2. Chapter 2 The Chemistry of Life

3. 2-1 The Nature of Matter

4. Everything is made of matter. And matter comes from the elements. ______ are naturally occurring. Only 4 elements- _________(C),_______________(H), _________________ (O), and __________(N) make up 96% of a human.

5. Elements that make up living things ElementSymbol% in human body Oxygen65.0 Carbon19.5 Hydrogen9.5 Nitrogen3.3 Calcium1.5 Phosphorus1.0 Potassium0.4

6. Elements cont’d Sulfur0.3 Sodium0.2 Chlorine0.2 Magnesium0.1 IronTrace IodineTrace CopperTrace ManganeseTrace MolybdenumTrace

7. Trace Elements Even though some elements are found in very small amounts, these trace elements play a vital role in _________________________________ in all organisms.

8. Atoms- The Building Blocks of Atoms An _______________________ is the smallest part of an element. Atoms are made up of a _________________ surrounded by an ______________________.

9. The nucleus and electron cloud Nucleus is composed of subatomic particles called ________________________(+ charges) and ______________________ (no charges). The electron cloud contains _________________ (- charges) in different energy levels.

10. Protons The ____________________________ determines which element we’re talking about. The number of protons is balanced out by the number of electrons so there is _________________________ in a neutral atom. If an atom has a net charge, it has either more protons or more electrons. If more protons (overall + charge) it’s called a ________________________.

11. Electrons If there are more electrons than protons (overall – charge) it’s called an ________________________. Electrons are found in energy levels.

12. Energy Levels 1 st energy level- holds _____ electrons 2 nd energy level- holds _____ electrons 3 rd energy level- holds _____ electrons Changing levels utilizes energy. From lower to higher, __________ energy. From higher to lower, __________ energy.

13. Neutrons An element can have a _____________ ______________ and still be the same element- just a different version of it. A different number of neutrons gives each substance different ___________________. Substances with differing numbers of neutrons are called ______________________.

14. Isotopes Because they have the same number of protons and electrons, the different isotopes of a single element have the ____________________________________ Some isotopes are associated with a release of radiation (their nuclei are unstable and break down). Radiation can ________________________ (cancer treatments).

16. Is water an element? Chemical formula is H 2 O- hydrogen and water. Type of substance called a _______________. A compound is a substance composed of ________ _______________________________.

17. Compounds A compound is a substance formed by the combination of two or more elements in ________________________________ Composition is determined by chemical formula H 2 O NaCl The smallest unit of a compound is a _______________________.

18. Bonds Combined substance are held together by bonds. ___________________: two substances that share electrons. Found in most organisms (proteins, fats, carbohydrates, water). ____________________: the attractive force existing between two ions of opposite charge. (Na + and Cl - are attracted to form a neutral compound: NaCl. The ions have combined chemically.)

19. Van der Waals Forces Because electrons are moving quickly, there may be tiny _____________________ _______ charged areas on a large molecule. If shapes and charges of two molecules match, a slight attraction may develop- easily formed easily separated

21. 2-2 Properties of Water

22. The Importance of Water Most life processes can occur only when molecules and ions are free to move and collide with one another- when they are ___________ _____________________ Water is an example of a __________________. + - - + --

23. Polar Molecules A polar molecule is a molecule with an _______ ____________________ of charge, so that the oxygen end is slightly positive and the hydrogen end is slightly negative. This makes it act like a ______________________. By being polar, water can attract and dissolve many _________ compounds. + --

24. Water molecules also attract each other- the plus side to the minus side. The they can form a weak covalent bond called a _______________. __________________________: attraction between molecules of the same substance. Water is very cohesive. __________________________: Attraction between different substances (think meniscus) Other molecules with hydrogen bonds are found in _________________ (an important fact!). - - - - + +

25. Solution A solution is a mixture in which one or more substances is _________________________ in another substance. The _______________ is dissolved into the __________________. Example: Kool-aid is a solute in water, or blood sugar.

26. Suspensions Some materials don’t break into individual molecules in water but into ________________ they don’t settle out. The __________________ keeps them suspended. Example: Milk Blood

27. Mixtures A mixture occurs when two substances are mixed but ____________________________. Example- sand and sugar.

28. Acids, Bases & pH H 2 O H + + OH - Water hydrogen + hydroxide ion ion

29. Acids & Bases Chemical reactions can only occur if conditions are right, including the pH of the environment. pH is a measure of how ________________________________a solution is. Acid: any substance that forms ____________________ in water HCl (H2O) H + + Cl - Base: any substance that forms ____________________ in water NaOH (H20) OH - + Na +

30. Acids & Bases Strong acids and bases can harm living tissue. ________________ keep the pH between 6.5 and 7.5 (homeostasis). Example: buffered aspirin (ASA)

31. The pH Scale Indicates concentration of ______________. Strong acids: ____________ Strong bases: ____________ Neutral pH = 7 ____________

32. 2-3 Carbon Compounds Carbon has 4 electrons in outer energy level available to bond, so usually forms _________ _____________. C

33. Role of Carbon cont’d. Can bond with _____________________________ or with many other elements. When carbons bond to each other, can form _________ ____________________________________________ Rings or chains can have ______________________ in them as well. C C C OH N C C

34. Molecular Chains _____________________________ can contain up to 1000s of carbon atoms. Proteins in animals and starches in plants are examples of macromolecules in organisms.

35. Condensation & Hydrolysis ____________________________: molecules are bonded together by one losing an -H and the other an - OH (HOH - a water molecule!) ____________________________: the breaking apart of a molecule by adding water to it, giving an -H to one end and an -OH to the other.

36. Structure of Carbohydrates A _____________________________ is an organic compound composed of carbon, hydrogen, and oxygen with a ratio of 2 hydrogens and 1 oxygen for every carbon. ___________________: simple sugar like glucose or fructose ___________________: a two-sugar carbohydrate ___________________: polymers composed of many monosaccharide units, like starch, cellulose, or glycogen.

37. Polysaccharides __________________________: highly branched chains of glucose used as food storage by plants __________________________: another, even more branched polymer of glucose used for food storage in animals __________________________: a glucose polymer that forms the cell wall of plants and gives plants structural support.

38. Proteins  A protein is a large, complex polymer composed of ____________________________________ _____________________________.  The basic building blocks of proteins are called _______________________________.  _____________ common amino acids  Linked by condensation and a covalent bond called a __________________________.  The __________________________________ of the amino acids determines the kind of protein.

40.  Proteins are _____________________________.  Build __________________________ and carry out cell _______________________________.  Muscle contraction  Transporting oxygen in blood  Carrying out chemical reactions  Providing immunity  Enzymes

42. Lipids (Fats) Lipids are organic compounds that have a large proportion of C-H bonds and _________________________ than carbohydrates. Example: C 57 H 110 O 6 Commonly called ___________________________. They are insoluble in water because their molecules are ______________ and not attracted by water molecules. Used for long-term energy storage, insulation, and protective coatings. They are major components of cell membranes. fatty acid glycerol fatty acid fatty acid

43. Nucleic Acids  A nucleic acid is a complex macromolecule that stores information in cells in the form of a ______________.  Made of polymers of smaller subunits called _____________________________.  They consist of carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms arranges in three groups- _________________________________________________ Examples are DNA and RNA.

44. 2-4 Chemical Reactions “You are what you eat.”

45. CH 4 + 2O 2 CO 2 + 2H 2 O ___________ ____________

46. Chemical Reactions In chemical reactions Bonds between atoms are ____________________ Substances ____________ into different substances Every cell in your body has chemical reactions going on inside it.

47. Metabolism Metabolism is all of the ____________________ that take place in an organism. These reactions break down and build molecules that are important for the functioning of organisms. Chemical reactions are represented by chemical __________________________.

48. Enzymes  An enzyme is a ___________________ that speeds up a chemical reaction by lowering the _________________________________.  Might not occur at all without it.  Allow temperature to be ________________ or environment to be less acidic, for example.  Found in _______________________, synthesis of molecules, and ____________________________ ____________________________.

50. Regulation of Enzymes Enzymes are effective within a narrow range of _______________________________________ Cells have specialized proteins that turn enzymes _____________________________