Element = one type of atom Isotope = atoms of the same element that contain different numbers of neutrons (# of electrons and protons remain constant) If the atomic mass is the sum of protons + neutrons atomic number = the # of protons which number changes in an isotope? **Marbles or colored blocks
Compound - substance formed by the chemical combination of 2 or more elements in definite proportions
Atomic Bombs Nuclear Fission (splitting) of Uranium or Plutonium Uranium (U) or Plutonium (Pu) = large & unstable (radioactive) Rapid decay rate --> Release energy needed to hold atom together Energy release = radiation Little Boy: 4 tons of fuel = 15 kilotons of TNT Nuclear Fission Video: http://www.youtube.com/watch?v=N7C14UIKuv8
Atomic Bombs continued Steps: 1. Explosion from TNT condenses all Pu atoms to “critical mass” 2. Neutron escapes (energy release) from decaying nuclei and hits another Pu atom 3. Pu atom that was hit subsequently decays (more energy release) 4. All the Pu atoms start decaying within seconds
CHEMICAL COMPOUNDS H (gas) + O (gas) H 2 O (liquid) Sodium + Chlorine NaCl (table salt) Molecule – the smallest unit of compounds whose atoms are joined by covalent bonds
Chemical bonding- involves the electrons surrounding the nucleus of each atom Ionic Bondvs.Covalent Bond Transferringvs. Sharing To do: 2 circles with 8 chairs apiece Q: How can this problem be resolved? Science question: What kind of bond is being modeled?
Water = 50-60% of your body weight Higher if you have more muscle Function: Transport of nutrients and oxygen via bloodstream Transport white blood cells to fight infection via lymphatics Rid body of waste Normal level of H2O loss = 2.5L 350mL through lungs 100mL through sweating 350mL through skin 1000-2000mL through kidneys
H2OH2O An oxygen atom has 8 protons Each hydrogen atom has 1 proton Polar molecules have an uneven distribution of electrons 10 protons = 10 shared electrons But will one part of the compound have a greater pull on those electrons? Yes/No…..why?
2 polar ends attract each other A weak bond between the H of one atom and the O of another in water (or any electroneg…) H 2 0 can hydrogen bond with 4 other H 2 0 molecules hydrogen bonding - the attraction between water molecules
Properties of Water Universal Solvent- due to its polarity -Salts, sugars, acids, bases -Hydrophobic vs hydrophilic
Liquid Water Solid Water (Ice) http://expertvoices.nsdl.org/polar/2009/02/03/teaching-about-snowflakes-a-flurry-of-ideas-for-science- and-math-integration/ http://cc.oulu.fi/~nmrwww/comp_res4.html Water Expands When It Freezes Water becomes less dense due to hydrogen bonds forming between the water molecules, which line up molecules less efficiently (in terms of volume) when water is frozen.
DRILL- need to have read 1) Draw a molecule of water, indicating its polarity. 2) Explain the truth of the statement: Water can be considered the universal solvent due to its polarity WE NEED A BREAK! Outside…
Dehydration synthesis- build up by removing water Hydrolysis-break down by adding water
Mixture – composed of 2 or more elements/compounds that are mixed physically but not chemically combined 1)Solution – the components are evenly distributed with the solute dissolved in the solvent ex: salt water 2) Suspension – mixture of water and nondissolved material ex: blood is both a suspension (cells) and solution
Acids, Bases and pH pH scale – a measure of the H + concentration in solution
Lower ph = more H + Higher ph = fewer H + Acid-any compound that forms H + in solution (HCl in the stomach = pH 2.5) Base-any compound that produces OH- in solution (bleach = pH 12.5) ***Pure water is always neutral H 2 O H + + OH - in equal amounts
Organic Molecules- study of all compounds that contain bonds between CARBON atoms methane isooctane **C-C bonds allow for long chains…Large and complex structures! **4 valence electrons…binds with many other elements
MACRO molecules- giant molecules polymerization polymers monomers- may be identical/repeating or different
CARBOHYDRATES Ends in –ose General formula C 1 :H 2 :O 1 Carbohydrate – “carbon hydrate” when CO 2 reacts with water to form glucose major source of ENERGY for all living organisms source of structural support (plants) Monosaccharide ex. glucose, fructose and galactose Disaccharide ex. Lactose, sucrose Polysaccharide ex. Gycogen, starch and cellulose
A.Starch 1. stored energy for the plant 2. starch in potatoes, refined wheat and white products are quickly converted into glucose in the body B.Cellulose 1. major component of plant cell walls 2. does NOT provide energy nor is it digested by our bodies 3. called fiber in our diets & is critical for a healthy digestive system C.Glycogen 1. animal starch 2. stored form of glucose in our bodies 3. stored in liver to remove glucose from the blood And your resident dietician says…………why?
LIPIDS Not a polymer- all lipids are grouped together because hydrophobic- “scared of water”/ little or no affinitiy for water ex. You will see oil separate from vinegar in salad dressing
A.Fats 1. Greasy, oily or waxy to the touch 2. Can be solid or liquid at room temperature 3. If excess calories are consumed, excess stored as fat 4. Stores vitamins and other chemicals 5. Form of insulation for the organism B. Phospholipids -membranes in & around the cells C. Waxes 1. Keep oganism or parts or organisms waterproof & protected 2. Ear was, wax on duck feather D. Steroids 1. Cholesterol a. important component of cell membranes b. harmful if too much in the diet or bloodstream 2. Hormones a. estrogen, progesterone and testosterone control reproductive function b. Anabolic steroids – illegally used to build up muscles - cause serious damage to hear, liver and kidneys
And your resident dietician says………… EXTRA CREDIT: Describe these terms in detail & provide examples: saturated fat unsaturated fat Due: next class
PROTEINS Amino acid – monomer Made up different combinations of 20 amino acids a. 12 nonessential amino acids b. 8 essential amino acids Complete proteins-contain all 8 essential amino acids ex. Meat, eggs, dairy products, fish and tofu Vegetables have some but not all a. must be eaten in combination b. complementary foods (rice and beans) – together provide a complete protein Cells recombine aa to build the proteins necessary for function
Protein Function Movement Growth and Repair NOT for energy Structure Biochemical Control Defense Protein = “first or primary”
BOGGLE When the timer begins, try to construct as many words as possible using the given letters. You may go in any direction, but not diagonally. Think & write quickly!!!
NUCLEIC ACIDS Nucleotide - monomer; - phosphate group, 5 carbon sugar and nitrogenous base Nucleotides covalently bind to form a nucleic acid Nucleic acids store and transmit genetic information 4 Types of nucleotides (A-T/U-C-G) = endless # of different molecules 2 Types of Nucleic Acids = DNA and RNA
What do baking soda, vinegar and water have to do with Biology? Beaker 1 5 mL baking soda 120 mL water Beaker 2 5 mL vinegar 120 mL water Beaker 3 5 mL baking soda 5 mL vinegar Chemical reaction – a process that changes or transforms one set of chemicals into another
ReactantProducts Activation Energy – the necessary energy input to jumpstart a reaction but…..the formation of carbonic acid is slow and the CO 2 would build up too quickly in the bloodstream…… CO 2 + H 2 OH 2 CO 3 (carbonic acid)
DRILL 1)Define activation energy? 2)How is an enzyme a catalyst i.e. how does it relate to activation energy? 3)What are the substances that are transformed in a chemical reaction called? HW: Read Section 2-4 in your textbook and answer questions 9, 10, 22-25, 27, 28 and 33 on pages 57-58 (end of chapter assessment)
ENZYMES Usually ends in –ase (with 1 st derived from the reaction it catalyzes) Works as a 1 enzyme:1 reaction-VERY specific (shape?) Enzymes provide a site where reactants can be brought together Substrates - reactants in an enyzme-catalyzed reaction Active site- site of substrate binding on the enzyme -complementary in “lock & key” style
How Enzymes Work 1.Reactants, called substrates, bind to specific enzymes; the site where enzymes bind is called the active site 2.Once the substrate binds to the active site, it changes shape and forms the enzyme- substrate complex 3.The substrates react to form new products; the enzyme-substrate complex helps to break and form bonds