It wakes you up, gets you going, and may even cure your headache. But how much do you really know about caffeine?
Question 1 of 10
What percentage of Americans consume caffeine every day?
... Around 90 percent of Americans consume caffeine daily in one form or another. Over half of all American adults consume more than 300 milligrams of caffeine every day, making it the most popular drug in the United States.
Question 2 of 10
What is caffeine's medical name?
... Caffeine is known medically as trimethylxanthine. When isolated in its pure form, caffeine is a white crystalline powder that tastes very bitter.
Question 3 of 10
How many milligrams of caffeine does the average 6-ounce cup of coffee contain?
... Typical drip-brewed coffee contains 100 milligrams per 6-ounce cup. If you're buying your coffee at a coffee shop or drinking it out of a mug or a commuter's cup, you're consuming it in 12-, 14- or 20-ounce containers. You can calculate the number of milligrams based on your normal serving size.
Question 4 of 10
What sleep-inducing chemical does caffeine block from binding to nerve cells?
... To a nerve cell, caffeine looks like adenosine and binds to the adenosine receptor. However, caffeine doesn't slow down the cell's activity like adenosine would.
Question 5 of 10
Which neurotransmitter, or chemical messenger, does caffeine stimulate?
... Caffeine increases dopamine, which is a neurotransmitter that activates the pleasure center in certain parts of the brain.
Question 6 of 10
How long does it take your body to rid itself of just half the caffeine you consume?
... The half-life of caffeine in your body is about six hours. That means that if you consume a big cup of coffee with 200 milligrams of caffeine in it at 3 p.m., about 100 milligrams will still be in your system at 9 p.m.
Question 7 of 10
Which is not an effect of caffeine?
... Caffeine causes your blood vessels to constrict, which is why your hands get cold, your muscles tense up, you feel excited and you can feel your heart beat increasing after consuming a big cup of coffee.
Question 8 of 10
How might caffeine help cure a headache?
... Since caffeine causes your blood vessels to constrict, it can limit the amount of blood flow to the achy area and relieve the pain.
Question 9 of 10
Which of these is a symptom of caffeine withdrawal?
... Once you're addicted to caffeine, you have to keep taking the drug. If you try to stop your caffeine intake, you might get tired, depressed and a terrible headache as blood vessels in the brain dilate.
Question 10 of 10
Which illegal drug has a similar effect as caffeine on your body?
... Caffeine is an addictive drug. Among its many actions, it operates using the same mechanisms that amphetamines, cocaine and heroin use to stimulate the brain.
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