The Chemistry of Energy Drinks

Here is the Chemistry part of the investigation. There will be a copy handed out to everyone who comes to our stall during the Science Group IV day.

WELCOME TO THE CHEMISTRY SECTION OF OUR PROJECT! Hope you enjoy reading about the Chemistry of these drinks and the investigation behind the science! Besides the biological factors concerning energy drinks with their effects on the human body, it is essential to highlight the chemistry of these drinks and how these substances interact to form what we know as "energy drinks".

What exactly are energy drinks?

Energy drinks provide energy to enhance physical activity of the drinker. Rather than consuming food, these drinks increase the drinker’s mental alertness and physical performance by addition of:
· Caffeine (central ingredient for most energy drinks)
· Vitamins
· Herbal supplements
These components interact to provide a stimulant effect on the human body.

What are stimulants?

Stimulants are a variety of compounds that excite the central nervous system or alter the body’s metabolism. They enhance alertness and increase the energy provided to the body.
Stimulants are very similar to hormones as they both have the same effect:
· Increase heart rate, increase blood pressure, and increased rate of respiration.
· They increase the breakdown of glycogen and glucose to meet the demands for energy.
· Increase the rate of neurotransmission through nerve cells.

Why is Caffeine the main ingredient in Energy Drinks?

Caffeine is the most widely used stimulant in the world. It is a diuretic and increases alertness, concentration, and restlessness. Caffeine is also an alkaloid (nitrogen-containing compounds of plant origin containing heterocyclic rings and a tertiary amine group). It must be highlighted that caffeine is used as a boost in energy drinks. The other components already give a stimulant effect. Caffeine simply boosts the effect to make the drink really energetic.

Fig 1. The structure of caffeine. The IUPAC (International Union of Pure and Applied Chemistry) name for this compound is: 1,3,7-trimethylpurine-2,6-dione. If you need help naming basic Chemical compounds, you can contact the Higher Level Chemist for more details.

What else is there in Energy Drinks?

Besides caffeine, there are several other different substances that make up energy drinks such as:

· Taurine Regulantes muscle contractions
· Guaraná
· B Vitamins
· Ginseng
· Gingko Biloba
· L-Carnitine
· Sugars
· Anti-oxidants
· Glucuronolactone

Please read our Biology information pack for more information on ingredients and effects on the human body.

Is there a difference between Energy Drinks and Sport Drinks?

Surprisingly yes, there is a clear distinct difference between Energy Drinks and Sport Drinks. Energy drinks supply energy to the human body as we lose a lot of “fuel” when doing vigorous exercise. They use primarily carbohydrates to supply the body with energy. However sports drinks have a different purpose. Sport Drinks have the function ofsupplying carbohydrates in a fast digesting form to supply energy to muscles so that you have something that will keep you going until the end of the day.

Sports drinks also supply some of the components we lose in sweat (fluids, sodium, and potassium) and intentionally avoid ingredients that could speed the rate of fluid loss, like caffeine.

What happens when you sweat?

When you sweat, it is inevitable that you lose a lot of fluids. This is to cool your body down! But the liquid that you are losing contains excretory material such as urea and lots of ions (such as Na+ and K+). This is where drinks are necessary to replace these things that have been lost with sweat.

Where does the Chemistry come into all of this?

As it has been seen, there are several important substances that are lost in sweat. The Chemistry side of the project is to see which energy drink replaces these substances lost the quickest. How will we do this? Simple. We are going to use a process known as electrolysis to measure the current that is conducted in solutions of different energy drinks and compare the results.

KEY WORDS:
electrolysis chemical decomposition reaction produced by passing an electric current through a solution containing (charged particles).

THE PROCESS OF ELECTROLYSIS

To understand the concept of electrolysis, we must look at a very simple diagram:

This shows a simple set up of an electrolysis experiment. Once the electricity is turned on, the electrolyte (liquid containing ions) will dissociate into ions. Depending on their charges, the ion will either go to the positive electrode or the negative electrode.

Solutions in water (ultimately energy and drinks) contain hydroxide and hydrogen ions as well as the ions of the solute (in this case potassium and calcium and many more!)

The ions that are successfully released at the electrodes depend on three factors:

Position of the ion in the electrochemical series

Concentration of the ion in the solution

The nature of the electrode

Depending on these 3 different factors, different reactions can occur at the electrodes. Here is an example of ionic equations of the electrolysis of Sodium Chloride (NaCl) solution.

Negative Cathode:

2(H+) + 2e ---> H2

Positive Anode:
2(Cl-) - 2e ---> Cl2

Now that we have covered the theory, we can go into what we are trying to prove.

Our hypothesis: The energy drink or sport drink that conducts the most electricity (has the highest current) is the better drink to use in sport.

We will measure the current that is conducted through the liquid by the use of an ammeter. We will build an electrolytic cell to do this:

THE CHEMISTRY OF ELECTROLYTIC CELLS
In a voltaic cell electricity is produced by the spontaneous redox reaction taking place. Electrolytic cells are used to make non-spontaneous redox reactions occur by providing energy in the form of electricity from an external source (like a power pack).

In an electrolytic cell electricity is passed through an electrolyte and electrical energy is converted into chemical energy. It is important to note that an electrolyte is a substance which does not conduct electricity when solid, but does conduct electricity when molten or in aqueous solution and is chemically decomposed in the process.

Here is a simple diagram representing an electrolytic cell of molten sodium chloride (not that the products are different to that of an aqueous solution):

However instead of using molten sodium chloride, we are going to be using energy drinks. Once the power pack is turned on, the ammeter should tell us a reading of the current passing through this cell. We will compare the current with all the different energy drinks and compare this to the other experiments we have on offer for you!

Have you ever seen an electrolysis experiment?
If this is your first time, you should expect to see a lot of fizzing (or effervescence). Expect to have a great time observing all the different electrolysis experiments going on at our stall. If you have any queries about the investigation or the Chemistry behind it, don’t hesitate to contact the Chemist representative of our group, Michael. He will be happy to ask any of your questions!

Please make sure you read the other information packs as they are updated! Watch this space!