Steroid and thyroid hormones, Biology

Assignment Help:

Steroid and Thyroid Hormones

Cytoplasmic receptors for steroids are proteins with two subunits that bind to the steroid molecules. When both receptor sites are occupied by the steroid then the receptor-steroid complex migrates to the nucleus where one subunit ensures that the complex binds to the specific site on the chromatin. Then the receptor subunits separate and the other subunit interact directly with the adjacent region of DNA molecule resulting in the transcription of the DNA segment into mRNA.

Thyroid hormone acts in a similar manner except that the receptor is located in the nucleus. The major hormone secreted by thyroid is thyroxine (T4). It travels in blood attached to carrier proteins. Thyroid also secretes a small amount of triiodothyronine (T3). Carrier proteins have higher affinity for T4 and very little T4 is free in the plasma. Only the free T4 and T3 enter the cells. The rest of the bound T4 acts as a reservoir for slow release. The free T4 that enters the cell s also converted to T3 enzymatically. Therefore, T3 is the chemically more potent and active form of thyroid hormone.

552_Steroid and Thyroid Hormones.png

Figure:Steroid and Thyroid Hormones


Related Discussions:- Steroid and thyroid hormones

Animals in the community - nature of community, Animals in the Community - ...

Animals in the Community - Nature and Structure of Community The animals in the community are directly or indirectly dependent on the plants also time their activities in such

Determine the food-searching activity, The Svalbard ptarmigan (Lagopus mutu...

The Svalbard ptarmigan (Lagopus mutus hyperboreus) is a small herbivorous bird that lives permanently on the island chain of Svalbard. Svalbard is located in the Arctic Circle, app

Determine health hazards associated with high altitude, Determine Health Ha...

Determine Health Hazards Associated with High Altitude? Abrupt exposure to altitudes greater than 10,000 ft (3050 in) elevation is frequently associated with symptoins of altit

Diabetes mellitus in the world, Diabetes Mellitus in the World As per t...

Diabetes Mellitus in the World As per the International Diabetes Federation Directory, in 1994 the global burden of the disease was estimated at 110 million. These cases will i

Fats requirement in pectic ulcer, Q. Fats requirement in pectic ulcer? ...

Q. Fats requirement in pectic ulcer? Fats: These delay the gastric emptying. The products of fat digestion in the small intestine stimulate entrogastrone, which inhibits gastri

Show the use of incineration for sterilization, Q. Show the Use of Incinera...

Q. Show the Use of Incineration for sterilization? This is an excellent method for rapidly destroying materials such as soiled dressings, animal carcasses, bedding and patholog

Digestion, Digestion The nutritional requirements and the various way...

Digestion The nutritional requirements and the various ways used by heterotrophic organisms to obtain nutrition. Whether food is used to give energy or to build the body, the

Dealcoholism, DEALCOHOLISM - Treatment of alcoholism or withdrawal s...

DEALCOHOLISM - Treatment of alcoholism or withdrawal symptoms of alcohol is known as dealcoholism. Recovery from alcohol dependence is greatly aided by sociobehavioural c

Mycroboilogy mycoplasma, How we write assimgment about mycobiology of mycop...

How we write assimgment about mycobiology of mycoplasma in detail

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd