BIOLOGY II ORGANIC CHEMISTRY UNIT

Transcription

1 BIOLOGY II ORGANIC CHEMISTRY UNIT

2 ELEMENTS AND ATOMS Matter Anything that takes up space.

3 Three classes of matter: Elements contain only 1 type of atom Compounds 2 or more elements combined in a chemical reaction. Mixture: combination of 2 or more substances each retaining its characteristic properties.

4 Matter can exist in three forms Solid Liquid Gas

5 Elements contain tiny particles called atoms. Atoms are made up of subatomic particles: Electrons Neutrons Protons

6 Atoms have an atomic mass and an atomic number. 1. Atomic mass: protons + neutrons (found in the nucleus) 2. Atomic number: # of protons (elements are arranged on the periodic chart by this number)

7 Atoms have energy levels This is when electrons are spinning in regions called shells, levels, or clouds. The most important is the outer most shell or level.

8 All atoms/compounds want 8 electrons in their outer shell octet rule (most stable). An atom will gain an e- to obtain this or will lose an e- to help another atom or compound obtain 8 e-.

9 Example: Oxygen Atomic # = 8 Always 2 e- in first shell, 6 e- in outer shell. Oxygen needs how many electrons to fill it s outer shell? 2 (This is the valence #)

10 ISOTOPES Atoms that have the same atomic number and differ only in the number of neutrons. EX: Carbon Carbon 12 Carbon 13 Carbon 14

11 Importance: Carbon 14 is radioactive. Because we know it breaks down at a specific rate, the amount of this atom remaining is used to determine the age of fossils. (Carbon Dating)

12 Radioactive materials are very valuable in the treatment and diagnosis of disease. They are injected into the body and then they show up on various scans. Example: radioactive iodine thyroid function and radioactive seeds for prostate cancer.

13 MOLECULES AND COMPOUNDS Atoms often combine with each other to form a chemical unit called a molecule. Chemical Bonding when 2 or more substances combine chemically

14 2 types Ionic Bond they donate e-. Bonds are created by an attraction between specifically charged ions. Na + Cl = NaCl (Na becomes +, Cl becomes -) Covalent Bond: bond created by the sharing of e-. H 2 + O 2 = H 2 O

15 WATER AND LIVING THINGS Water makes up 60-70% of the body weight of most organisms. (H 2 O) Properties of Water because of water s polarity and hydrogen bonding, molecules tend to cling together. This causes water to have many characteristics.

16 WATER IS LIQUID AT ROOM TEMPERATURE. Drink it, cook with it, take a bath in it. Importance: compounds like H 2 O with low molecular weights are usually gases at room temperature.

17 Hydrogen bonds keep this from occurring. Without Hydrogen bonds our body & body fluids would be gases.

18 WATER IS A UNIVERSAL SOLVENT. Water is used in many chemical reactions to dissolve materials.

19 WATER MOLECULES ARE COHESIVE AND THEREFORE LIQUIDS WILL FILL VESSELS. Water molecules cling together because of H bonds which allows water to flow freely. This allows dissolved and suspended molecules to be evenly distributed.

20 Importance: In our bodies, blood which fills our arteries and veins is 92% water. Blood transports oxygen and nutrients to our cells and removes waste such as carbon dioxide.

21 THE TEMPERATURE OF LIQUID WATER RISES AND FALLS SLOWLY PREVENTING SUDDEN AND DRASTIC CHANGES. Water protects us and other organisms from rapid temperature changes and helps us maintain a relatively constant temperature.

22 WATER HAS A HIGH HEAT OF VAPORIZATION, KEEPING THE BODY FROM OVERHEATING. Importance: Water helps moderate the Earth s temperature so life can exist. In hot temperatures we sweat.

23 FROZEN WATER IS LESS DENSE THAN LIQUID WATER SO THAT ICE FLOATS ON WATER. Importance: Water freezes from top to bottom. Aquatic animals are protected. Ice insulates the water so an entire body of water doesn t freeze.

24 ORGANIC MOLECULES Carbon is the key element in organic molecules. It combines with O, H, N, and S to get building blocks of living matter.

25 CARBOHYDRATES C N (H 2 0) N 1. Function is for quick and short term energy storage. 2. They consist of sugars and starches. 3. They only make-up 1% of body weight, but are the principal source of chemical energy for cells.

26 EXAMPLES 1. Glucose most common sugar. 2. Hexose 6 carbon sugar. 3. Cellulose found in plant cell walls.

27 B. LIPIDS FATS, OILS, WAXES, STEROIDS. LONG TERM ENERGY. 1. Lipids are insoluble in water. 2. Fats come from animals and are solid at room temperature. Includes fatty acids and glycerol. (saturated bad, monounsaturated good, polyunsaturated ok) 3. Oil comes from plants and are liquids at room temperature.

28 4. Steroids are large molecules w/ H and O atoms joined to 4 rings.

29 5. Lipids are important in cell membranes because they do not dissolve in water.

30 Demonstration emulsification.

31 C. PROTEINS 1. Made of long chains of amino acids. 2. Sequencing of amino acids determines uniqueness of proteins. 3. Found in hair + nails.

32 PROTEIN PICTURE

33 D. NUCLEIC ACID 1. Found in DNA and RNA 2. They regulate protein synthesis 3. RNA and DNA both have a phosphate sugar backbone and 4 bases.

34 DNA VS RNA DNA RNA Sugar Deoxyribose Ribose Structure Bases Comlimentary base pairings Double stranded and twisted in a helix Adenine, thymine, guanine, cytosine G-C A-T Single stranded Adenine, guanine, cytosine, uracil G-C A-U

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36 V. ENERGY A. Cells get energy through a process called cellular respiration. C 6 H 12 O 6 + O 2 CO 2 +H 2 O + energy

37 B. 4 types of chemical reactions 1. Synthesis A + B AB small molecules combine to make proteins requires energy - anabolism

38 2. Decomposition Breakdown of complex substances into simpler things. Hydrolysis when H 2 O is added to split something apart. Releases energy catabolism.

39 3. Single Replacement 4. Double Replacement

40 VI. THE PH SCALE = HYDROGEN ION CONCENTRATION A. Acids have a lot of H + ions released. B. Bases have a lot of OH - ions released. C. ph scale 0 to 14 acids 0-7, bases 7-14

41 ACIDS Battery Acid = 0.3 Gastric juice = 2.0 Lemon juice = 2.3 Vinegar = 2.8 Soft drinks = 3.0 Apples = 3.1 Rain = 6.2 Milk = 6.7

42 BASES Blood = Seawater = 8.0 Pancreatic juices = 8.5 Milk of Magnesia = 10.5 Bleach = 12.6 Drano = 13 Lye = 13.5

43 D. Acid + Base yields salt + water H + = OH - 2 NaOH + H 2 SO 4 2 H 2 O + Na 2 SO 4 Sodium Hydroxide + Sulfuric Acid yields Water and Sodium Sulfate

44 E. ELECTROLYTES 1. Things that ionize in water 2. Electrolytes carry a charge which conducts a current. ex: nerve impulses, enzyme activity

45 Bioluminesence creating light in living creatures. (fire flies, jelly fish, glow worm, fish, fungi) Why do they glow try to see, protection, attract food or a mate.

46 Glowsticks chemiluminescence