Consider the following: succinate dehydrogenase catalyzes the conversion of succinate to fumarate. the reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid. which of the following is correct?
a. succinate dehydrogenase is the enzyme, and fumarate is the substrate.
b. succinate dehydrogenase is the enzyme, and malonic acid is the substrate.
c. succinate is the substrate, and fumarate is the product.
d. fumarate is the product, and malonic acid is a noncompetitive inhibitor.
e. malonic acid is the product, and fumarate is a competitive inhibitor.

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.)