1. CHEMISTRY OF LIFE
Chapter 2

2. Levels of Chemical Organization
Matter – anything that occupies space and has mass
Molecules – particles of matter made up of atoms
Atoms – protons, neutrons, electrons

3. A Model Of The Atom

4. Atomic number is equal to the number of protons
Atomic mass is equal to the number of protons plus neutrons

5. Isotopes Same atomic number but different atomic mass

7. Compounds

8. CHEMICAL BONDING
Ionic bond – strong electrical attraction between ions that bare opposite electrical charges - ionic molecules dissolve easily in water (dissociate)
Covalent bond – bond formed between two atoms that share a pair of electrons

9. Ionic Bond

10. Covalent Bond

11. Polar vs. Nonpolar Covalent Bonds
Polar Covalent Bond – electrons are not shared equally (ex. H2O)
Non Polar Covalent Bond – electrons are shared equally (ex. C-H)

12. Polar Covalent Bond

13. Hydrogen Bonding
Hydrogen Bond – a weak electrical attraction between the partial positive charge of one water molecule and the partial negative charge of another water molecule

14. Inorganic Chemistry
Molecules that generally do not contain carbon; there are no C-H or C-C bonds; smaller than organic molecules
H2O is an inorganic molecule – “universal solvent”
Organisms are composed mainly of water

15. Dehydration Synthesis – chemical reaction in which 2 molecules become covalently bonded by removing –H from one and –OH from another, removed atoms form water

16. Hydrolysis – the breaking apart of a molecule into its monomer subunits by the addition of the components of a H2O molecule into each of the covalent bonds linking the monomers

17. Acids, Bases & Salts
Acid – a substance that releases H+ (hydrogen ions); pH<7
Base (alkaline) – a substance that releases OH- (hydroxide ions) or decreases H+ ; pH>7
Salt – substance composed of positively charged ions (not H+ ) and negatively charged ions (not OH-); usually neutral
Buffers – substances that react with strong acid or base to keep pH constant by absorbing or releasing H+ or OH- as needed; helps to maintain homeostasis

18. pH Scale

19. Ketoacidosis/Alkalosis
Ketoacidosis: A feature of uncontrolled diabetes mellitus characterized by a combination of ketosis and acidosis. Ketosis is the accumulation of substances called keytones and ketone bodies in the blood. Acidosis is increased acidity of the blood
Alkalosis: A state characterized by a decrease in the hydrogen ion concentration of arterial blood. The condition may be caused by an increase in the concentration of alkaline compounds, or by a decrease in the concentration of acidic compounds or carbon dioxide.

20. Organic Chemistry Molecules contain H-C & C-C bonds
Carbohydrates – carbon + water
glycogen – animals store energy in this carb.
Starch – plants store energy in this carb.

21. Phospholipids – major component of cell membranes
Lipids – fats, oils and waxes – non polar, therefore they do not dissolve appreciably in water
Phospholipids – major component of cell membranes
Triglycerides – energy storage
Cholesterol – steroid lipid – component of cell membrane; precursor to steroid hormones

22. Phospholipid Triglyceride

24. Enzyme – protein that acts as a catalyst
Proteins - most varied of all the organic molecules in function; enzymes, structural, hormones, immunological, membrane components – building blocks are amino acids
Enzyme – protein that acts as a catalyst
Co-enzyme – some enzymes don’t function unless a co-enzyme is present (vitamins may serve this function)

25. Nucleic Acids – DNA and RNA (genetic material)

27. ATP – a modified nucleotide
The role of ATP is to transfer energy from nutrient molecules to cellular processes