1. A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate
the organelles. Organelles in one of the heavier fractions could produce ATP in the light,
whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter
fractions are most likely to contain, respectively, ________. - Answers a. chloroplasts and
mitochondria
1. What is the most likely pathway taken by a newly synthesized protein that will be secreted by
a cell? - Answers a. ER → Golgi → vesicles that fuse with plasma membrane
1. Asbestos is a material that was once used extensively in construction. One risk from working
in a building that contains asbestos is the development of asbestosis caused by the inhalation
of asbestos fibers. Cells will phagocytize asbestos but are not able to degrade it. As a result,
asbestos fibers accumulate in ________. - Answers a. lysosomes
1. Which of the following statements describes a fundamental difference between plant cells
and animal cells? - Answers a. Animal cells do not have chloroplasts.
1. A certain eukaryotic cell type specializes in synthesizing lipids. Which organelle would be
found in greater abundance in this cell type than in other cell types that do not synthesize lipids?
- Answers a. Smooth endoplasmic reticulum
1. Tay-Sachs disease is a human genetic abnormality that results in cells becoming packed with
very large undigested lipids. Which cellular organelle is malfunctioning in this condition? -
Answers a. Lysosomes
1. Which of the following organelles have a double membrane? - Answers a. Nucleus,
mitochondria, and chloroplasts
1. Which of the following statements best describes the fundamental difference between
prokaryotic and eukaryotic cells? - Answers a. Eukaryotic cells have a nucleus, whereas
prokaryotic cells do not have a nucleus.
1. You have discovered an enzyme that can catalyze two different chemical reactions. Which of
the following is most likely to be correct? - Answers a. Either the enzyme has two distinct active
sites or the reactants involved in the two reactions are very similar in size and shape.
1. The lock-and-key analogy for enzymes applies to the specificity of enzymes ________. -
Answers a. binding to their substrate
1. Which of the following statements is TRUE about enzyme-catalyzed reactions? - Answers a.
The reaction is faster than the same reaction in the absence of the enzyme.
1. In what important way does competitive inhibition differ from allosteric inhibition? - Answers
a. During competitive inhibition, a regulatory molecule binds to the active site, whereas during