Atomic Structure, Chemical Bonds, and Chemical Reactions

1. Chemistry Chapter 2

2. Atomic Structure Particles Charge Mass Proton +1 1 amu Neutron no charge 1 amu Electron - 1 0 amu

3. Chemical Bonds Ionic bonds: electrons are transferred Cation + Anion – Covalent bonds: electrons are shared Polar (slight charge) Nonpolar (no charge) Hydrogen bonds: (weak intramolecular bonds)

4. Synthesis Decomposition Single Displacement Double Displacement Hydrolysis Dehydration A + B  C C  A + B AB + C  AC + B AB + CD  AD + CB H2O + C A + B A + B – H2O  C Chemical Reaction

5. Energy Transfer • Endothermic / Endergonic – Absorption of energy • Exothermic / Exergonic – Release of energy

6. Rate of Reaction • Temperature – increase in temperature leads to an increase in kinetic energy (faster moving particles) • Particle Size – increased surface area allows particles to collide more frequently. • Concentration – the more concentrated a solution is, the more likely the particles will collide. • Catalysts – (enzymes) – help by lowering the amount of energy needed for a reaction to proceed. (not used up during the rxn)

7. Acids and Bases • pH scale (0 – 14) (measures the hydrogen ions in a soln) • Acid (sour taste; corrosive) • molecule capable of releasing H+ • molecule that absorbs a OH- • Base (bitter taste; slippery) • molecule capable of absorbing H+ • molecule that releases a OH- • Titration – balancing acid and base

8. Salts • Formation of a salt • HCl + NaOH –> H2O + NaCl • Salt is an ionic compound that contains cations other than H+ and anions other than OH-

9. Buffers • Buffer - a substance that either releases or absorbs H+ and helps to prevent a drastic change in pH. • When the buffer runs out the pH will again begin to fall with the addition of more H+.

10. Carbohydrates Monosaccharides – simple sugar (single chain or ring) ex: glucose, galactose, fructose Disaccharides – double sugar ex: sucrose, lactose, maltose Polysaccharides – many sugars ex: starch, glycogen, cellulose,

11. Lipids • Fats, Oils, Waxes • Higher number of C – H bonds than carbohydrates • Used for Lubrication, Waterproofing, Insulation, Energy Storage • Saturated vs. Unsaturated • Phospholipids, Steroids, Triglycerides

12. Proteins • Composed of 20 different amino acids. (vary by the side chain: R-group) • What makes one protein different from another is the amino acids making it up and the order of the amino acids. Each amino acid has an amine group (-NH2) and a carboxyl group (-COOH)

13. Protein Formation Peptide bond formation: long chains of amino acids joined by a dehydration reaction Proteins are classified based on function. • Folding of proteins creates different structures: primary, secondary, tertiary, quaternary Proteins can form bonds with themselves or other proteins

14. Protein Classification 2 ways of classifying proteins Structural Protein – fibrous proteins; composed of intertwined chains, resembles a rope, used for support, insoluble (ex: collagen) Functional Proteins – globular proteins; compact and spherical, water soluble, chemically active, mobile (ex: antibodies, enzymes, and protein-based hormones)

15. Protein Denaturation Denaturing – heat or pH effects hydrogen bonds in a globular protein and can permanently change it Denaturation destroys active sites ex: hemoglobin becomes unable to bind and transport oxygen when blood pH is too high

16. Molecular Chaperones • Globular proteins that prevent incorrect folding, help move certain ions across cell membranes, break down damaged/denatured proteins, etc. • Ex: stress proteins- produced in response to traumatizing stimuli

17. Enzymes • Globular proteins that act as catalysts • They regulate and accelerate biochemical reactions • Each enzyme is chemically specific

18. Nucleic Acids • DNA • Found in the nucleus • Blueprint of life (CGAT) • Inheritable • RNA • 3 types • mRNA (messenger) • tRNA (transfer) • rRNA (ribosomal) • Single Stranded • Uracil replaces thymine • ATP • Adenosine triphosphate • energy