_________ are small molecules or proteins that are produced in one tissue, released into the bloodstream, and carried to other tissues, where they act through specific receptors to bring about changes in cellular activities.
A: Sugars
B: Hormones
C: Lipids
D: Nucleotides
A: Sugars
B: Hormones
C: Lipids
D: Nucleotides
举一反三
- A globular particle, containing lipids and proteins, that transports lipids between tissues via the bloodstream is a/an _______ _.
- In gel electrophoresis, （）proteins move rapidly through the gel. A: Large molecules B: Small molecules C: Both move together D: The above options are not selected
- Which of the following narrative about hormones is wrong? ____ A: Hormones are highly bioactive substances secreted by various glands in the body B: Most hormones are transported to target cells long distance away through blood circulation C: Some hormones can diffuse to adjacent cells through tissue fluid D: Hormones secreted by nerve cells can reach the adenohypophysis through the pituitary portal vein
- Which one is NOT the characteristic of hormones? ( ) A: Hormone is a chemical substance secreted from endocrine glands or<br/>endocrine cells. B: Hormones are released directly into arteries and circulate in the<br/>blood throughout the body. C: Each hormone exerts specific effects on certain organs or tissues. D: Some hormones have many target organs. E: Some hormones have only one or a few target(s).
- One of the major tasks of hormones is to coordinate the activities of organ systems.