Final Exam

Tuesday, June 13, 9:30 a.m. LPSC 125

Key for the Final Exam

High score: 176
Average: 136

Samples from last year:

Link to the Exam Key (2016)

Scores and final grades will be posted on Canvas.

The final exam will be comprehensive.  You should confirm your mastery of material from the first two midterms.

In addition, we have covered the following material from Chapter 27-28:

Chapter 27:

• Be able to identify a reaction of an organic compound as one of the following:
  • Addition
  • Elimination
  • Substitution
  • Oxidation
  • Reduction
  • Rearrangement
• Be able to identify reagents based on their mode of action:
  • Nucleophiles (Lewis bases)
  • Electrophiles (Lewis acids)
  • Free radicals (species with unpaired electrons)
  • Oxidizers
  • Reductants
• You are not responsible for memorizing the many different reaction mechanisms.  However, you should understand the use of mechanistic arrows to illustrate the flow of electrons in individual steps of a multistep mechanism.
• You should understand the order of reactivity of different kinds of electrons:  lone pairs are most reactive; pi-bond electrons are the next in order; polar sigma bonds next; and nonpolar sigma bonds least reactive.
• You should understand how chemistry can be used to form polymeric molecules, and how sequences of reactions are used to make complex molecules.

Lipids

• Identification based on the presence of nonpolar groups
• Fatty acids and fats (triglycerides):  common sources, chemical origin in the chemistry of acetylCoA, distinction between saturated, monounsaturated, polyunsaturated.  Presence of cis alkenes in natural fats; origin of trans alkenes in processing hydrogenated fats and oils.
• Terpenes:  identification of isoprene units in terpenoid compounds.  Importance of terpenes as chemical signaling agents in biology (particularly steroids).

Carbohydrates

• Identificaltion based on molecular formula: C_n(H₂O)_n.
• Presence of hydroxyl group at every carbon; presence of one carbonyl group either at one end (aldose; reducing sugar) or in the middle (ketose, nonreducing sugar).
• Assignment of sugars as D or L based on the Fischer projection representation of the last stereocenter in the chain. Predominance of D sugars in nature.
• Representation of sugars as their cyclic form.
• Formation of di-, tri-, and polysaccharides. 

Amino acids and proteins

• Identification of amino acids generally You do not need to memorize the 22 naturally-occuring amino acids.
• Role of amino acid side chains:  hydrophobic, hydrophilic; acidic, basic.
• Primary structure of proteins and peptides:  amino acid sequence.  Recognition of peptides/proteins as polyamide polymers.
• Secondary structure:  a-helix and b-sheet.
• Tertiary structure:  protein folding; disulfide bonds.
• Quaternary structure:  multiple chains associating.
• Protein function:  binding/transport; enzyme catalysis of chemical reactions.