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 components of total parenteral nutrition, Define Components of Total...

Define Components of Total parenteral nutrition? Glucose: Initiated at the rate of 6 mg/kg/min and increased upto 12-1.4 mg/kg/min, but care to be taken to prevent hyperglyce

Plant physiology, why does the removal of extremity of coleoptile prohibit ...

why does the removal of extremity of coleoptile prohibit plant growth?

Self help group - psychoactive substance use disorders, Self Help Group: ...

Self Help Group: The first and perhaps the most influential of substance abuse rehabilitation is Self Help Group. The self help programme was founded in 1935 by two men, Dr. B

Mycotoxicosis, M yc ot o xi c osi s There are several types of m...

M yc ot o xi c osi s There are several types of mycotoxins (toxins produced by the fungi) e.g. aflatoxin, ochratoxin etc. Many species of fungi produce them but Aspergi

Non-modifiable risk factors for coronaru heart diseases, Q. Non-Modifiable ...

Q. Non-Modifiable Risk Factors for coronaru heart diseases? Non-Modifiable Risk Factors 1. Age 2. Sex 3. Heredity 4. Endomorphic Body Build Family history: Pe

What is the radiographic evaluation, Radiographic Evaluation An intraor...

Radiographic Evaluation An intraoral periapical radiograph with a paralleling technique should be made and observed to ensure absence of pathology in the peri-implant region an

What are the destinations of those oxygen atoms, Q. Photosynthesis is the m...

Q. Photosynthesis is the most significant producer of molecular oxygen (O2) on our planet. From which molecule do oxygen atoms liberated by photosynthesis come and from which other

Homeostasis, HOMEOS T ASI S - Homeo = same,   Stasis = state Li...

HOMEOS T ASI S - Homeo = same,   Stasis = state Living beings maintain their internal environment by self regulating system, it is called homeostasis. Term coined by

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