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

Explain the dietary modifications - obesity, Explain the Dietary Modificati...

Explain the Dietary Modifications - Obesity? The dietary modifications serve as a guide for the obese to make healthy food choices. The first step towards prescribing a diet fo

What is the function of the flagellum of the sperm cell, What is the functi...

What is the function of the flagellum of the sperm cell? How is it formed? The flagellum of the sperm cell is produced by the centrioles that migrate to the region posterior to

Precaution for determination of haemoglobin content in blood, Define Precau...

Define Precautions for Determination of Haemoglobin Content in Blood 1. Potassium cyanide is highly toxic and hence drabkin's solution should not be pippeted by mouth. 2. Dr

Bracketed keys to identifying plants and animals, Q. Bracketed Keys to iden...

Q. Bracketed Keys to identifying plants and animals? In bracketed keys two couplet leads of the same rank are bracketed together. The alternative clues or couplets are written

Why the effect of genetic drift likely to be the same, Is the effect of gen...

Is the effect of genetic drift likely to be the same in pop 1 and pop 2? How are genetic drift and pop size related? When there is strong selection against the homozygous recessive

Explain microbiology of soil, Q. Explain microbiology of Soil? Ans. ...

Q. Explain microbiology of Soil? Ans. You would realize that the soil contains greatest varieties of microorganisms. It actually serves as a medium for growth and developm

What best describes the amoebas division, What best describes the amoebas d...

What best describes the amoebas division?  (1) It is a Mode of asexual account in which a one parent is involved. The amoeba cell, which is unicellular, separates into two daug

Explain oxidative phosphorylation, Explain Oxidative phosphorylation ...

Explain Oxidative phosphorylation Oxidative phosphorylation  : Synthesis of ATP  from ADP  and  Pi  during the passage of electrons in the respiratory chain.

Chemical methods of estimating available nutrients, Chemical Methods of Est...

Chemical Methods of Estimating Available Nutrients  Water soluble forms of nutrients are available to plants but forms other than water soluble may also become available to pla

What happens within the cell in the first interface period, What are the ev...

What are the events that mark the beginning and the end of the first interphase period? What happens within the cell in this period? The first interphase period is the G1. It s

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