21. Why are biological macromolecules considered organic?
22. Soil covers a vast proportion of earth’s land surface, and is composed of both organic and inorganic components. By what process might it acquire its organic content? Propose an answer, describing this process in as much detail as you can imagine.
23. Amino acids have the generic structure seen below, where R represents different carbon-based side chains.
Describe how the structure of amino acids allows them to be linked into long peptide chains to form proteins.
24. Describe the similarities and differences between glycogen and starch.
25. Why is it impossible for humans to digest food that contains cellulose?
26. Draw the ketose and aldose forms of a monosaccharide with the chemical formula C3H6O3. How is the structure of the monosaccharide changed from one form to the other in the human body?
27. Explain at least three functions that lipids serve in plants and/or animals.
28. Why have trans fats been banned from some restaurants? How are they created?
29. Why are fatty acids better than glycogen for storing large amounts of chemical energy?
30. Part of cortisol’s role in the body involves passing through the plasma membrane to initiate signaling inside a cell. Describe how the structures of cortisol and the plasma membrane allow this to occur.
31. Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.
32. Describe the differences in the four protein structures.
33. Aquaporins are proteins embedded in the plasma membrane that allow water molecules to move between the extracellular matrix and the intracellular space. Based on its function and location, describe the key features of the protein’s shape and the chemical characteristics of its amino acids.
34. The information coding strategy employed by DNA is analogous to that used by a written alphabet. DNA varies the order of 4 bases (which we symbolize ATGC) to record information. How many symbols would you say are used by the English alphabet to record information? How many are used in mathematics to code numerical information? How many are used to code information within computer circuits?
35. What are the four types of RNA and how do they function?