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

What is bile salts, What is Bile salts Bile salts have a considerable...

What is Bile salts Bile salts have a considerable ability to lower surface tension. By  this property, they prevent  the coming together of the small fat droplets in  the  in

VIRUSES, WHAT IS THE TYPICAL REPRODUCTION CYCLE OF A DNA VIRUS

WHAT IS THE TYPICAL REPRODUCTION CYCLE OF A DNA VIRUS

Define briefly about the conjugated proteins, Define briefly about the Conj...

Define briefly about the Conjugated Proteins? Conjugated proteins are made up of simple proteins combined with a non- proteinous substance. The non-proteinous substance is know

Leptospirosis, L e p t o s p i r o s i s It is zoonotic dis...

L e p t o s p i r o s i s It is zoonotic disease characterized by interstitial nephritis, haemolytic anaemia and abortions. E t iology : The disease i

Explain phylogenetically proximal species, Q. Do the phylogenetically proxi...

Q. Do the phylogenetically proximal species have cells with proximal chromosome counts? The number of chromosomes typical of each species is proximal for phylogenetically proxi

Explain nutrition or diet counseling, Explain Nutrition or diet counseling ...

Explain Nutrition or diet counseling Nutrition or diet counseling  is a  primary educational activity  of  the dietitian.  It incorporates the idea of working with a patient, e

Polyarthritis, It is the most common (occurring in 75 per cent cases of ARF...

It is the most common (occurring in 75 per cent cases of ARF) manifestation of ARF. It involves large joints, it is typically fleeting in character shifting from one large joint t

Pre and post-operative nursing care of a child, Pre-operative and Post-oper...

Pre-operative and Post-operative Nursing Care of a Child with Cleft Lip: We shall begin with pre-operative nursing care and then focus on post-operative care. As you know that

The heart, Ask question #Minimum 100 words adccepted#

Ask question #Minimum 100 words adccepted#

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