5. Hormone signalling Flashcards
1
Q
What is ‘Signal Transduction’ ?
A
The mechanism responsible for transmitting extracellular signals across the plasma membrane and throughout the cell.
2
Q
What does Signal Transduction result in? Provide 4 examples
A
- Flux through metabolic pathways
- Ion flow through the plasma membrane
- Cell motility
- Gene expression
3
Q
Describe a simple cell signalling pathway (name 6 steps involved and the responses)
A
- Signalling molecule detected outside of the cell
- Signalling molecule binds to the receptor
- Signal transduction occurs (series of enzyme activations) and upstream signalling proteins
- Secondary messengers recruited to bind to downstream signalling proteins
- Phosphorylation of target proteins
- Responses e.g. covalent modifications, protein conformational changes or altered gene expression
4
Q
What is a Steroid hormone|?
A
a cholesterol- derived ligand which mediate hormone signals by altering the expression of a specific gene.
5
Q
Name the 4 steroid hormone categories and the roles they play
A
- Glucocorticoid; regulates glucose metabolism
- Mineralcorticoids; salt and water balances e.g. aldosterone
- Androgens; development and maintenance of male characteristics in vertebrates e.g. Testosterone
- Estrogen; development and regulation of Female characteristics e.g. reproductive system; Estradiol
6
Q
What are synthetic hormones?
A
agonists which mimic the biological response of the hormone
7
Q
What is an ‘agonist’ ?
A
a chemical which binds to a receptor and activates the receptor to produce a biological response
8
Q
Name the 3 categories of hormones
A
- Endocrine (e.g. steroids)
- Paracrine (e.g. growth factors)
- Autocrine
