Chapter 2 Chemistry of Life

Chemistry Video

Vocabulary List: Atom Nucleus Electron Element Isotope Compound Ionic bond Ion Covalent bond Molecule

Q: If you take a stick of chalk and break it in half, are both halves still chalk? YESNO atomos- unable to cut

ATOM ProtonsNeutronsElectrons + charge neutral - charge mass mass 1/1840 mass nucleus nucleus space

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

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

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:

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

Little Boy Bomb Video

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?

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?

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

LAB- are foods acidic or basic? FOODpH (A/B)

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

Nucleotides Nucleic acid Triglyceride Fat/Wax/Steroids Amino acid Polypeptide Monosaccharide Polysaccharide CarbsProtein Nucleic Acid Lipid 4 ORGANIC MOLECULES

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

Simple vs. Complex Carbohydrates

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

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

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”

-some are acidic/basic -polar/nonpolar

LAB: FOOD ANALYSIS

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 water 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)

Enzymes – catalysts or “biological wedges”

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

Enzymes: -Regulate chemical pathways -Make materials that cells need -Release energy

Dehydration synthesis- build up by removing water Hydrolysis-break down by adding water