Question

Evaluate your knowledge of the chemical classes of hormones by classifying the following statements as being descriptive of peptide/catecholamine hormones or steroid/thyroid hormones.

Answer 1

Peptides/catecholamines

1. Transported freely dissolved in the blood plasma
2. Synthesized in endoplasmic reticulum and golgi complex
3. Usually have a fast effect and are metabolized and excreted quickly
4. Packaged into secretary vesicles by the golgi apparatus   and many are stored as prohormones
5. Receptors site is the usually the plasma membrane of target cells
6. Usually have a slow effect and are metabolized and excreted slowly
7. Initiate second messenger signaling cascades or enzymatic activation by the receptors
8. Hydrophilic / lipophobic
9. Secreation occurs via exocytosis of pre-packaged vesicles upon stimulation

Steroids/ thyroids hormone

1. Synthesized by modification of cholesterol or tyrosine
2. Require proteins carriers to be transported in the blood plasma
3. Initiate changes in a gene transcription
4. Canot be stored in vesicles must be stored in colloid or synthesized upon stimulation
5. Hydrophobic / lipophilic
6. Receptors site is inside target cells usually in the nuclei
7. Are membrane permeable so the rate of secretion usually equals the rate of synthesis