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 mechanism of absorption of haem iron, Explain Mechanism of Absorpti...

Explain Mechanism of Absorption of Haem Iron? Haem iron is soluble in the alkaline environment of the intestine. It binds to the receptor on the enterocytes and is internalized

Explain significance of mitosis for embryonic development, Q. What is the s...

Q. What is the significance of mitosis for the embryonic development? Every embryo grows from a single cell that bears mitosis and generates other cells that also divide themse

Clinical criteria for diagnosis of infective endocarditis, Major Criteria ...

Major Criteria 1) Positive blood culture • Typical microorganism for infective endocarditis from two separate blood cultures Viridans streptococci, Streptococcus bovis, HAC

Chlorocruorins - respiratory pigments, Chlorocruorins - Respiratory Pigment...

Chlorocruorins - Respiratory Pigments These types of respiratory pigments are found in four polychaete families: Sabellidae, Serpulidae, Ampharetidae and Chlorhaemidae. The pi

How would you perform abo blood grouping, Question 1 How would you perform...

Question 1 How would you perform ABO blood grouping? Add a note on advantages and disadvantages of each method. Also discuss the precautions you may take to avoid errors in variou

Name the term concerning with genetic principals of humans, Which of the be...

Which of the below refers to science concerned with the application of genetic principles to improvement of the human species? a) Eugenics b) Assortive mating c) Holandri

Control of excretion, CONTRO L OF EXCRETION - 1.      In brain hypoth...

CONTRO L OF EXCRETION - 1.      In brain hypothalamus is osmocentre that controls minerals. 2.      Cells of DCT & arterioles combien to form Juxta glomerular node, it se

State the term - antecedent and consequence control, Antecedent and consequ...

Antecedent and consequence control Therapy and consultation cannot be effective unless the behaviours to be changed are understood within a particular context. The process of u

Lysosomes, Lysosomes Lysosomes are small vesicles which are bounded ...

Lysosomes Lysosomes are small vesicles which are bounded by a single membrane & contain hydrolytic enzymes in the form of minute crystalline or semi crystalline granules of

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