Hormones + Regulation Of Blood Glucose Concentration Flashcards
What are the two principal coordinating systems in animals?
The nervous system and the hormonal system
How does the nervous system communicate and how does this differ from the hormonal system?
The nervous system communicates rapidly, while the hormonal system usually communicates more slowly
What is an example of hormonal interaction in maintaining homeostasis?
The regulation of blood glucose is an example
What is the primary function of the nervous and hormonal systems?
To maintain the constancy of the internal environment and respond to changes in the external environment
Why is the interaction between the nervous and hormonal systems important?
It allows the body to coordinate rapid and long term responses to internal and external changes
Where are hormones produced and how are they secreted?
Hormones are produced in endocrine glands, which secrete the hormone directly into the blood
How are hormones transported to their site of action?
Hormones are carried in the blood plasma to target cells
What is a key feature of target cells that allows hormones to act on them?
Target cells have specific receptors on their cell - surface membranes that are complementary to a specific hormone
How effective are hormones in terms of concentration?
Hormones are effective in very low concentrations
What type of effects do hormones typically have?
Hormones often have widespread and long - lasting effects
What is the second messenger model of hormone action?
It is a mechanism used by hormones like adrenaline and glucagon to regulate blood concentrations
What happens when adrenaline binds to its receptor?
The protein receptor changes shape on the inside of the membrane
What dopes the active protein kinase enzyme do?
It catalyses the conversion of glycogen to glucose
What does adenyl cyclase do after activation?
It converts ATP to cyclic AMP (cAMP)
What role does cyclic AMP (cAMP) play in this mechanism?
cAMP acts as a second messenger binding to protein kinase enzymes and activating it by changing its shape
What des adrenaline bind to initiate the second messenger model?
Adrenaline binds to a transmembrane protein receptor within the cell - surface membrane of a liver cell
What enzymes is activated by the shape change in the receptor protein?
Adenyl cyclase is activated
How does the glucose produced leave the liver cell?
Glucose moves out of the liver cell by facilitated diffusion through channel proteins and into the blood
Outline the full second messenger model involving adrenaline:
(6 steps)
- Adrenaline binds to a transmembrane protein receptor within the cell - surface membrane of a liver cell
- Binding of adrenaline causes protein to change shape on the inside of the membrane
- Change of protein shape leads to activation of adenyl cyclase (enzyme).
- The activated adenyl cyclase converts ATP to cyclic AMP (cAMP)
- The cyclic AMP acts as a second messenger that binds to protein kinase enzyme, changing its shape and therefore activating it
- The active protein kinase enzyme catalyses the conversion of glycogen to glucose which moves out of the liver cell by facilitated diffusion and into the blood, through channel proteins
