Review Questions

Cell going through anaphase Nerve cell Cell Schematic: Eukaryote ATP

Test 1

    1. "Omnis cellula e cellula" was the latin term for the third tenet of cell biology. What does it mean?
    2. What are the first two tenets?
    3. What two pieces of modern lab equipment revolutionized the understanding of cellular architecture?

  2. In the proverbial "primordial world" RNA served two vital functions.
    1. What were they?
    2. What molecules replaced theose functions?
    3. Very briefly, why were those functions replaced by other molecules?

  3. Anaerobes can exist as eukaryotes or as prokaryotes, but they are never multicellular. Why are words like multicellularity, diversity, and abundance reserved for aerobes?

  4. What is the net charge of the following hypothetical ploypeptide in solution at pH 0, pH 5, pH 7, and pH 9?

    NH3- Glu - His - Met - Gly - Ala - His - Ser - Thr - Tyr - His - Asp - Val - COOH

  5. If the pK of a protein is 5.0, what is the pH of a solution of the protein if it is 25% dissociated?

  6. A polypeptide contains the following amino acids: (2) Valine, (3) Glycine, (2) Histidine, (1) Aspartate, (2) Methionine, (1) Lysine, (1) Alanine, (1) Arginine, (2) Serine, (1) Cysteine, and (1) Tyrosine. What is its charge at pH9? What is its pI?

  7. If the amino acid cysteine was present is solution and was 75% dissociated, what would the pH of the solution be?

  8. If enzyme E catalyzed a reaction with substrate S, calculate Km and Vmax, assuming you experimentally obtained the following V and [S]:

    V(moles/sec) [S](micro moles)
    0.00 0.00
    0.20 0.33
    0.25 0.50
    0.33 1.00

  9. What type of inhibition is occurring when enzyme (E) in the presence of inhibitor (I) and gives the following V and [S] data? What are the values of Km (apparent) and Vmax (apparent)?

    V(moles/sec) [S](micro moles)
    0.250 1.000
    0.200 0.500
    0.125 0.200

  10. At What stage of protein synthesis and assembly is energy input required?

  11. Name two types of secondary protein structure and state the chemical bond type that stabilizes that structure?

  12. Name the types of non-covalent bonds that play roles in three dimentional protein structure, and give examples of amino acid "R" groups that would be likely to participate in each type. Do the same for the most common covalent bond contributing to three-dimentional protein structure.

  13. In a short paragraph, address the following: How do each of the orders of protein structure depend on the previous order(s), and what does this imply about the primary structure? What general process governs the formation of protein structure beyond the primary structure?

  14. Name the various types of chemical bonds involved in protein synthesis and assembly. State whether each is covalent or non-covalent, and for each, state the level of structure at which its role is particularly important or relevant.

  15. What is the activated monomer form for the following biological polymers?
    1. DNA
    2. Glycogen
    3. Protein


  16. What did the Anfinsen & White experiment show?

  17. Name three characteristics typical of enzyme active sites.

  18. Virtually all enzymes have optimum rates of reaction over a narrow range of pH, Why is the pH optimum range always narrow?

  19. Make an educated guess about the molecular structure of an enzyme active site with a pH optimum of 4.5. Give your reasoning.