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Chemistry of Life

Chemistry of Life. CHAPTER 2 Sections 1-4. Bellringer Q. A butterfly is made of atoms. This flower is made of atoms. Atoms make up the breakfast you ate and the skin on your feet. Atoms make up the pages of the book and the desk you are sitting on. Soo… Why are all these things different?.

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Chemistry of Life

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  1. Chemistry of Life CHAPTER 2 Sections 1-4

  2. Bellringer Q A butterfly is made of atoms. This flower is made of atoms. Atoms make up the breakfast you ate and the skin on your feet. Atoms make up the pages of the book and the desk you are sitting on. • Soo… Why are all these things different?

  3. Key Terms- Chapter 2, Section 1 • Atom- smallest unit of matter that can’t be broken by chemicals. Made of nucleus and electron cloud. • Nucleus- center of an atom • Protons- positive charge • Neutron- no charge • Electron cloud- space surrounding nucleus • Electron- negatively charged particle

  4. The Atom Protons and Neutrons are here

  5. Energy Levels in an Atom • Electrons are found in Energy Levels • 1st energy level holds max of 2 electrons • 2nd energy levels holds max of 8 electrons Foldable Periodic Table Activity

  6. Elements Q. Why do they call He, Cm, and Ba the 'medical elements'? A. Because, if you can't helium or curium, you barium!

  7. Which 4 elements are most common in the human body? • What do you know about these 4 elements?

  8. Very Important Elements • Four elements, Hydrogen, Oxygen, Carbon, Nitrogen make up 96% of living matter Nitrogen normal Nitrogen deprived

  9. About Periodic Table-Key info! • Atomic # : number of protons • Atomic mass: number of protons + neutrons • Electrons are what are “traded” • # of electrons in outside shell is determined by the column number (get rid of leading “1’s”) • Total # of electrons = Total # of protons = Atomic #

  10. Electrons • When an atom absorbs energy, electrons get excited and “jump up” to a higher energy level. • When an atom loses energy, electrons “fall back” to a lower energy level. Energy is given off as a form of light. • Exciting and then giving off energy as electrons “falling back” to a lower energy level is what makes neon signs glow.

  11. Explore the Periodic Table • What do you notice about the atomic numbers of the elements as you move across a row? • What do you notice about the mass numbers of the elements as you move across a row? • What is the atomic mass and number of an atom that has 6 protons, 8 neutrons, and 6 electrons? What element is that?

  12. Isotopes • Isotopes- atoms of same element, different numbers of neutrons. • Ex. Carbon-12 vs Carbon-14 (radioactive, decaying form used in fossil dating) • Ex. Nitrogen-14 vs. Nitrogen-15 (found more in marine sources) • Ex. Cobalt-60 (used in treating cancer patients and PET scans)

  13. Carbon-14. How many protons? How many electrons? How many neutrons? Carbon-12 How many protons? How many electrons? How many neutrons? Atomic number & Mass practice 6 6 6 6 6 8

  14. Compounds • Compound: substance that is composed of two or more different elements that are chemically combined • Ex. NaCl, MgSO4, etc • Compounds form by bonding, making the compound more stable than individual atoms.

  15. Biology is based on Chemistry • Nitric Oxide (NO) is a compound • It is an important chemical for: • Ewe – Lamb (mom to baby) recognition • Mouse memory retention • Lowering of blood pressure in humans • Cell to cell Communication

  16. Octet Rule • Object of the game is to get a full energy level • Remember: 1st shell full with 2 e- • Remember: 2nd shell full with 8 e- • This makes the atom stable • Unstable atoms react violently and bond in order to get stable http://theodoregray.com/PeriodicTable/Stories/011.2/Videos/SodiumParty06.html From a 145 gram total of sodium

  17. Moral of bonding… It is good =) • Sodium reacts violently with water • Chlorine is poisonous gas used as weapon in WWII • Table salt is used in our bodies, as a preservative, and in our food. So safe we use it everyday!

  18. Bonding, pg 29 • Covalent Bond-shares electrons. Strongest bond. • Ex. H2O (water), CO2 (carbon dioxide), O2 (oxygen)

  19. Bonding, pg 30 • Ionic Bond- steals electrons. Ex. NaCl • Ion- charged particle. Can be + or – • Opposites attract! Balloon Demo Why it works…. The + charges of your hair are attracted to the – charges in the balloon…. Cool!

  20. Bonding Comic

  21. Bonding, pg 29 • Hydrogen Bonds-attraction between hydrogen atoms • Ex. H2O • Hydrogen bonds are NOT true bonds

  22. Mixtures • Mixture: a combination of substances in which you can spot individual parts • Ex. Italian salad dressing, trail mix, etc.

  23. Solution • Solute- solid particles that dissolve • Solvent- what causes dissolving • Solution- homogenous mixture made from solute and solvent • Concentrated: when there is more solute than solvent • Diluted: when there is more solvent than solute Solute + Solvent = Solution

  24. Soluble- “able to be dissolved” A physicist, biologist and a chemist were going to the ocean for the first time. The physicist saw the ocean and was fascinated by the waves. He said he wanted to do some research on the fluid dynamics of the waves and walked into the ocean. Obviously he drowned and never returned. The biologist said she wanted to do research on the flora and fauna inside the ocean and walked inside the ocean. She too, never returned. The chemist waited for a long time and afterwards, wrote the observation, "The physicist and the biologist are soluble in ocean water".

  25. Water and Solutions- pg 31 How does water get to the tops of tall trees? • Cohesion- attraction between the same substance • Adhesion- attraction between different substances Colored water drop demo

  26. Polarity • Polar molecules- have unequal sharing of electrons in an atom • Polar molecules dissolve easily in water • Ex. salt, sugar, coco powder • Nonpolar molecules do not dissolve well in water • Ex. oil, butter, lard, etc

  27. pH Scale • Based on logarithmic scale • pH of 3 is 10x stronger than pH of 4 • pH of 3 is 100x stronger than pH of 5

  28. Acid Tastes sour pH < 7 Turn litmus paper red More H+ (hydrogen) Ex. Lemon juice, tomatoes, vinegar Bases Tastes bitter pH > 7 Turn litmus paper blue More OH- (hydroxide) Ex. Antacid, soap, ammonia Acids and Bases-Differences- pg33

  29. Acids & Bases Similarities • Acid & Bases conduct electricity • Acids & Bases react with each other to produce salt and water (this neutralizes the solution)

  30. More about pH • pH of 7 is “neutral” • Most water (also rain/snow) has pH of 6.5 • “Acid rain” has pH less than 5 Acid rain demo (chalk/limestone & vinegar)

  31. Acid Rain • Low pH kills fish eggs & some insects • Soil enzymes are destroyed- decomposition slows • Most plants can’t grow in very acidic soil • Ancient buildings, statues, gravestones erode

  32. Chemistry of Cells- Chapter 2, Section 3 4 Major Macromolecules • Carbohydrates • Lipids • Proteins • Nucleic Acids

  33. Macromolecules= large molecule • Macromolecules are made by stringing together of a bunch of “Monomers” together. • These little molecules are joined together by dehydration synthesis (water is removed) to make Macromolecules • Polymers are large molecules consisting of many repeating subunits of monomers (remember: Gak!) • To break these macromolecules apart (disassemble) water is added and the molecule separates.

  34. Carbohydrates= “sugar or starch” • Monosaccharides- “one sugar molecule” • Glucose- made by green plants • Galactose- found in milk • Fructose- fruit sugar; VERY sweet!

  35. Carbohydrates- Disaccharides • Disaccharides- “two sugar molecules” • Sucrose- table sugar • Maltose- malt “Beer” sugar • Lactose- milk sugar

  36. Carbohydrates- Polysaccharides • Storage Polysaccharides • Starch in plants • Glycogen in animals • Structural Polysaccharides • Cellulose- major plant cell wall part • Chitin – major animal shell compound

  37. Lipids= “fats, oils, wax, steroids” • Made of 3 fatty acids + 1 glycerol • Can be saturated (have single bond). Solid at room temperature. • Ex. Butter, lard, margarine • Can be unsaturated (have double bond). Liquid at room temperature. • Ex. olive oil, vegetable oil, etc

  38. Lipids important for cells • Phospholipid bi-layer- surrounds cells • Hydrophobic “water fearing” • Fatty acid tail • Hydrophilic “water loving” • Phosphate head

  39. Lipids important for cells • Sex hormones • Estrogen, testosterone, etc Discussion: anabolic steroids Discussion: fat-soluble vitamins (Vitamins A, D, E and K )

  40. Proteins= Enzymes • Made of chains of amino acids • Do basically “everything” • Contract muscles, move oxygen, support cells, insulin to break down sugar, protect against disease, etc • End in “-ase” • Catalase, Amalase, Protease, Lactase, etc

  41. How Proteins Work • Enzymes bind to the substrate to break it apart • Enzymes speed up reaction by LOWERING the activation energy needed to start the reaction.

  42. Nucleic Acids= DNA or RNA • Made of strings of nucleotides • Nucleotides are made of • Sugar • Phosphate • Nitrogen Base (adenine, thymine, cytosine, or guanine) • Stuck together by hydrogen bonds

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