Macromolecules

3 types of macromolecules

Proteins

Nucleic Acids

Polysaccharides

Proteins are polymers of Amino Acids // Polypeptides:

Draw the structure // amino terminus // carboxy terminus

See fig 2-2 for structure of the 20 AA

See fig 2-3 and 2.4 for polypeptide details

Nucleic Acids // Polynucleotides

What is a nucleotide? (Draw the structure, include the charges)

What is a nucleoside?

Look at figs.: 2-5, 2-6, 2-7

Look at key concept, pg 23. Why does the author describe these polymers as being “extraordinarily versatile”?

Non-covalent Interactions

Random Coil – changes shape constantly as its being bombarded by solvent molecules

Hydrogen Bonds – (partial charges). Partial (+) on H is attracted to partial (-) on another molecule. See fig 2-8

Hydrophobic Interactions – molecules (in water) that are poorly soluble in water are attracted to each other and exclude water. How does this relate to the nucleotide bases? (fig 2-9; rigid base stacking)

Ionic bonds – charged groups are attracted or repulsed. These are the strongest of the non-covalent bonds. pH extremes / high salt concentrations often neutralize these interactions. Note that polynucleotides have heavy (-) charges on their phosphate groups.

Van der Waals – Attractive forces generated when atoms or molecules have complementary shapes and are very close to each other.

Figure 2-10 summarizes all of these interactions.

Methods:

Electrophoresis – fig 2-11, 2-13, 2-14

separation based on charge // pH dependent

separation based on size // coat the protein or other molecule with a charge

Gene Cloning – fig 2-12

Why would you do this?