BILD 1 Dr. Nigel Crawford Winter 1997 Due: Jan. 16, 1997 PROBLEM SET #1 1. If a triglyceride is treated with base (NaOH), the ester bonds are broken regenerating the original components of the molecule. Draw this reaction, showing the structures of a triglyceride molecule and its breakdown products. Give names to each of the breakdown products. 2. A molecule of nucleic acid has the sequence CTTGTCCAGTCTGGACAA. Is this oligonucleotide RNA or DNA? This molecule can fold back on itself and form hydrogen bonds between the nitrogen bases producing a hairpin structure. Draw this structure. 3. Draw a glycosidic linkage between a glucose molecule and a threonine molecule given the threonine residue is part of a polypeptide chain. 4. Hydrogen bonds and hydrophobic interactions usually involve hydrogen atoms. How do these chemical interactions differ? 5. Phospholipids are important constituents of membranes. Draw a phospholipid, showing the hydrophobic regions and the hydrophilic regions. How would this molecule interact with another phospholipid molecule? 6. Is valine considered a hydrophobic or hydrophilic amino acid? Draw its structure, showing any hydrophobic and hydrophilic regions of the molecule. Consider valine as a free amino acid first then as part of a polypeptide chain. 7. Histones are positively charged proteins that bind tightly to DNA. Which amino acids would be found in histones that would confer the positive charge and what part of DNA would they bind? 8. 100 millimoles (0.1 moles) of ammonia are dissolved in 1 liter of water and completely ionize (form ammonium ion). What would be the concentration of OH- anions and what would be the pH? 9. List the four macromolecules found in all cells. Name the central linkages that connect the monomer units of these molecules and draw a picture of the linkage.