What would happen in each of the following cases? Assume in each case that the protein involved is a soluble protein, not a membrane protein
A. You add a signal sequence (for the ER) to the N-terminal end of a normally cytosolic protein.
B. You change the hydrophobic amino acids in an ER signal sequence into charged amino acids.
C. You change the hydrophobic amino acids in an ER signal sequence into other hydrophobic amino acids.
D. You move the N-terminal ER signal sequence to the C-terminal end of the protein.
A. The protein will now be transported into the ER lumen.
B. The altered signal sequence will not be recognized and the protein will remain in the cytosol.
C. The protein will still be delivered into the ER. It is the distribution of hydrophobic amino acids that is important, not the actual sequence.
D. The protein will not enter the ER. Because the C-terminus of the protein is the last part to be made, the ribosomes synthesizing this protein will not be recognized by the signal-recognition particle (SRP) and hence not carried to the ER.
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Indicate whether the statement is true or false.
Malarial parasites' favorite food source is
a. chitin. b. collagen. c. myosin. d. hemoglobin. e. fibrinogen.
The photosynthetic symbiont of a lichen is often a(n)
a) ascomycete. b) green alga. c) small vascular plant. d) moss. e) brown alga.
Please select the answers below that correspond to structural features of HIV and their host cells necessary for HIV infection to occur.
> The HIV envelope contains glycoproteins that mediate viral absorption and fusion to the host cell. > The helical HIV capsid opens to allow access of its single-stranded DNA genome to the host cell genome. > Infectable host cell membranes must present surface receptors including a CD4 marker, as well as a co-receptor. > Infectable host cells must actively phagocytize the HIV particle through the host cell membrane.