The Chemistry of Life.

Transcription

1 The Chemistry of Life

2 Atom: the smallest unit of matter Subatomic particles 1. neutron a. In nucleus b. No charge c. Weight 1dalton 2. proton a. In nucleus b. + charge c.weight 1 dalton 3. electron a. Outside nucleus b. Move at speed of light c. Have a negative charge d. Weight1/2000 of a dalton

3 Atomic Number and Weight 1. 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)

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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

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

7 Isotopes: it s all in the neutrons! 1. have same number of protons (atomic number). 2. Different number of neutrons. 3. carbon has carbon 12, carbon 13 and carbon Radioactive isotopes- the nucleus decays spontaneously, giving off particles and energy

8 Isotopes of Carbon " Isotopes of Carbon

9 1. Energy Shells a. first level can only have 2 electrons. b. second level can have 8 electrons. c. all other levels have The chemical behavior of the atom is determined by the atom s electron shell. 3. Valance Electronsoutermost shell Electron Shells

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

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

12 Chemical 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

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14 Methane: covalent bonds

15 2. All non-metals form covalent 1. glucose bonds 2. water 3. carbon dioxide 4. sucrose

16 Ionic Bonds 1.One atom steals 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

17 4. Ionic Bonding:

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

19 Water is a Major Components of Cells 1. 2/3 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

20 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.

21 . Hydrogen bonds make water cohesive (holds like to like) ex: Insects can walk on water due to surface tension

22 Water is adhesive (holds different substances) ex: molecules can move from a plant s roots to its leaves (Capillary Action)

23 Water Dissolves Many Water 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. Substances

24 Polarity-molecules with an Water is a polar molecule Only polar molecules will dissolve in water Nonpolar molecules will not dissolve in water Ex: oil electrical charge

25 Water molecules adhere to other polar molecules. water molecule Hydrogen Bonds hydrogen bond HCl

26 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

27 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.

28 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)

29 Water has a high heat of fusion, or the heat you need to take out of water to get it to solidify (freeze). Water can hold a lot of heat energy before it changes temperatures and states. A high heat of fusion means that, even if the temperature of the air changes a lot, water will shelter you or fish from those changes and provide a stable environment.

30 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.

31 ph Scale ph Scale: Based on the concentration of H + (1-14) ph of acid <7 ph of base >7 ph of neutral = 7 If blood ph is either below 6.9 or above 7.8 a person cannot survive

32 Acids and Bases Water can be broken down into acids and bases Acids- 1) high concentration of hydrogen ions. H+ 2) ph less than 7 EX: HCl

33 Acids and Bases Bases 1) Low concentration of hydrogen ions. OH- 2) ph is greater than 7 3) Also called alkaline EX: NaOH

34 ph (2) More H + More OH -

35 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 Organic Compounds

36 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

37 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

38 Carbohydrates 1.Made of carbon, hydrogen, and oxygen in a 1:2:1 ratio. 2. Key source of energy-found in fruits and vegetables. 3. Monosaccharidessingle sugars, A. the building blocks of carbs B. Ends in-ose Examples: glucose, fructose, maltose

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

40 Disaccharides and Polysaccharides 4. 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

41 Carbohydrates: Indicator Tests Simple Sugars: Benedict s solution Blue solution turns orange/green/brown Complex Carbs: Lugol s solution/ Iodine Turns from orange-redbrown to black-purple

42 Let s Draw a Glucose molecule!

43 Dehydrations synthesis: making carbohydrates

44 Taking water away to join molecules 1. Dehydrate means to take water away. 2. #1 and #4 carbon will form a bond by removing water. 3. What is left?

45 Hydrolsis- adding water to break the bonds

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

47 Lipids are made by combining two 1. glycerol A three carbon alcohol 2. 3 fatty acids types of molecules Long hydrocarbon chains. Non polar

48 Lipids: Structure Lipids are made up of Monomer (basic unit): fatty acids Polymer (chain of units): lipids Specific examples: triglycerides, phospholipids

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

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

51 Proteins: Function Build and repair muscle and tissues No pain, no gain! Enzymes- proteins that speed up chemical reactions

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

53 Proteins: Structure Proteins are made up of Monomer (basic unit): amino acids 20 different kinds!* Polymer (chain of units): protein More specifically- polypeptides Amino acids linked by peptide dipeptide

54 All Amino Acids have the same 1. 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 basic structure

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56 Let s draw an amino acid 1. draw the alpha carbon 2. put in amino group. 3. put in carboxyl group 4. Hydrogen 5. R group (variable)

57 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!

58 Proteins: Indicator Test Biuret s Solution: Turns from blue to purple if protein is present

59 Nucleic Acids: Function Stores and carries genetic information

60 Nucleic Acids: Structure Nucleic Acids are made up of Monomers (basic unit): nucleotides Polymers (chain of units): DNA or RNA

61 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. Nucleic Acids

62 DNA and RNA

63 ATP-Adenosine Triphosphate Energy currency for the cells. Cells need a constant supply of ATP to function.

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

65 Energy is needed to start a 1. Activation energythe energy needed to start a chemical reaction. 2. Chemical push! chemical reaction.

66 Enzymes help biochemical 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. reactions occur.

67 Enzymes End in ase

68 Enzymes affect specific substances.

69 1.Substrate-substance on which an enzyme acts. A. amylase- breaks starch down into glucose 2.Active Site A deep folds in the surface of the enzyme. B. substrate fits into the active site

70 Enzymes are Biological Catalysts

71 Three things that effect enzyme action. 1. amount of enzyme concentration 2. Temperature 3. ph