The DNA in a cell's nucleus encodes proteins that are eventually targeted to every membrane and compartment in the cell, as well
as proteins that are targeted for secretion from the cell. For example, consider these two proteins: Phosphofructokinase (PFK) is an enzyme that functions in the cytoplasm during glycolysis.
Insulin, a protein that regulates blood sugar levels, is secreted from specialized pancreatic cells.
Assume that you can track the cellular locations of these two proteins from the time that translation is complete until the proteins reach their final destinations.
For each protein, identify its targeting pathway: the sequence of cellular locations in which the protein is found from when translation is complete until it reaches its final (functional) destination.
(Note that if an organelle is listed in a pathway, the location implied is inside the organelle, not in the membrane that surrounds the organelle.)
Options:
a. Cytoplasm only, ER --> cytoplasm,
b. ER --> Golgi --> outside cell,
c. cytoplasm --> ER --> outside cell,
d. Golgi --> ER --> outside cell,
e. cytoplasm --> Golgi --> outside cell,
f. nucleus --> cytoplasm,
g. ER --> Golgi --> cytoplasm
As described in the question, the enzyme phosphofructokinase (PFK) functions is a cells cytoplasm. Enzymes are proteins and proteins are made in the ribosomes of a cell. As ribosomes are present in the cytoplasm, hence PFK once made in the ribosomes will be released into the cytoplasm.
As for insulin, it will be made in the ribosomes. from there, it will move to the Endoplasmic Reticulum for packaging. Then to the Golgi complex for modifications and further packaging. Only after these stages, it will be ready to move out from where it is produces to areas where it has to be used.
The primary ethical guidelines that apply to this experiment are those of human experimentation.
The use of humans as subjects of experimentation would seem to demean their human dignity. The issue of abuse of the human subjects and also the prospects of the clinical trial going wrong (such as causing an adverse effect on the subjects) also raise ethical challenges even when the subjects are volunteers. In case of a clinical error, what is the right compensation?
The correct answer is <u /><em>a</em><em>daption</em>. The particular environment in which a particular environment is exposed to gives it the characteristic or the ability to adapt. This is how a particular ecosystem works. It is the relationship of organisms within their environment that evolves through time in order for it to survive and propagate into more adapted kinds of species.
