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 pollen, What is pollen? Pollen grains are the male gametophytes...

What is pollen? Pollen grains are the male gametophytes of the phanerogamic (flowering) plants. Thus within the pollen grains the male gametes of these plants are produced by m

Describe the planes of muscles, Describe the Planes of Muscles The plan...

Describe the Planes of Muscles The planes of superior and inferior recti in primary position form an angle of about 23 0 with the Y-axis. Therefore, the axis of rotation of th

Explain about the smoking - methods of food processing, Explain about the S...

Explain about the Smoking - methods of food processing? Smoking was known as a method of food preservation at an early date. Foods are exposed to smokes by burning some special

Radiographic evaluation - criteria for endosteal implants, Radiographic Eva...

Radiographic Evaluation - criteria for endosteal implants Surgical and interventional imaging involves imaging the patient  during and immediately after surgery and during the

National health service systems, Normal 0 false false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Determine about the prokaryotes and eukaryote cell, Determine about the pr...

Determine about the prokaryotes and eukaryote cell The eukaryotic cells, on the other hand, have a true nucleus wherein the genetic material, DNA is enclosed within a well-def

Explain diseases of pericardium, Q. Explain Diseases of pericardium? Pe...

Q. Explain Diseases of pericardium? Pericardium is the sac covering the heart. Pericardium consists of two layers-the visceral pericardium (epicardium) and the parietal pericar

What is condition for the mendel''s second law to be valid, What is conditi...

What is condition for the Mendel's second law to be valid? The Mendel's second law is only valid for genes located in various chromosomes. For genes situated in the similar chr

Rational in individual patient, Thiazide diuretics have been accepted as th...

Thiazide diuretics have been accepted as the primary foundation of antihypertensive therapy. The basis of this choice is that, apart from their primary hypotensive effect, they enh

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