Caffeine, medically known as trimethylzanthine. Its chemical
formula is C8H10N4O2. When in pure form, caffeine is a white
crystalline powder that taste very bitter. The most common way of
acquiring pure caffeine is the process of decaffeinating coffee and
Caffeine is useful as a cardiac stimulant and also as a mild
diuretic. Cardiac stimulants increase the heart rate, and diuretics
increase urine production. Caffeine is also used to provide a “boost of
energy” or a feeling of heightened alertness.
Caffeine is an addictive drug. It operates using the same
mechanisms that amphetamines, cocaine and heroin use to stimulate
the brain. Caffeine’s effects are more mild than the above listed
drugs, but it is manipulating the same channels and this gives
caffeine its addictive qualities. If you feel like you cannot function
without it, then you are addicted to caffeine.
Caffeine occurs naturally in many plants, such as, coffee
beans, tea leaves and cocoa nuts. Caffeine is added artificially to
many products, including a variety of beverages. Below is a table of
products and the amount of caffeine in each.
Product Amount of Caffeine
Jolt and Similar Products 70 mg / 12 oz can
How does caffeine work? Your brain creates a chemical called
adenosine. This chemical binds to adenosine receptors in the brain.
The binding of adenosine causes drowsiness by slowing down nerve
To a nerve cell, caffeine looks like adenosine, and caffeine
binds to the adenosine receptors. The caffeine does not slow down
the cell’s activities like adenosine, but instead, speeds up the cell’s
activities. Caffeine also constricts the brain’s blood vessels. If you
have a vascular headache, caffeine can slow down the blood flow to
the brain and relieve it. Therefore, some headache medicines like
The pituitary gland sees all of the activity and thinks some sort
of emergency must be occurring and causes a release of the
hormone adrenaline. Adrenaline speeds up the bodies functions even
The most important long-term problem is the effect that caffeine
has on sleep. Adenosine reception is important to sleep, and
especially to deep sleep. If you drink a big cup of coffee with 200 mg
of caffeine in it at 3:00 PM, about 100mg is still in your system at 9:00
PM. You may be able to fall asleep, but you body probably will miss
out on the benefits of deep sleep. The deficit adds up fast. The next
day you feel worse, so you need caffeine as soon as you get out of
The Effects of Caffeine on Daphnia - An Experimental Investigation
Problem: Does caffeine effect the heartrate of daphnia?
Hypothesis: I believe caffeine, when added to the water daphnia is in,
Procedure: 1) Brew a strong pot of coffee to assure a response.
2) Extract a daphnia from the culture using the dropper.
3) Place the daphnia on the dish slide. Make sure the daphnia has
5) Count the heartbeats for 1 minute. Do this 2 times and get an
average. Record the bpms in the Data Table.
6) Add a drop of strong brewed coffee to the dish and quickly count
the number of heartbeats. Do this twice, get an average and record
7) Follow the above steps with 4 more daphnia.
Results:
Conclusion: My data shows that given a drop of coffee containing
caffeine, daphnia’s heart rate increased on average 18 beats per
minute. This proves my hypothesis to be correct.
Fox, Richard, Invertebrate Anatomy, Daphnia magna,
Caffeine as a Drug, www.bioone.org/doi/abs/10.1525/abt.2010.72.3.9
Marc GIRARD Mathématicien de formation, le Dr Girard est devenu médecin tout en menant des recherches sur la modélisation mathématique en biologie. Après un passage aussi bref que mouvementé comme salarié d’une grande firme pharmaceutique, il a développé, en France, la première activité libérale de conseil en pharmacovigilance (étude des effets secondaires des médicaments) et e
Economuse, 30 March 2007 Broadband – Picking winners or correcting failures? Is the ALP’s proposed national FTTN broadband network visionary nation- building or economic vandalism? I like it but more detail is required. Australia’s international ranking on broadband penetration is a cause of nationalembarrassment. More importantly, electronic communications is increasingly seen as a