Multiple Choice: Circle the best answer.

1. A cell is producing a protein for export. Place the following
     events  in the correct sequence.
     1. Processing of protein in the Golgi complex.
     2. Packaging of protein into transport vesicles.
     3. Protein leaves the Golgi complex by budding off the Golgi
          membrane.
     4. Transport vesicles bud off from endoplasmic reticulum.
     5. Transport vesicles fuse with the Golgi complex.
     6. Translation of message with aid of ribosomes in the
          endoplasmic reticulum.
     7. Vesicle fuses with plasma membrane.
     8. Vesicle migrates to plasma membrane.

     a. 6-2-4-5-1-3-8-7
     b. 5-7-4-3-8-7-2-1
     c. 4-5-6-7-8-3-2-1
     d. 2-6-4-5-6-3-7-8
     e. 3-5-7-1-2-4-6-8

2. Which cell structure is responsible for packaging materials for
     export?
     a. plasma membrane
     b. chloroplasts
     c. lysosomes
     d. vacuoles
     e. Golgi complex

3. Which one of the following is correctly matched?
     a. chloroplast - storage of enzymes
     b. lysosome - powerhouse of cell
     c. nucleolus - site of ribosomal synthesis
     d. glyoxysome - structural support of cell
     e. Golgi complex - production of energy

4. In photosynthesis ATP is produced in the:
    a. cristae membrane.
    b. thylakoid membrane.
    c. nucleus.
    d. nucleolus.
    e. ribosomes.

5. Which of the following organelles is found in both plant and
     animal cells?
     a. chloroplast
     b. cell wall made of cellulose
     c. tonoplast
     d. mitochondrion
     e. centriole

6. In a lipid bilayer, _____ fatty acid tails face each other within the
     bilayer and form a region that excludes water.
     a. hypertonic
     b. hyperosmotic
     c. hypotonic
     d. hydrophilic
     e. hydrophobic

7. Peripheral proteins can be associated with either the inner or
    outer surface of the plasma membrane. They are:
     a. covalently linked by disulfide bonds.
     b. associated with the fatty acids by hydrophobic interactions.
     c. imbedded in only one side of the membrane and thus do not
         extend through to the other side.
     d. always glycoproteins.
     e. usually bound to integral proteins by weak linkages.

8. Which of the following molecules would diffuse across a plasma
     membrane most easily?  Assume that there is no active transport
     or  facilitated diffusion.
     a. amino acid
     b. glycerol
     c. starch
     d. nucleotide
     e. protein

9. The passive movement of materials along its own concentration
     gradient is termed:
     a. active transport.
     b. dialysis.
     c. diffusion.
     d. exocytosis
     e. osmosis.

10. Penicillin is toxic to certain dividing bacterial cells because it
       prevents cell wall formation, causing the cells to burst. This
       indicates that the bacteria live in a (an):
      a. hypotonic medium.
      b. hypertonic medium.
      c. isotonic medium.
      d. medium with higher osmotic pressure than the cell.
      e. Both b and d are correct.

11. A cell takes droplets of liquid containing dissolved materials by:
      a. carrier mediated facilitated diffusion.
      b. exocytosis.
      c. phagocytosis.
      d. pinocytosis.
      e. the sodium potassium pump.

12. A bacterium is living in a pond where the concentration of a
      sodium ions is 0.005 mM (millimolar). This ion is found in the
      bacterial cytoplasm at a concentration 0.10 mM.   Therefore
      the sodium ion is probably entering by:
      a. active transport.
      b. endocytosis.
      c. diffusion.
      d. facilitated diffusion.
      e. osmosis.

13. A white blood cell engulfs and takes in a bacterial cell by
      a. carrier mediated facilitated diffusion.
      b. exocytosis.
      c. phagocytosis.
      d. pinocytosis.
      e. the sodium potassium pump.

14. The concentration of potassium in a red blood cell is much
       higher  than it is in the surrounding blood plasma, yet potassium
      continues to move into the cell. The process by which
      potassium  moves  into the cell is called:
      a. osmosis
      b. exocytosis
      c. phagocytosis
      d. active transport
      e. pinocytosis

15. Which of the following statements is not true about enzymes in
       general?
      a. they increase the rate of a reaction
      b. they function by decreasing the activation
          energy required for the reaction
      c. to work, they must obtain energy provided by active
          transport
      d. they are catalysts
      e. they are affected by pH and temperature

16. Pinocytosis refers to the uptake of _________  molecules by a
      cell.
      a. membrane-bound
      b. dissolved or liquid
      c. solid food
      d. large
      e. horsetail shaped

17. A cellular organelle that is not enclosed by a membrane:
      a. Golgi complex
      b. nucleus
      c. ribosome
      d. chloroplast
      e. mitochondria

18. The interaction between an enzyme and its substrate:
      a. involves the whole enzyme
      b. is non-reversible
      c. is called a tight junction
      d. is nonspecific
      e. is specific

19. Where does protein synthesis occur?
      a. in the nucleus
      b. in vacuoles
      c. on chromosomes
      d. on ribosomes
      e. it depends on whether the organism is
          prokaryotic or eukaryotic

20. Prokaryotic cells have all of the following except
      a. cell membrane
      b. cell wall
      c. cytoplasm
      d. nucleus

21. Which cell structure is characteristic of plants but not animals?
      a. cell membrane
      b. nucleus
      c. ribosomes
      d. mitochondria
      e. vacuoles

Short Answer. Answer each question in the space provided.

1. The type of cell transport that is carrier
     mediated yet passive is called? ___________

2. What is the name of the membranous structure
     containing digestive enzymes and thought to
     be involved in the break down of cells
     following death? ____________

3. These microbodies contain enzymes used for
     converting fats to sugars in plants. _________

4. The process of ribosome synthesis in the
     nucleolus of the nucleus is termed? ________

Essay. Answer the questions in the space provided. The value of
each question is indicated in parenthesis.

1. Compare the basic structure of eukaryotic and prokaryotic cells.
     What do they have in common? How are they different?  (8 pts)

2. Explain how enzymes lower the activation energy needed to
    initiate a chemical reaction. (6 pts)

3. Explain what is meant by enzyme cofactors. (6 pts)

4.  List and describe the 3 basic types of  intercellular contacts
     found in animal cells. (6 pts) 

5. Why is it highly improbable that you will ever encounter a
     predatory two-ton living cell on the sidewalk? (8 pts)