Action of Epinephrine on a Liver Cell


What are the effects of epinephrine? Epinephrine is a hormone and a neurotransmitter. It is secreted in the medulla of the kidney. The primary function of epinephrine is in the ‘flight or fight’ response to short term stress. Epinephrine has a variety of effects in different areas of the body including the breakdown of glycogen to glucose, the release of glucose into the body, increased heart rate, increased breathing rate, increased metabolic rate, increased flow of blood to the brain and skeletal muscles, and decreased flow of blood to the digestive system. All of these changes allow the body to respond quickly to any external danger.

View the animation below, then complete the quiz to test your knowledge of the concept.


Question 1

Epinephrine binds to
A) α-adrenergic receptors on the cell membrane of liver cells.
B) α-adrenergic receptors in the cytoplasm of liver cells.
C) β-adrenergic receptors on the cell membrane of liver cells.
D) β-adrenergic receptors in the cytoplasm of liver cells.
E) β-adrenergic receptors in the nucleus of liver cells.

Question 2

The binding of epinephrine to its receptor activates ________ which in turn activates ________.
A) protein kinase A ; G protein
B) protein kinase A ; adenylyl cyclase
C) adenylyl cyclase ; G-protein
D) G-protein ; adenylyl cyclase
E) G-protein ; protein kinase A

Question 3

The enzyme phosphorylase catalyzes the conversion of
A) glycogen into glucose-6-phosphate.
B) glycogen into glucose.
C) glucose into glycogen.
D) glucose into glucose-6-phosphate.
E) glucose-6-phosphate into glycogen.

Question 4

Epinephrine causes the liver to uptake glucose from the bloodstream during the fight-or-flight response.
A) True
B) False

Question 5

The conversion of ATP into cAMP is catalyzed by the enzyme adenylyl cyclase.
A) True
B) False