Peptide Hormones

Question 1

What is a hormone?

Answer 1

Chemical messengers which, speeding from cell to cell along the blood stream, may coordinate the activities and
growth of different parts of the body

Question 2

What are classes of hormones based on where they act?

Answer 2

1) Endocrine - distributed by blood
2) Paracrine - local communicator
3) Autocrine - hormone acts on the same cell that produced it

Question 3

What are classes of hormones based on synthesis?

Answer 3

1) Steroid hormones - cholesterol derivatives
2) Amino acid derivatives (epinephrine (adrenaline), thyroxine)
3) Fatty acid derivatives - ecosanoids, prostaglandins
4) Peptides and proteins

Question 4

What are the peptide hormones?

Answer 4

1) Tiny to large peptides
a) Thyrotropin-releasing hormone (TRH)
b) Adrenocorticotropic hormone (ACTH) aka corticotropin
2) Multi-subunit glycoproteins
a) Thyroid stimulating hormone (Thyrotropin, TSH)
b) Luteinizing hormone (LH)
c) Follicle-stimulating hormone (FSH)

Question 5

What are two types of hormone classifications based on membrane solubility?

Answer 5

1) Intracellular receptors is hormone is lipophilic or uncharged (Steroid hormones, thyroid hormone, retinoids, vitamin D)
2) Cell-surface receptors is for hydrophilic hormones or charged hormones (all the rest)

Question 6

What are the steps that allow a hormone to act?

Answer 6

1) binds to highly specific transmembrane receptors
2) signal is amplified by a second messenger or enzymatic cascades
3) the cell does something in response (grow or stop growing, synthesize or break down something, differentiate, survive or die)

Question 7

What is Albright Hereditary Osteodystrophy?

Answer 7

It is a type of pseudohypoparathyroidism (PHP) that characterizes a person as short stature, round face, & obese. Also causes subcutaneous ossification & ectopic bone formation