Question

Hormones . . . (choose all correct)

a. are transported by membrane proteins into target cells
b. can only act on cells that have receptors must be in mM concentration to exert effect
c. are sometimes secreted by isolated
d. cells rather than by discrete endocrine glands

Answer 1

Answer: Option A.

Step-by-step explanation:

Hormones are chemical substances secreted by endocrine glands into the blood stream which serve as Messengers, controllers and coordinators of body activities. When hormones are secreted into the blood, the blood carries them to organs, tissues and body part where they will perform their function. They coordinate complex processes like growth and are transported by membrane proteins into target cells.

Answer 2

A

Step-by-step explanation:

Endocrine hormone are secreted into the blood and carried by blood and tissue fluids to the cells they act upon, while exocrine hormones are secreted into a duct, and then into the bloodstream. Exocrine hormones are transferred from cell to cell by diffusion (paracrine signaling).

Hormones are typically secreted into systemic circulation. However, some are secreted into portal systems that allow for direct hormone targeting.

Hormones can exist freely in systemic circulation, but the majority are bound with transport proteins.

Transport proteins hold hormones inactive in systemic circulation and create a reservoir within the circulation that facilitates an even distribution of hormones throughout the tissue or organ.

transport protein: A protein that binds with a hormone in systemic circulation that facilitates its efficient transport.