. pH levels and Biology • Strong acids and strong bases cause damage to cells • Living things must maintain a consistent pH level (typically from 6-8) by using buffers, which are substances that can bring a pH level back to normal. • Where do you think most of the buffers in your body are found and why? • Acid Rain is a major pollutant concern in biology • Rain or snow with a pH lower than 5.6 can damage forests and lakes or streams. • Caused by smoke mixing with rain water and lowering the pH level.

21. Effects of Acid Rain

22. The pH Scale 1 1 2 2 3 3 4 4 5 5 6 6 7 8 9 9 10 10 11 11 12 12 13 14 Strong Acid Weak Acid Neutral Weak Base Strong Base

23. Friday, 8/22 - PreAP • Finish Penny Lab • Macromolecule Notes • Macromolecule Webquest on your own

24. Macromolecules • Every living thing is made of a combination of Carbon, Hydrogen, Oxygen, Nitrogen, Phosporus, and Sulfur with a few other minor elements in small quantities. • All living things are made of and depend on carboyhdrates, lipids, nucleic acids, and proteins

25. Carbohydrates • Monomer – carbon rings or sugars; one or two rings – simple sugar; chains of rings – starch • Look for – carbon rings OR a formula of only CHO with twice as many H as O. (ex- C6H12O6) • Uses – primary energy source (aka food) • Test – Benedict’s reagent turns orange with simple sugar; Iodine turns black with starch • Draw Them

26. Examples of Carbohydrates

27. Lipids (fats) • Monomer – fatty acids (chains of carbon-hydrogen bonds); saturated fats are straight lines, unsaturated fats are bent • Look for – Capital “E” shape OR a C-H chain OR a CHO formula with very few O (ex. C9H18O2) • Uses – long term energy storage, warmth, cell membrane, water proofing • Test – Creates an oil spot on brown paper OR Sudan Red stains lipids dark red • Draw Them

28. Lipid Examples

29. Nucleic Acids (DNA or RNA) • Monomer – Nucleotides (phosphate molecule, sugar molecule, and oxygen base) • Look for – the P for phoshorus OR a spiral helix shape • Uses – stores genetic information and the info to make proteins • Test – No test, they are in everything that is living • Draw Them

30. Nucleic Acid Examples

31. Proteins • Monomer – amino acids • Look for – Nitrogen with no phosphorus OR the “amino head” • Uses – Keep you alive! (Proteins do almost everything from digesting food to coloring your eyes.) • Test – Biuret’s reagent turns dark purple in the presence of protein • Draw Them

32. Protein Example