Chapter 8 - Caffeine
What is the half-life of caffeine in the blood?
2.5-7.5 hours
What is the lethal dose of caffeine for adults? For children?
10 grams; 100 mg/kg for children
How long until caffeine reaches its peak effect?
15-45 minutes
When was coffee introduced to Europe?
1600s
How much caffeine do you have to consume in a day to have caffeine intoxication (caffeinism)?
600-1000 mg/day
Estimates are that __________ of the world's population regularly consumes products containing caffeine.
90%
Around what time and in what country was coffee introduced?
900 AD Arabia
Which of the following contains the highest concentration of caffeine? A. Brewed coffee B. Brewed tea C. Coca-cola D. Red Bull
A. Brewed coffee
Which adenosine receptors does caffeine block and what are the effects of those receptors when adenosine binds normally?
A1 and A2, makes you sleepy
Caffeine blocks receptors for which neurotransmitter?
Adenosine
What are the acute effects of caffeine?
CNS/cardiac/gastric acid stimulation, diuresis, relaxation of smooth muscle, opens airway slightly, increased vigilance and decreased fatigue
What is the greatest threat to coffee production?
Coffee beetles; eats the equivalent of 230 cups of coffee in a day
The most common reported withdrawal symptom of caffeine is ___.
Headaches
How does caffeine affect human task performance?
Increase in physical endurance, night vision, decision time (slower), vigilance and decreases in hand-eye coordination, reaction time (faster), fatigue
Caffeine is one of three naturally occurring compounds known as the __________.
Methylxanthines
What country is cacao from?
Mexico
Which popular soft drink contains the highest concentration of caffeine?
Mountain Dew
What natural plant sources have caffeine?
Tea leaves, cacao (chocolate), coffee beans, kola nuts (cola sodas), guarana, yerba mate, and more
Which country is the world's top coffee consumer?
The Netherlands
Where is most caffeine metabolized?
The liver
What are the other two methylxanthines besides caffeine?
Theophylline (found in tea) and theobromine (found in chocolate)
Physical dependence on caffeine can develop ____.
after 3 consecutive days of regular use
What are the symptoms of caffeinism?
arrhythmia, twitching, light flashes
What does caffeine block besides adenosine receptors?
cAMP phosphodiesterase which normally reduces cAMP production
Research has associated chronic caffeine use with __________.
elevated serum cholesterol levels
