1. Chapter 2: The Chemistry of Life

2. 2-1 The Nature of Matter Key Concepts What three subatomic particles make up atoms? How are all of the isotopes of an element similar? What are the two main types of chemical bonds?

3. 2-1 The Nature of Matter Atoms Building blocks of matter Subatomic particles: protons, neutrons, electrons locationcharge protonsnucleuspositive neutronsnucleusneutral electronselectron cloudnegative

4. Atomic Structure

5. Elements and Isotopes Element-pure substance that consists entirely of one type of atom Isotope- atoms of the same element that differ in the number of neutrons they contain Key concept: Because the have the same number of electrons, all isotopes of an element have the same chemical properties

6. Radioactive Isotopes Some isotopes are radioactive = their nuclei are unstable and break down at a constant rate over time (half-life) Can give off radiation (potentially dangerous) Several uses in science Geology-rock and fossil ages Medicine-cancer treatments, bacteria killers Tracers of movements inside organisms

7. Chemical Compounds Compound-substance formed by the chemical combination of two or more elements in definite proportions Big idea: physical and chemical properties of a compound are usually very different from those elements from which it is formed! Sodium = reacts explosively in water Chlorine = poisonous greenish gas used to kill soldiers in WW1 Combined make salt! Essential for life! Ex: water, salt

8. Chemical Bonds The main types of chemical bonds are covalent and ionic bonds! Ionic Bonds Transfer(Gain or loss) of electrons Formed by ions of opposite charge Between Metals and Nonmetals RIGID, BRITTLE Ex: NaCl Covalent Bonds Sharing of electrons Structure resulting is called a molecule Between two or more nonmetals FLEXIBLE! Ex: H 2 0 Ionic is Stronger!

9. Ionic Bonding

10. Covalent Bonding

11. Van der Waals Forces Different elements have different abilities to attract electrons…so some atoms in a covalent bonds do not share electrons equally…so the rapid movement of electrons can create regions of a molecule that have tiny positive or negative charge The slight attraction between oppositely charged regions of nearby molecules Not as strong as covalent or ionic bonds

12. 2-2 Properties of Water Key Concepts Why are water molecules polar? What are acidic solutions? What are basic solutions?

13. 2-2 Properties of Water The water molecule Polarity-The uneven distribution of electrons between oxygen and hydrogen atoms

14. Hydrogen Bonds Partial positive and partial negative regions of water molecules attract each other Cohesion-attraction between molecules of the same substance (surface tension) Adhesion-attraction between molecules of different substances (capillary actions)

15. Solutions and Suspensions Mixture- a material composed of two or more elements or compounds that are physically mixed together but not chemically combined Two mixtures of water possible 1. solution 2. suspension

16. Solutions All components are evenly distributed Always a solute and solvent Solute: the substance that is dissolved Solvent: the substance in which the solute dissolves Water’s polarity allows it to dissolve both ionic substances and other polar molecules, it is THE GREATEST SOLVENT ON EARTH!

18. Suspensions Mixtures of water and nondissolved material Non polar molecules are insoluble in water…like dissolves like! Ex: blood

19. Acids, Bases, and pH The pH scale 1-14 (represents the concentration of H + (hydronium ions) in solution) Below 7 = acidic Above 7 = basic 7 = neutral

20. Acids Definition: any compound that forms H + ions in water Have high concentrations of H + ions, pH values below 7. Strong acids 1-3

21. Bases Definition: any compound that forms OH - (hydroxide) ions in water Have lower concentrations of H + ions, pH values above 7. Strong bases 11-14

22. Buffers Weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH. Example: blood pH buffering

23. 2-3 Carbon Compounds Key Concepts What are the functions of each group of organic compounds?

24. 2-3 Carbon Compounds The Chemistry of Carbon Can bond with many elements Four valence electrons Formation of single, double, or triple bonds

25. Macromolecules Many molecules are so large that they are known as macromolecules, which can have thousands or hundreds of thousands of smaller molecules! Monomer- smaller units Polymers-larger unit made up of monomers Polymerization-formation of a polymer from monomers

26. Organic Compounds: Four Main Groups 1. Carbohydrates 2. Lipids 3. Nucleic Acids 4. Proteins

27. Carbohydrates Made up of carbon, hydrogen, and oxygen in 1:2:1 ratio Living things use carbohydrates as their main source of energy. Plants and some animals also use carbohydrates for structural purposes. Sugar types Monsaccharides Glucose, fructose, ribose Disaccharides sucrose Polysaccharides Starch, glycogen. cellulose

28. Carbohydrates

29. Lipids Mostly carbon and hydrogen atoms Generally not soluble in water Categories include fats, waxes, and oils Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings. Saturated, unsaturated, polyunsaturated

30. Lipids

31. Nucleic Acids Carbon, hydrogen, oxygen, nitrogen, and phosphorous Made up of nucleotides Nucleic acids store and transmit hereditary, or genetic, information. Two Kinds: Deoxyribonucleic acid(DNA) and ribonucleic acid(RNA)

32. Nucleic Acids

33. Proteins Macromolecules containing nitrogen, carbon, hydrogen, and oxygen. Made up of amino acids Some proteins control the rate of reactions and regulate cell processes. Some are used to form bones and muscles. Others transport substances into or out of cells or help fight disease. Proteins have up to four levels of organization. 1. sequence of amino acids in a protein chain 2. a.a.’s within a chain can be twisted or folded 3. the chain can be folded 4. more than one chain can be orientated in space

34. Proteins

35. 2-4 Chemical Reactions and Enzymes Key Concepts What happens to chemical bonds during chemical reactions? How do energy changes affect whether a chemical reaction will occur? Why are enzymes important to living things?

36. 2-4 Chemical Reactions and Enzymes chemical reaction: a process that changes, or transforms, one set of chemicals into another reactants: the elements or compounds that enter into a chemical reaction products: the elements or compounds produced by a chemical reaction Chemical reactions always involve changes in the chemical bonds that join atoms in compounds

37. Chemical Reaction Example

38. Energy in Reactions Energy Changes Endothermic Absorption of energy Exothermic Release of energy Activation Energy Energy needed to get a reaction started

39. Endo or Exo?

40. Enzymes catalyst-substance that speeds up the rate of a chemical reaction By lowering a reaction’s activation energy! Enzymes speed up chemical reactions that take place in cells.

41. Enzyme Action

42. Regulation of Enzyme Activity Factors that affect the activity temperature pH