Presentation on theme: "QOD: In a group of 4, each pick one paragraph of the article to read. (note: paragraph 2 is the hardest one, the back page will be more helpful) When."— Presentation transcript:
1QOD:In a group of 4, each pick one paragraph of the article to read. (note: paragraph 2 is the hardest one, the back page will be more helpful)When you are done reading, discuss as a group and try to answer the question: Why does the doctor not recommend the use of external cooling (such as ice baths, cold water or even air conditioners) to reduce a fever.
2Chemistry as it related to biology 2.1 Chemical ElementsChemistry as it related to biology
9IsotopesIsotopes are atoms with the same number of protons but differ in number of neutrons; e.g., a carbon atom has six protons but may have more or less than usual six neutrons.
10Carbon 14 - Break it Down!Carbon- 12 is the most common form of carbon, it has 6 protons, 6 electrons, and 6 neutronsIt is called Carbon 12 because that is its weight (6 + 6 )Carbon 14 has 2 extra neutrons, its weight is 14 (6 + 8 ); it is an isotope of carbon
11A carbon with eight rather than six neutrons is unstable; it releases rays and subatomic particles and is a radioactive isotope.Sample Question: A 200 g sample of muskopfonian is left in a container , the half life of muskopfonian is 1 hour. How much of the sample will be left after 4 hours?Answer:200 x .5 = 100 (hour 1)100 x .5 = 50 (hour 2) 50 x .5 = 25 (hour 3) 25 x .5 = 12.5 (hour 4)or 200 x .54 = 12.5
12Low levels of radiation such as radioactive iodine or glucose allow researchers to trace the location and activity of the atom in living tissues; therefore these isotopes are called tracers which are used in CAT scans
13 High levels of radiation can cause cancerous tissues and destroy cells; careful use of radiation in turn can sterilize products and kill cancer cells.
14Pick your favorite element from the table Pick your favorite element from the table. Turn and tell your lab partner what it is, how many protons, electrons and neutrons it has, and what it's atomic weight is.
15S orbital: innermost, hold 2 elections E. Electrons and Energy 1. Electrons occupy an orbital at some level near or distant from the nucleus of the atom.S orbital: innermost, hold 2 electionsP orbital: after s, holds 8 elections
163. When atoms absorb energy during photosynthesis, electrons are boosted to higher energy levels. 4. The innermost shell of an atom is complete with two electrons; all other shells are complete with eight electrons.5. The outermost shell is the valance shell, and the number of valance e- in the outermost shell determine many of the atoms properties
17DRAW IT! QUICK!! 1. Draw six protons in the nucleus of the atom. 2. Draw six neutrons in the nucleus of the atom.3. Draw two electrons in the first energy level and label them with their charge.4. Draw four electrons in the second energy level and label them with their charge.5. What element is it!? __________ (the future of the human race depends on it!)
192.2 Elements and Compounds Compounds: When two or more different elements react or bond together, they form a compound (e.g., H2O). Electrons possess energy and bonds that exist between atoms in molecules contain energy.Glycine
20B. Ionic BondingIonic bonds: when electrons are transferred from one atom to another.Attraction of oppositely charged ions holds the two atoms together in an ionic bond.Losing or gaining elections gives ions a filled outer shell, so they are more stableEx: sodium (Na+) and Chlorine (Cl- ) make NaCl
21Cation:positively charged ionanion:negatively charged ion
23C. Covalent Bonding Strongest type of bond Covalent bonds: when two atoms share electrons so each atom has octet of electrons in the outer shell.Hydrogen can give up an electron to become a hydrogen ion (H+) or share an electron with another atom to complete its outer shell of two electrons.Strongest type of bond
24Structural formulas represent shared atom as a line between two atoms; e.g., single covalent bond (H-H), double covalent bond (O=O)Carbon has amazing bonding properties, as we will learn in the next chapter on BIOCHEMISTRY
25Bonds can be represented using structural formation, where a line represent the sharing of 2 elections
26In nonpolar covalent bonds, sharing of electrons is equal = no charge D. Nonpolar and Polar Covalent BondsIn nonpolar covalent bonds, sharing of electrons is equal = no chargeWith polar covalent bonds, the sharing of electrons is unequal. = chargeEx: water molecule (H2O), sharing of electrons by oxygen and hydrogen is not equal; the oxygen atom with more protons dominates the H2O association. *The oxygen then assumes a small negative charge *
27Hydrogen bonds create surface tension. Hydrogen Bond: weak attractive force between slightly positive hydrogen atom of one molecule and slightly negative atom in another or the same molecule.Weakest bondmainly between O, N, F and an atom of hydrogenMany hydrogen bonds taken together are relatively strong.Hydrogen bonds between complex molecules of cells help maintain structure and function.Hydrogen bonds create surface tension.
28Van der Waals Interactions When you have a molecule which is electrically dipolar (equal but opposite in charge) you have attraction between the negative pole of one molecule and positive pole of the other molecule. They are usually weaker than hydrogen bounds but exist in all matter
29Notice the e- spend more time around the oxygen molecule: it’s has more protons to attract the elections*the shape allows for one side to be more + and the other more -
30Biological molecules recognize and interact with each other with specificity based on their shape
31Title: Properties of water In your notebook, create a chart listing the properties of water, and why each property is important. Include example whenever possibleuse pages 29-31
32water 1. High Specific Heat 2. High heat of vaporization Examples of chartsPropertyExplanationImportanceExample1. High Specific Heat2. High heat of vaporization3. Universal solvent4. Cohesive and Adhesive5. Ice FloatswaterProperty 1Property 2Property 3Property 4Property 5ExplanationPg 29-31example
331. All living things are 70.90% water. 2.3. Chemistry of WaterA. Facts1. All living things are 70.90% water.2. Because water is a polar molecule, water molecules are hydrogen bonded to each other. 3. With hydrogen bonding, water is liquid between 0 C and 100 C which is critical for life.
34B. Properties of WaterHigh Specific Heat: The temperature of liquid water rises and falls more slowly than that of most other liquids.a. Calorie is amount of heat energy required to raise temperature of one gram of water 1o C. b. Because water holds more heat, its temperature falls more slowly than other liquids; this protects organisms from rapid temperature changes and helps them maintain normal temperatures.
352. Water has a high heat of vaporization. a. Hydrogen bonds between water molecules require a large amount of heat to break. b. This property moderates earth's surface temperature; permits living systems to exist here. c. When animals sweat, evaporation of the sweat takes away body heat, thus cooling the animal.
36Heat of vaporization Evaporative cooling Organisms rely on heat of vaporization to remove body heat
373. Water is universal solvent, and facilitates chemical reactions both outside of and within living systems..a. Water is a universal solvent because it dissolves a great number of solutes. b. Ionized or polar molecules attracted to water are hydrophilic. c. Nonionized and nonpolar molecules that cannot attract water are hydrophobic.Solvents dissolve other substances (solutes) and do not lose their own properties.If we use a simple and easy example, we can get a handle on the idea. Take a glass of warm water, put a teaspoon of table salt in it, and stir it. The salt will dissolve in the water and "disappear" from view. The water is the solvent here, the salt is the solute in this example, and the resulting salt water is a solution that we created. It's that simple.
384. Liquid water is cohesive & adhesive Cohesion = H bonds between water molecules; H2O molecules tend to stick together.Adhesive= ability of water to cling to other polar moleculesimportance= Higher surface tensionTransport H2O against gravity in plants
395. Ice floatsMost (all?) substances are more dense when they are solid, butnot water… Ice floats!H bonds form a crystalallowing life to survive the winterIce! I could use more ice!Most (all?) substances are more dense when they are solid, but not water…Lower density as a solid = Ice floats!H bonds form a crystalAnd this has made all the difference!
41Buffers & cellular regulation pH of cells must be kept ~7Buffers are solutions used to stabilize the pH of a solutionControl pH by using buffersreservoir of H+donate H+ when [H+] fallsabsorb H+ when [H+] rises123456789Amount of base addedBufferingrangepHExercise = acidic in musclesCO2 = carbonic acidlactic acidbody uses buffers to counter act this
42BICARBONATE BUFFER SYSTEM: H2O + CO2 H2CO3 HCO3 -+ H+HCO3- = Bicarbonate (weak base)H2CO3 = Carbonic acid (weak acid)Major buffer system in bloodMaintains blood pH between 7.38 and 7.42
43C. Acids and Bases1. Covalently bonded water molecules ionize; the atoms dissociate into ions.2. When water ionizes or dissociates, it releases a small (107 moles/liter) but equal number of H+ and OH ions; thus, its pH is neutral. 3. Water dissociates into hydrogen and hydroxide ions:
44Acid molecules dissociate in water, releasing hydrogen ions (H+) ions: HCl ¨ H+ + Cl-. Bases are molecules that take up hydrogen ions or release hydroxide ions. NaOH ¨ Na+ + OH-.See also: Acid & Base Coloring
456. The pH scale indicates acidity and basicity (alkalinity) of a solution. 1) One mole of water has 107 moles/liter of hydrogen ions; therefore, has neutral pH of 7. 2) Acid is a substance with pH less than 7; base is a substance with pH greater than 7. 3) As logarithmic scale, each lower unit has 10 times the amount of hydrogen ions as next higher pH unit;* Buffers keep pH steady and within normal limits in living organisms..
46Acids Base Substances with hydrogen ions (H+) Taste sour Chemistry in BiologyAcidsBaseSubstances with hydrogen ions (H+)Taste sourpH lower than 7Substances with hydroxide ions (OH–)Taste bitterFeel slipperypH greater than 7ExamplesStomach acidCitrus fruit: orangevinegarExamplesSoapBaking sodaCleaning products
47Create a Venn Diagram Comparing Acids and Bases Stomach acidCitrus fruit: orangeSoapCleaning productsBaking sodavinegarSubstances with hydrogen ions (H+)Substances with hydroxide ions (OH–)Taste sourTaste bitterFeel slipperypH greater that 7pH lower that 7Neutral = pH of 7
48H+ Ion Concentration Examples of Solutions pH 10 times less H+ 10–1H+ IonConcentrationExamples of SolutionsStomach acid, Lemon juice1pH100Hydrochloric acid10–2210–3Vinegar, cola, beer310–4Tomatoes410–5Black coffee, Rainwater510–6Urine, Saliva610–7Pure water, Blood710–8Seawater810–9Baking soda910–10Great Salt Lake1010–11Household ammonia1110–12Household bleach1210–13Oven cleaner1310–14Sodium hydroxide14pH Scaletenfold change in H+ ionspH1 pH210-1 10-210 times less H+pH8 pH710-8 10-710 times more H+pH10 pH810-10 10-8100 times more H+In pure water only 1 water molecule in every 554 million is dissociatedtenfold change in H+ ionspH1 pH210-1 10-210 times less H+pH8 pH710-8 10-710 times more H+pH10 pH810-10 10-8100 times more H+
511. The only atom that has a nucleus with no neutrons is _________. A) argonB) carbonC) oxygenD) hydrogen2. Which of the following elements is NOT one of the six that make up 98% of most organisms' body weight?A) hydrogenB) nitrogenC) carbonD) iron
52Which of the following statements is true? A) All isotopes give off subatomic particles.B) All isotopes are radioactive.C) All isotopes have the same number of protons.D) All isotopes have the same number of neutrons.What type of bond is formed when atoms share electrons?A) ionicB) covalentC) hydrogen
53The three isotopes of carbon 12C, 13C and 14C have different numbers of _______? A) electronsB) protonsC) neutronsThe combined number of ___________ will determine the number of electrons in orbital(s) around a neutral atom.A) orbitalsB) neutronsC) bondsD) protons
54If an atom has an atomic number of 17 and an atomic mass of 35, the number of neutrons in its nucleus equals _____.A) 17B) 18C) 52Which bond is most easily broken?A) a hydrogen bondB) a triple covalent bondC) a single covalent bond
55Which of the following statements is true? A) There are two polar covalent bonds in water.B) There are two ionic bonds in water.C) There is one ionic and one covalent bond in water.D) Electrons are less attracted to oxygen than hydrogen.The two parallel strands of DNA are held together by _______ bonds.A) nonpolarB) hydrogenC) ionicD) covalent
56The calcium ion (Ca2+) _____. A) has accepted two protonsB) has given away two electronsC) will form a covalent bond with the chlorine ion (Cl-)D) All of theseHydrogen bonds form when ___________.A) atoms share electronsB) a slightly negative atom is attracted to a slightly positive atomC) atoms gain electronsD) atoms lose protons
57Which of the following has a basic pH? A) lemon juiceB) milk of magnesiaC) tomatoesD) hydrochloric acidAquatic living things are able to survive the winter thanks to which property of water?A) It is less dense as a solid than as a liquid.B) It is cohesive and adhesive.C) It is the universal solvent.D) It resists changes of state (from liquid to ice or liquid to steam).
58Hydrophobic molecules tend to be _________. A) nonpolarB) inorganic mineralsC) ionicD) water soluble