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

Ascitic fluid collection - specimen collection, Pleural, Pericardial, and A...

Pleural, Pericardial, and Ascitic fluid Collection:      The procedure is called paracentesis . If for pleural cavity is called thoracocentesis , and for pericardial cavity c

State about visual system, State about visual system It is important fo...

State about visual system It is important for our visual system to  adapt to  recognize objects clearly  in  differing conditions of  light. The main mechanisms concerned with

Phylum ciliophora - protozoan, Phylum Ciliophora - Protozoan Simple ci...

Phylum Ciliophora - Protozoan Simple cilia or compound ciliary organelles typical in at least one stage of life cycle; subpellicular cilia present even if surface cilia are ab

How vitamins & minerals work together with nutrients in food, How Vitamins ...

How Vitamins and minerals work together with nutrients in food? Vitamins and minerals work together with nutrients in food. While antioxidant vitamins E and C and beta-carotene

Define the streak plate method - pure culture techniques, Define the Streak...

Define the Streak Plate Method - Pure Culture Techniques? The method was developed by Loeffler and Gaffkey in the laboratory of Robert Koch. The streak plate method depends on

Explain about the insulin syringe, Insulin Syringe To administer Insuli...

Insulin Syringe To administer Insulin properly, familiarize yourself with information about insulin: (a) insulin syringes, (b) storage, (c) site selection (d) steps for injecti

What is the group of the phylum chordata, What is the group of the phylum C...

What is the group of the phylum Chordata that first colonized the terrestrial environment? From which habitat did they come? Amphibians, partially aquatic partially terrestrial

What does acute disease mean, What does acute disease mean? An sharp di...

What does acute disease mean? An sharp disease is which does not last for a longer duration n has no weakness in the body

Explain about the imvic test, Explain about the IMViC Test? IMViC test ...

Explain about the IMViC Test? IMViC test is a combination of four tests: (1) Indole production (2) Methyl Red test (3) Voges Proskauer, and (4) Citrate Utilization

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