Chapter 5.1 Flashcards
1
Q
Describe the general structure of peptide hormones
A
- they are made up of amino acids
- > range from small size to relatively large ones
- note that peptide hormones are all derived from larger precursor polypeptides
- > that are cleaved during posttranslational modification
2
Q
How does cAMP work? What does it bind to?
A
- it works by phosphorylating intracellular targets
- > so it binds to targets such as protein kinase A and phosphorylates this target
-Kinase A can phosphorylate transcription factotrs like cAMP response element binding proteins(CERB)
3
Q
How long do the effects of peptide hormones last for? Also how do they travel in the body?
A
- the effects last for a short time
- > so constant stimulation of the receptors are needed for an effect
- they are water-soluble
- > so they travel freely in the bloodstream
- > do not need a carrier
4
Q
What is meant by the process dimerization
A
- it is a conformation change caused by steroids
- >where two receptor-hormone complexes are paired or linked once the steroid binds
5
Q
How do steroid hormones travel around the body? What does this mean for their activity levels?
A
- they are carried by carrier proteins around the body
- > therefore, they must dissociate from the carrier protein to be active and have a role in the body
- > higher amount of carriers= less free hormone available to have an effect
- some carrier proteins are very specific(sex hormone-binding globulin)
- > others are not very specific(albumin)
6
Q
What are the three types of hormones
A
-there are peptides, steroids, and or amino acid derivatives
7
Q
Give examples of amino-acid derivatives
A
Catecholamines
- > epinepherine and epinepherine
- > bind to G-receptors
Thyroid hormones
->bind intracellularly
8
Q
Where do tropic hormones usually originate from
A
- they usually originate from the anterior pituitary and the brain
- > tropic hormones require an intermediary to act unlike direct hormones
