1 The Chemistry of Life 1

2 Atom: the smallest unit of matterSubatomic particles 1. neutron a. Inside nucleus b. Neutral charge 2. proton b. + charge 3. electron a. Outside nucleus b. Move at speed of light c. Have a negative charge 2

3 Atomic Number and Weight1. atomic number- number of protons in nucleus 2. atomic weight- number of protons plus neutrons in the nucleus of the atom (a.k.a. -mass number) 3

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5 How many neutrons are in an atom?Subtract the number of protons from the mass number to get the number of neutrons Mass number – atomic number = # of neutrons 5

6 Find the atomic number, atomic mass, and # of protons, electrons and neutrons of the following elements. Atomic # Mass # # protons # electrons # neutrons Carbon Hydrogen Oxygen 6

7 Electron Shells 1. Energy Shellsa. first level can only have 2 electrons. b. second level can have 8 electrons. c. all other levels have 8. 2. The chemical behavior of the atom is determined by the atom’s electron shell. 3. Valance Electrons- outermost shell 7

8 Problem? All atoms want to have their valance electron shells full!I wish I could be a noble gas! 8

9 Chemical Bonds 1. Making of chemcial bonds Stores Energy.2. The breaking of chemical bonds Releases Energy Blah blah balh Sdf 9

10 Covalent Bonds 1. Covalent bond -The sharing of a pair of valance electrons by two atoms. 2. Bewteen two nonmetals 3. Can form single, double and triple bonds 10

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12 Methane: covalent bonds12

13 2. All non-metals form covalent bonds1. glucose 2. water 3. carbon dioxide 4. sucrose 13

14 Ionic Bonds 1.One atom transfers electrons from another to complete its outer shell. Between a metal and nonmetal Example: NaCl Because one atom has lost an electron (Na) it has now has an overall charge of +1 Because the atom that took the electron (Cl) now has an extra electron, its overall charge is -1 14

15 4. Ionic Bonding: 15

16 In a polar covalent bond Electrons are shared unequally between atoms, creating a polar molecule (–) (+) O H (–) (+)

17 Strength of Bonds Covalent > Ionic > Hydrogen

18 Water is a Major Components of Cells2/3 of all molecules in the body (all your cells are surrounded by water) 2. Water stores heat efficiently. a. sweating- helps release heat b. helps maintain homeostasis by regulating temperature 18

19 Properties of Water 1. Water is the solvent of life (universal solvent) - Polar solutes dissolve when water molecules surround them, forming aqueous solutions 2. Water is less dense as a solid than a liquid. Ice floats on water. (Ex. Glacier)

20 . Hydrogen bonds make water cohesive (water sticks to water)ex: Insects can walk on water due to surface tension (cohesion of water molecules at the surface of a body of water)

21 Water is adhesive (water sticks to other substances)ex: molecules can move from a plant’s roots to its leaves (Capillary Action); water moves up a straw

22 Water Dissolves Many SubstancesWater is the solvent. What it is dissolving is called the solute. Solution- mixture in which one or more substances is evenly distributed. Solute and Solvent together make a Solution. 22

23 Polarity-molecules with an electrical chargeWater is a polar molecule Only polar molecules will dissolve in water Nonpolar molecules will not dissolve in water – Ex: oil 23

24 Hydrogen Bonds + - + + + - - + - + + + - - + + +Water molecules adhere to other polar molecules. Hydrogen Bonds + - water molecule + + + - - + - + + + - Water molecules adhere to other polar molecules. The broken line between a water molecule and HCl represents a hydrogen bond. - HCl hydrogen bond + + + 24

25 Hydrogen Bond 1. Occurs when an atom of hydrogen has a strong attraction to two atoms instead of one 2. The atoms must be highly electronegative (electron loving) like Oxygen, Flourine, Nitrogen, Chlorine and Bromine

26 Water has high specific heat.Specific Heat is the amount of energy required to change the temperature of a substance. It allows for moderation of climate and helps organisms regulate body temperature.

27 Water has a high heat of vaporization (the amount of heat required to convert liquid water into gaseous water, aka steam). This makes it an effective coolant for the body. That is why sweating actually cools us down. (Evaporative Coolant)

28 Water has a high boiling point (100 degrees Celsius)and low freezing point (0 degrees Celsius) Water has a neutral pH. Which makes is a good buffer. A buffer is a substance that helps to moderate any changes in pH that result from the addition of acids or bases.

29 pH Scale pH Scale: Based on the concentration of H+ hydrogen ions(1-14) pH of acid <7 (1 – 6.9) pH of base >7 (7.1 – 14) pH of neutral = 7 If blood pH is either below 6.9 or above 7.8 a person cannot survive.

30 Acids and Bases Water can be broken down into acids and bases Acids-1) high concentration of hydrogen ions (H+); low concentration of hydroxide ions (OH-). 2) pH less than 7 EX: HCl 30

31 Acids and Bases Bases – 1) High concentration of hydroxide ions (OH-); low concentration of hydrogen ions (H+) 2) pH is greater than 7 3) Also called alkaline EX: NaOH 31

32 pH (2) More H+ More OH- 32

33 Organic Compounds Contain carbon - usually bonded to oxygen, hydrogen, and other carbon atoms. Most of the matter in your body is organic! These are compounds that usually come from organisms 33

34 Macromolecules Cells and their organelles are made up of smaller building blocks called macromolecules. There are 4 basic types of macromolecules. They are: Lipids Proteins Carbohydrates Nucleic Acids

35 Monomers & Polymers Macromolecules are actually made up of even smaller subunits. Each subunit of a macromolecule is called a monomer. The macromolecules themselves are called polymers, because they are made up of many of these subunits. Monomer: one basic unit or subunit Polymer: a chain of many basic units

36 Carbohydrates 1.Made of carbon, hydrogen, and oxygen in a 1:2:1 ratio.2. Key source of energy (sugar) -Found in fruits and vegetables. 3. Monosaccharides- single (one) sugars, A. the building blocks of carbs B. Ends in-ose Examples: glucose, fructose, maltose 36

37 Monomer (basic unit) : Simple sugarsor monosaccharides EX: glucose Polymer (chain of units): Complex carbohydrates or polysaccharides EX: starch, cellulose, chitin, glycogen

38 Disaccharides and Polysaccharides4. Disaccharides- two sugars glucose + fructose = sucrose 5. Polysaccharides -a. macromolecule made of many sugars. -b. storehouse for energy Excess Energy is stored as: -c. starch-in plants d. glycogen- in animals e. cellulose-found in plant cell walls 38

39 Carbohydrates: Indicator TestsSimple Sugars: Benedict’s solution Blue solution turns orange/green/brown Complex Carbs: Lugol’s solution/Iodine Turns from orange-red-brown to black-purple

40 Let’s Draw a Glucose molecule! 40

41 Lipids- are nonpolar Fats, phospholipids, oils, steroids(cholesterol) and waxes. Fats are lipids that store energy for long term, make up the cell membrane (phospholipds), provide cell structure, provide insulation 41

42 Lipids are made by combining two types of molecules1. glycerol A three carbon alcohol 2. 3 fatty acids Long hydrocarbon chains. Non polar The combining of these two molecules makes a trigylceride. 42

43 Lipids: Structure Lipids are made up of…C,H,O Monomer (basic unit): fatty acids Polymer (chain of units): lipids Specific examples: triglycerides, phospholipids

44 Lipids: Fats Saturated vs. UnsaturatedStructural formula of a saturated fat molecule Structural formula of an unsaturated fat molecule Oleic acid, an unsaturated fatty acid Stearic acid, a saturated fatty acid cis double bond causes bending (a) Saturated fat (b) Unsaturated fat 44

45 Lipids: Indicator TestPaper Bag Test: Smear substance onto paper bag If see-thru, it contains lipids

46 Proteins: Function Build and repair muscle and tissues“No pain, no gain!” Enzymes- proteins that speed up chemical reactions by lowering the activation energy. Most enzymes end in –ase.

47 Proteins Made of chains of amino acids There are 20 known amino acidsThese 20 amino acids are found in all biological species. Collagen-protein found in skin Hemoglobin, blood clots, and muscles. 47

48 Proteins: Structure Proteins are made up of…C,H,O,N Monomer (basic unit): amino acids 20 different kinds!* Polymer (chain of units): protein More specifically- polypeptides Amino acids linked by peptide bonds dipeptide

49 All Amino Acids have the same basic structure1. alpha carbon- makes center of amino acid 2. amino group 3. Carboxyl group- this is an acid 4. a single hydrogen 5 . Variable group-R There are 20 R groups Therefore there are 20 different amino acids in all living things 49

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51 Let’s draw an amino acid1. draw the alpha carbon 2. put in amino group. 3. put in carboxyl group 4. Hydrogen 5. R group (variable) 51

52 Proteins: Structure Proteins have complex structures. The shape of a protein determines its function! The levels of protein structure are: Primary structure: polypeptide chain Secondary structure: polypeptides in coils or sheets Tertiary structure: coils or sheets form a tangle Quaternary structure: more than one tangle combine to make a very complex protein!

53 Enzyme + Substrate = Product

54 Substrate The substance (reactant) an enzyme acts on. It specifically fits into the enzyme. Enzyme Substrate

55 Active Site Where the substrate and the enzyme fit together and bind to activate the enzyme. Enzyme Substrate Active Site

56 Enzymes Are specific for what they will catalyze End in -ase

57 Enzymes are specific, like a lock & key

58 Enzyme – Substrate Complex

59 Enzymes are Biological Catalysts 59

60 Enzymes affect specific substances. 60

61 Energy is needed to start a chemical reaction.1. Activation energy- the energy needed to start a chemical reaction. 2. Chemical push! 61

62 Enzymes help biochemical reactions occur.A. allows reactions to occur quickly and at low temperatures. B. increases the speed of chemical reactions. C. most are proteins. D. act as catalysts-reduce the amount of activation energy required. E. helps maintain homeostasis. 62

63 Three things that effect enzyme action.1. amount of enzyme concentration 2. Temperature 3. pH 63

64 Proteins: Indicator TestBiuret’s Solution: Turns from blue to purple if protein is present

65 Nucleic Acids: FunctionStores and carries genetic information

66 Nucleic Acids: StructureNucleic Acids are made up of… Made up of C,H,O,P, N. Monomers (basic unit): nucleotides Polymers (chain of units): DNA or RNA

67 Nucleic Acids Made of nucleotides. Made of nucleotides. Nucleotides contain a sugar, phosphate and a nitrogen base. DNA-double stranded and makes up chromosomes RNA-single stranded, used in making proteins. 67

68 DNA and RNA 68

69 ATP-Adenosine TriphosphateEnergy currency for the cells. Cells need a constant supply of ATP to function. 69

70 Organisms Need Energy for Life ProcessesEnergy- the ability to move or change matter. A. Energy is stored and released by chemical reactions. B.Reactants and products Chemical reaction absorb and release energy 1.Freezing water releases energy 2.Melting ice absorbs energy 70

71 ATP ATP = ENERGY ATP has 3 phosphates, a sugar (ribose), and adenineEnergy is released when the 3rd phosphate bond breaks. This leaves ADP and a “free phosphate.”

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73 ATP – ADP Cycle ADP joins together with a free phosphate gained through energy from food. This makes ATP. 2. Then ATP releases energy for cells by breaking the 3rd phosphate which makes ADP and a free phosphate.