Related topics: breast cancer · women · plants · estrogen · protein

A better pregnancy test for whales

It's not easy to do pregnancy tests on whales. You can't just ask a wild ocean animal that's the size of a school bus to pee on a little stick. For decades, the only way scientists could count pregnant females was by sight ...

Structure of human thyroglobulin identified

A team of researchers from the U.K., Slovenia and Germany has determined the structure of human thyroglobulin using cryo-electron microscopy. In their paper published in the journal Nature, the group describes their study ...

Solving the riddle of strigolactone biosynthesis in plants

Strigolactones (SLs) are a class of chemical compounds found in plants that have roles as plant hormones and rhizosphere signaling molecules. They regulate plant architecture and promote germination of root parasitic weeds ...

New insights into regulation of root initiation

When young, dark-grown seedlings of thale cress are given light, they start to form roots from the stem-like part of the plant called the hypocotyl. Abdellah Lakehal used this system to study how the initiation of these adventitious ...

Potentially harmful air contamination near New Bedford Harbor

A new Boston University School of Public Health (BUSPH) study indicates that the contaminated water of New Bedford Harbor may pose an airborne health hazard for residents living nearby in Acushnet, Dartmouth, Fairhaven, and ...

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Hormone

Hormones (from Greek ὁρμή - "impetus") are chemicals released by cells that affect cells in other parts of the body. Only a small amount of hormone is required to alter cell metabolism. It is essentially a chemical messenger that transports a signal from one cell to another. All multicellular organisms produce hormones; plant hormones are also called phytohormones. Hormones in animals are often transported in the blood. Cells respond to a hormone when they express a specific receptor for that hormone. The hormone binds to the receptor protein, resulting in the activation of a signal transduction mechanism that ultimately leads to cell type-specific responses.

Endocrine hormone molecules are secreted (released) directly into the bloodstream, while exocrine hormones (or ectohormones) are secreted directly into a duct, and from the duct they either flow into the bloodstream or they flow from cell to cell by diffusion in a process known as paracrine signalling.

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