Aprotein channel, like the peripheral and integral proteins in the diagram, is a transport protein that. a. always moves substances against a concentration gradient. b. always moves substances with a concentration gradient. c. serves as a tunnel for specific substances. d. always requires energy from the cell. i'm thinking a or d but i'm not sure.

Surrounded by microtubules, located near the nucleus. (don't try to google it) (give answer only if u know)

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Which direction does the energy flow in this energy pyramid ?