Hard Biology question?

Question

Describe cell signalling effects of caffiene that relate to its role as a stimulant.

Answer 1

I am an MD. Caffeine is a phoshodiesterase inhibitor, meaning it blocks the degradation of cyclic AMP. Since the more cyclic AMP a cell has usually dictates how much activity there is in various cellular functions, the blocking of its degradation results in higher concentrations of it and thus more activity and thus it is a stimulant. I hope this helps.

Answer 2

1. Caffeine has the ability to manipulate dopamine production. Dopamine, a neurotransmitter, activates the "pleasure centers" in certain parts of the brain, and simply makes a person feel good.

2. Caffeine's chemical structure closely resembles adenosine and therefore binds to adenosine receptors in the brain. The net effect is that it blocks adenosine’s ability to slow the nerve cell activity. Caffeine causes blood vessels to constrict. During this time the pituitary gland sees all the chemical reactions as a bodily emergency and releases hormones that tell the adrenal glands to produce adrenaline also known as epinephrine. Adrenaline, the “flight or flight” hormone gives the users body a temporary heightened alertness. When epinephrine is released your pupils dilate, breathing tubes open up, heart rate increases, blood vessels constrict to slow blood flow and increases blood flow to muscles causing blood pressure to rise.

Hope this helps.