Final answer:
Caffeine increases blood glucose levels by blocking adenosine receptors and stimulating epinephrine release, leading to increased energy metabolism and alertness.
Step-by-step explanation:
Caffeine blocks a number of metabolic pathways, resulting in an increase in blood glucose levels, which in turn cause cells to increase their energy production. This is because caffeine acts as a central nervous system stimulant by inhibiting the action of adenosine, which normally promotes sleep and suppression of arousal. By blocking these adenosine receptors, not only are you more alert due to the effects on the brain, but the body also responds by releasing epinephrine (adrenaline), which triggers a signaling pathway in the liver, leading to the breakdown of glycogen into glucose, thus increasing blood glucose levels.
The increase in blood glucose is particularly resourceful for muscles, especially during the 'fight or flight' response, fueling muscles with the energy required for quick, short-term responses.
Thus, consuming caffeine can cause an increase in blood glucose, contributing to heightened energy metabolism and increased alertness, as well as potential side effects such as anxiety and insomnia if consumed in high doses.