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

Define bioactive materials, Q. Define Bioactive materials? Bioactive ma...

Q. Define Bioactive materials? Bioactive materials: Certain glasses, ceramics, and glass-ceramics that contain oxides of silicon, sodium, calcium and phosphorus (SiO 2 , Na 2

What is active site, What is Active site Active site : The site on  ...

What is Active site Active site : The site on  the surface of an enzyme to which  substrate or substrates bind.

Ringworm, R i n g w o r m It is also known as dermatophytosis re...

R i n g w o r m It is also known as dermatophytosis resulting in alopecia, scab formation and ring like lesions in the affected body parts. Eti o logy: Zeop

Difference between spermatid and spermatocyte ii, Q. What is the difference...

Q. What is the difference between spermatid and spermatocyte II? The spermatids (n) are the products of the second division of meiosis (meiosis II) in the male gametogenesis an

Meiosis and Mitosis, #question.Consider a cell that has 10 homologous pairs...

#question.Consider a cell that has 10 homologous pairs of chromosomes and is just starting to go through meiosis. After meiosis is complete, there will be 40 cells that each contai

Zoology, Is viruses classified as living organism? If yes/no why

Is viruses classified as living organism? If yes/no why

What is a prion, Q. What is a prion? The prion is an infectious (transm...

Q. What is a prion? The prion is an infectious (transmissible) protein able to replicate by transforming other proteins into a copy of the prion. The mechanism of the copying i

Can be made from set of 20 naturally occurring amino acids, How many differ...

How many different molecules composed of (A) two (B) three, and (C) four amino acids, linked together by peptide bonds, can be made from the set of 20 naturally occurring amino aci

What is the molecular formula of glucose, Q. What is the molecular formula ...

Q. What is the molecular formula of glucose? How can its structural formula be explained? The molecular formula of glucose is C 6 H 12 O 6 . Structurally glucose is a hexago

Use of chemicals to control and destruct microorganisms, Q. Use of Chemical...

Q. Use of Chemicals to Control and Destruct Microorganisms? Ans. The use of chemicals, as a process of food preservation, has been used since long, ever since man found

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