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

Birth of genetics, Birth of Genetics Modern genetics originated with Gr...

Birth of Genetics Modern genetics originated with Gregor Mendel's work. It is based on this paper entitled "Experiments in Plant Hybridisation " published in 1866 inqthe Procee

What is its function of cardia, Q. What is the route of the ingested food f...

Q. What is the route of the ingested food from swallowing until the duodenum? Until reaching the duodenum the food enters the mouth, passes the pharynx, passes the stomach and

Define procedure for gram staining of bacterial cultures, Define Procedure ...

Define Procedure for Gram Staining of Bacterial Cultures? Now carry out the exercise following the steps enumerated herewith: 1. Label the nutrient agar plates with the name

Light and dark reactions, Evidence for Existence of Light and Dark Reaction...

Evidence for Existence of Light and Dark Reactions The process of photosynthesis was known in its bare outline already at the beginning of this century. But the phenomenon wa

Explain the taxonomy of lamarck, Explain the taxonomy of Lamarck? Lamar...

Explain the taxonomy of Lamarck? Lamarck's taxonomy was mainly static in nature and his classification does not show its true value to the development of modern taxonomy. His m

Which is an isotope of pgisphorous, The most abundant from of phosphorous h...

The most abundant from of phosphorous has 15 protos, 16 neutrons and 15 electrons. Which of the following is an isotope of pgisphorous? (make all correct choices) A. an atom wit

Define affluence availability of food as factor for obesity, Define Affluen...

Define Affluence and abundant availability of food as factor for obesity? With increasing affluence, increase in purchasing power and abundance of food, people tend to eat more

Define the term- ultrafiltration, Define the term- Ultrafiltration Ultr...

Define the term- Ultrafiltration Ultrafiltration occurs when the flow of a substance across a cell membrane is increased by a hydrostatic pressure. This process was initially b

How to placing the implants in immature grafted, Placing the Implants in Im...

Placing the Implants in Immature Grafted Sites One of the most common causes of prosthetically related implant failure is believed to be the too rapid loading of the implant su

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