Question

1. Describe the structural difference between protein hormones and steroid hormones.

Answer 1

Answer :

Protein Hormone : protein hormone or peptide hormones are hormones who molecules are peptides or proteins. Protein hormones are synthesized in cell from amino acids according to mRNA transcripts, which are synthezised from DNA templates inside the cell nucleus. Preprohormones, protein hormones precurrsors, are then processed in several stages, tyically in the endoplasmic reticulum, including removal of the N-terminal signal sequence and sometimes glycosylation, resulting in prohormones. The prohormones are then packaged into membrane-bound secretory vescicle, which can be secreted from the cell by exocytosis in response to specific stimuli (e.g. an increase in Ca²⁺ and cAMP concentration in cytoplasm).

The term steroid describes both hormones produced by the body and artificially produced medications that that duplicate the action for the naturally occuring steroids. Steroid hormones can be grouped into two classes :

• corticosteroids (typically made in the adrenal cortex,hence cortico-) and
• sex steroids (typically made in the gonads or placenta).

within those two classes are five types according to the receptors to which they bind :

• glucocorticosteroids
• mineralocorticosteroids
• androgens
• estrogens
• progestegens

Steroid hormones helps control metabolism, inflammation, immune function, salt and water balance, developmental of sexual charecteristics and the ability to withstand illness and injury.

Protein or peptide hormone

Whereas amine hormones are derived from a single amino acids, protein and peptide hormones consist of multiple amino acids that link to form an amino acid chain. Peptide hormone consist of short chains of amino acids, whereas protein hormones are longer polypeptides. Both types are synthesized like other body proteins: DNA is transcribed into mRNA, which is translated into an amino acid chain.

Steroid hormone :

Steroids pass into a cell nucleus, bind to specific receptors and genes and trigger the cell to make proteins. Steroid hormones derived from lipids. Reproductive hormones like testosterone and estrogen are steroid hormones.