You treat some cells with a proteolytic enzyme that is too large to penetrate the cell membrane (Set 1). Another group of cells is made permeable to the enzyme before treatment with the enzyme (Set 2). A third set of cells was NOT treated with the enzyme at all (controls). Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. Protein W migrates to the same distance on a gel of proteins from Set 1 and Set 2; Protein W migrates a shorter distance on gels of proteins extracted from the control group than on gels of proteins extracted from Set 1 and Set 2 treated cells. Protein X migrates to the same distance on a gel of proteins from control cells and the gels of the proteins from Set 1 and Set 2. Protein Y migrates a longer distance when
extracted from Set 1 cells than does protein Y in the controls; Protein Y moves an even larger distance in the gel of the extracts from Set 2. Protein Z migrates the same distance on gels of proteins from the controls and the proteins extracted from Set 1, but it migrates a longer distance in extracts from Set 2 cells. Which protein is exposed only on the exterior of the cell?
a) protein X
b) protein Z
c) protein Y
d) protein W
Ans: d) protein W
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Which of the following correctly lists the terms in hierarchical order from the most inclusive
to the least inclusive?
a. kingdom, domain, class, phylum b. species, kingdom, order, family c. class, order, family, genus d. order, phylum, family, species
Which of the following is not an advantage of uric acid excretion in terrestrial animals?
a. Uric acid can be excreted as a paste, thereby conserving water. b. Uric acid is not toxic and can be safely stored. c. Uric acid can be stored in the eggs of animals without harm to the embryos. d. Uric acid is soluble in water and can be easily excreted. e. Uric acid can be excreted along with feces in some animals.
What plant secondary metabolite was isolated from the Cinchona tree to fight malaria?
A. taxol B. penicillin C. digitalis D. acacia E. quinine
Some lac operon mutations allow for beta galactosidase to be expressed constitutively even in the absence of lactose. Which of the following lac genotypes would allow for this constitutive expression?
A) I+ P- O+ Z+ Y+ A+ B) Is P+ O+ Z+ Y+ A+ C) I+ P+ O+ Z+ Y+ A+ D) I+ P+ Oc Z+ Y+ A+ E) I+ P+ O+ Z- Y+ A+