AP Chemistry review

1. AP Chemistry review • Oxygen, hydrogen, nitrogen, and carbon make up 96% of the mass of all organisms • Protons (+), neutrons (0) and electrons (-) • Isotopes – same proton, different neutron number • Compound - two or more different atoms in fixed ratio • Chemical reactions • Ionic bonds vs. covalent bonds (non-polar covalent and polar covalent)

2. Covalent Bonding • Sharing of valence electrons to create molecules • Non-polar covalent – electrons are shared equally • Polar-covalent – not shared equally (water molecule) • Double and triple bonds

3. Ionic Bonding

4. Weak Bonding in living organisms • Bonding between molecules in the cell is very important • The contact can be brief. The molecules make contact, respond in some way then separate. • Ex. Chemical signaling in the brain

5. Water – polar covalent

6. Hydrogen Bonds Water and ammonia Water with Water

7. Properties of Water • Water is cohesive - because of hydrogen bonds – because of polarity • Water has surface tension due to cohesion • Water displays capillary action due to adhesion, which allows it to crawl up tubes. • Ice is less dense than water, therefore it floats • Water heats and cools slowly because of high specific heat. • Water is a biological solvent • Water has high heat of vaporization

8. Acids and bases • pH scale • Acids – H+ • Bases – OH- (alkaline) • Tenfold change – pH 3 is ten times more acidic than pH of 4

9. Organic Macromolecules • Polymers - Large molecules made by chains of small molecules • Carbohydrates, Lipids, Proteins, Nucleic Acids are all polymers • Organic – contain carbon • Inorganic – no carbon (except for CO2) • Watch this video

10. Carbohydrates • Mono, di, poly saccharides • Glucose and fructose are monosaccharides • Dehydration synthesis yields a disaccharide • Lose water • Maltose, sucrose are disaccharides • Hydrolysis breaks the bonds • Gain water

11. Dehydration synthesis

12. Starch, Glycogen, Cellulose • Starches - Carbohydrates stored by plants • Glycogen – Carbohydrates stored by animals in liver and muscle cells. Alpha glucose • Cellulose – forms the cell walls of plants and gives the plant structural support. Beta glucose • Chitin – exoskeletons of arthropods and cell walls of fungi. Beta glucose

13. Cellulose vs. starch

14. Proteins • Many uses in the cells and are integral in most every process in an organism’s body.

15. Peptide Bonding – Dehydration Synthesis • Lose water • Dipeptide then polypeptide • Many polypeptides folded and twisted becomes a functional protein • Primary to tertiary structure • As polypeptide advances in structure, binding sites are formed

16. Polypeptide Chains – Primary Structure

17. Secondary Structure

18. Tertiary Structure • Hydrophobic interactions between amino acids with nonpolar side chains cluster in the core of the pleated sheet or alpha helix. • Disulfide bonds between two cysteine amino acids also occur.

19. Quaternary Structure • Made up of two or more polypeptide chains. • Ex. Collagen and Hemoglobin

20. Protein structures

21. Types of proteins in the body • Structural – keratin, collagen, silk • Storage – albumin in eggs • Transport proteins on cell membranes • Defensive – antibodies • Enzymes – regulate all chemical rxns. in the body

22. Lipids – Dehydration synthesis • Lipids – Fats, oils, phospholipids, steriods • Nonpolar – they do not dissolve in water • Long term energy storage, insulation, and protection • Major component of the cell membrane • Glycerol molecule and 3 fatty acid chains – ester linkage • Unsaturated vs. saturated

23. Triglyceride synthesis

24. Phospholipid Structure • Amphipathic – hydrophilic head and hydrophobic tails

25. Cholesterol

26. Nucleic Acids • Polymers of nucleotides - polynucleotides • Nucleotide – sugar, phosphate group, and nitrogen base • 4 nitrogen bases – adenine, guanine, cytosine, thymine • DNA – double helix – deoxyribonucleic acid – deoxyribose sugar • RNA – single strand – ribonucleic acid – ribose sugar

27. Pyrimidines • Single ring • Cytosine, thymine and uracil

28. Purines • Adenine and Guanine • Double Ring

29. Nucleic Acid Structure

30. Flow of Information in cells