Major Concepts to Review for AP Exam

Macromolecules of Life

 

Dehydration Linkage - Monomers -----> Polymer + H2O

Hydrolysis - Polymers + H2O ----> Monomers (a hydrolytic change)

 

Carbohydrates

Monomers are sugars which undergo dehydration reactions to form -polymers (glycosidic linkage)

Polymers include:

plant starchs (amylase or amylopectin). Starch turns black/blue with iodine)

animal starch - glycogen

cellulose (structural polymer in plants only)

chitin (structural polymer in animal exoskeletons and cell walls of fungi)

 

The enzyme that can break the 1-4 beta links in cellulose = cellulase

 

Lipids

 

Everything that is hydrophobic is considered a lipid

3 Fatty Acids + Glycerol = Fats or triglycerides

Saturated lipids have no double bonds (animal fats)

Unsaturated fats have one or more double bonds (plant oils)

 

Cholestrol ----> Steriods (hormone) 4 linked rings + side chains

Enzyme which breaks down lipids = lipase

 

Proteins

 

Monomers for polypeptides include 20 different Amino Acids

Polymers - dehydration reactions produce peptide bonds and an infinite variety of polypeptides or proteins are possible.

4 Levels of protein structure are:

 

1st - Linear arrangment of amino acids (peptide bond)

2nd - Double Helix or B-pleated sheets (Hydrogen Bonds)

3rd - Globular (3d) shape (hydrogen, ionic, hydrophobic, and covalent bonds)

4th - 2 or more polypeptides combine usually forming an allosteric site which is involved in enzyme regulation. All four types of bonding is possible

 

Various proteases are involved in protein digestion.

 

 

Nucleic Acids

 

Monomers are nucleotides. 5 nucleotides are Adenine, Thymine, Guanine, Cytosine, and Uricil.

There are two nucleic acids; DNA and RNA

 

DNA has the following properties:

Contains A,T, C and G and the sugar deoxyribose

Much larger than RNA

Usually a double helix

Very stable and easily repaired

Functions primarily in data storage and transmission by replication.

 

RNA has the following properties:

Contains A,U, C and G and the sugar ribose

Much smaller than DNA

Usually a single stranded molecule

Easily mutated

Functions primarily in data conversion by translation (protein synthesis), and may act as a catalyst (ribozyme)

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