Bio 151: Exam 2
1. Give two specific reasons why a virus is not considered to be a cell. [4 pts]
Viruses are not considered cells because:
- they cannot replicate or perform metabolic reactions on their own
- they do not contain ribosomes or cytoplasm
2. Which of the following is present in a prokaryotic cell? [2 pts]
3. What is the main structural difference between enveloped and non-enveloped viruses? [2 pts]
a. Enveloped viruses have their genetic material enclosed by a layer made only of protein.
b. Non-enveloped viruses have only a phospholipid membrane, while enveloped viruses have two membranes, the other one being a protein capsid.
c. Enveloped viruses have a phospholipid membrane outside their capsid, whereas non-enveloped viruses do not have a phospholipid membrane.
d. Both types of viruses have a capsid and phospholipid membrane; but in the non-enveloped virus the genetic material is between these two membranes, while in the enveloped virus the genetic material is inside both membranes.
4. Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the: [2 pts]
b. golgi apparatus
d. endoplasmic reticulum
5. Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to: [2 pts]
a. form pseudopodia
b. perform vesicle transport
c. maintain the shape of the nucleus
d. transcribe motor protein mRNA
e. all of these answers are correct
6. Describe the key difference between pinocytosis and receptor-mediated endocytosis. [2 pts]
Pinocytosis is a non-specific endocytic process that brings small solutes into the cell. In receptor-mediated endocytosis, a specific molecule is endocytosed upon binding to a transmembrane receptor.
November 7, 2014
7. Matching. Some proteins are named or described below. For each one, choose the letter(s) of the cell structure(s) where that protein would be found at some point. (The protein does not have to function in each structure you choose, if it is found there at some point.) Use as many letters per blank as needed; you may use each letter once, more than once or not at all. [10 pts]
a. cytosol b, c, h, j
b. Golgi apparatus
c. vesicle a hemoglobin, the major cytoplasmic protein in red blood cells
e. mitochondrion b, c, d, j trypsin, an enzyme used to digest worn-out cell components
g. nucleus b, c, j insulin, a protein hormone released into the blood
h. cell membrane
j. rough ER
k. smooth ER a, j
L16, a protein which is part of the large ribosomal subunit
8. Draw a diagram of an HIV viral particle. On your drawing, label each of the following: capsid, envelope, gp120 proteins, viral RNA. Also show and name any enzymes that are present in the virus. [5 pts]
9. 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: [2 pts]
10. The fact that mitochondria have their own DNA and their own ribosomes supports the: [2 pts]
a. induced fit model.
b. endosymbiosis theory.
c. lock-and-key model.
d. fluid mosaic model.
e. None of the above.
November 7, 2014
11. The spliceosome contains which of the following: [2 pts]
a. RNA Polymerase III
d. Transcription factors
12. Alternative RNA splicing: [2 pts]
a. is a mechanism for increasing the rate of translation
b. can allow the production of proteins of different