Sorry b, gonna need to know that the observations are.
Answer:
The correct answer is: β1 adrenergic receptor activation. Increased in cAMP lead to increased amounts of Na influx (though if channels) and calcium influx of pacemaker cells. This increases the frequency of APs of the pacemaker and increases the rate of contraction.
Explanation:
cAMP generated in response to β1 adrenergic receptors,results in excitation contraction coupling by initiating PKA and causing phosphorylation of L type Ca2+ channels and ryanodine receptors. This increases the concentration of intracellular Ca2+ ions in atrial cells, ventricular cells and AV pacemaker cells. This increase in firing rate. As a result rate of contraction increases.
Why is it important?
- Because when bacteria converts ammonia into nitrate and nitrite, producers need them to make proteins and then consumers eat the producers and reuse the nitrogen to make their own proteins.
2 according to the internet