Correct the following statements by replacing the term underlined.
(a) Insulin is a steroid hormone.
(b) TSH is secreted from the corpus luteum.
(c) Tetraiodothyronine is an emergency hormone.
(d) The pineal gland is located on the anterior part of the kidney.
(a) Insulin is a peptide hormone
(b) TSH is secreted from the pars distalis region of pituitary.
(c) Adrenaline is an emergency hormone.
(d) The adrenal gland is located on the anterior part of the kidney.
Match the following columns.
| Column I | Column II | ||
|---|---|---|---|
| A. | Oxytocin | 1. | Amino acid derivative |
| B. | Epinephrine | 2. | Steroid |
| C. | Progesterone | 3. | Protein |
| D. | Growth hormone | 4. | Peptide |
The correct matching is as follows
| Column I | Column II | ||
|---|---|---|---|
| A. | Oxytocin | 1. | Peptide |
| B. | Epinephrine | 2. | Amino acid derivative |
| C. | Progesterone | 3. | Steroid |
| D. | Growth hormone | 4. | Protein |
The hormones that are derivatives of amino acids, polypeptides or proteins are called peptide hormones. These being insoluble in lipids can not enter the target cell.
These act at the surface of target cell as primary messengers and bind to the cell-surface receptor forming the hormone-receptor complex.
It involves following steps
(i) Hormone called first messenger attaches to the cell surface receptor protein on the outer surface of plasma membrane of the target cell, forming a hormone-receptor complex.
(ii) This complex activates the enzyme adenyl cyclase.
(iii) Adenyl cyclase catalyses the conversion of ATP to cyclic AMP on the inner surface of plasma membrane.
(iv) cAMP serves as the second messenger or intracelluar hormonal mediator delivering information inside the target cells. This activates appropriate cellular enzyme system by cascade effect. Which induces the cell machinery to perform its specialised function.
(v) cAMP has a very short existence. It is rapidly degraded by the cAMP phosphodiesterase. Water soluble hormones, such as amines, peptides, proteins and glycoproteins exert their control through the cyclic AMP. These are quick acting hormones and produce immediate effect.
On an educational trip to Uttaranchal, Ketki and her friends observe that many local people were having swollen necks, Please help Ketki and her friends to find out the solutions to the following questions.
(a) which probable disease are these people suffering from?
(b) How is it caused?
(c) What effect does this condition have on pregnancy?
(a) People with swollen necks are suffering from goitre due to deficiency of iodine in the their bodies.
(b) Iodine is essential for the synthesis of thyroid hormones- $T_3$ and $T_4$ which are iodinated forms of tyroxine. Deficiency of iodine in our diet results in hypothyroidism and enlargement of the thyroid gland occurs place.
(c) Hypothyroidism during pregnancy causes defective development and abnormalities in growing baby like stunted growth (cretinism) mental retardation, low intelligence quotient (IQ) abnormal skin, deafmutism, etc.