1. Which of the following does not contain functional ribosomes?

a. / a prokaryotic cell
b. / a plant mitochondrion
c. / a chloroplast
d. / an animal mitochondrion
e. / a nucleolus
  1. Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

a. / lipids
b. / starches
c. / proteins
d. / steroids
e. / glucose
  1. Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?

a. / ribosome
b. / lysosome
c. / smooth endoplasmic reticulum
d. / mitochondrion
e. / contractile vacuole
  1. Which structure is the site of the synthesis of proteins that may be exported from the cell?

a. / rough ER
b. / lysosomes
c. / plasmodesmata
d. / Golgi vesicles
e. / tight junctions

The equation above shows one of the reversible reactions that occur in blood. After exercise, an athlete’s blood pH has dropped below the normal level. How will normal blood pH be restored?

H++ HCO3__<-> H 2 O + CO2

(A)An increase in O2 concentration in the plasma will lead to an increase in H+ concentration.

(B)An increase in temperature will lead to an increase in H+ concentration.

(C)An increase in sweating will lead to a decrease in OH– and H+ concentration.

(D)An increase in breathing rate will lead toa decrease in blood CO2 and H+ concentration.

  1. Cystic fibrosis is a recessively inherited disorder that results from a mutation in the gene encoding CFTR chloride ion channels located on the surface of many epithelial cells. As shown in the figure, the mutation prevents the normal movement of chloride ions from the cytosol of the cell to the extracellular fluid. As a consequence of the mutation, the mucus layer that is normally present on the surface of the cells becomes exceptionally dehydrated and viscous.

An answer to which of the following questions would provide the most information about the association between the CFTR mutation and the viscous mucus?

  1. Is the mucus also secreted from the cells through the CFTR proteins?
  1. How does the disrupted chloride movement affect the movement of sodium ions and water by the cell?
  2. How does the mutation alter the structure of the CFTR proteins?
  3. What is the change in nucleotide sequence that results in the CFTR mutation?
  1. The diagram (above/previous page) illustrates feedback control as exerted by the hormone thyroxine. Following surgical removal of the thyroid gland, the level of TSH in the blood will increase. Which of the following best explains this increase?
  1. Residual blood thyroxine, from prior to thyroid gland removal, will bind to cells in the anterior pituitary, signaling more TSH secretion.
  1. Thyroxine will remain bound to thyroxine receptors on various body cells, and these body cells will secrete additional hormones that stimulate the anterior pituitary to secrete TSH.
  1. Thyroxine that was stored in the anterior pituitary prior to thyroid gland removal will signal more TSH secretion.
  1. A decrease in thyroxine levels means a loss of inhibition to the hypothalamus and anterior pituitary, leading to increased TSH secretion.
  1. Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

a. / catalysis
b. / metabolism
c. / anabolism
d. / dehydration
e. / catabolism
  1. Which of the following is a statement of the first law of thermodynamics?

a. / Energy cannot be created or destroyed.
b. / The entropy of the universe is decreasing.
c. / The entropy of the universe is constant.
d. / Kinetic energy is stored energy that results from the specific arrangement of matter.
e. / Energy cannot be transferred or transformed.
  1. Which of the following statements regarding enzymes is true?

a. / Enzymes decrease the free energy change of a reaction.
b. / Enzymes increase the rate of a reaction.
c. / Enzymes change the direction of chemical reactions.
d. / Enzymes are permanently altered by the reactions they catalyze.
e. / Enzymes prevent changes in substrate concentrations.
  1. The active site of an enzyme is the region that

a. / binds allosteric regulators of the enzyme.
b. / is involved in the catalytic reaction of the enzyme.
c. / binds the products of the catalytic reaction.
d. / is inhibited by the presence of a coenzyme or a cofactor.
e. / both A and B
The following questions are based on the reaction A + B C + D shown in the figure below

  1. Which of the following terms best describes the reaction?
a. / endergonic
b. / exergonic
c. / anabolic
d. / allosteric
e. / nonspontaneous
  1. Which of the following represents the G of the reaction?
a. / a
b. / b
c. / c
d. / d
e. / e
  1. Which of the following does not contain functional ribosomes?
a. / a prokaryotic cell
b. / a plant mitochondrion
c. / a chloroplast
d. / an animal mitochondrion
e. / a nucleolus
  1. Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
a. / lipids
b. / starches
c. / proteins
d. / steroids
e. / glucose
  1. Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
a. / ribosome
b. / lysosome
c. / smooth endoplasmic reticulum
d. / mitochondrion
e. / contractile vacuole
  1. Which structure is the site of the synthesis of proteins that may be exported from the cell?
a. / rough ER
b. / lysosomes
c. / plasmodesmata
d. / Golgi vesicles
e. / tight junctions