Human Electrochemical CellStudent Information Page 3C Part 1
Engagement part of Activity – The Energy Ball
Activity Introduction:Using the Energy Ball, students will work in groups to make observations about the way inwhich it works.
Materials:1 Energy Ball (per group of 5 students)
Procedure: 1. Have one student ‘play’ with the ball to try to make it glow.
2. As a group, decide what is happening to make the ball glow. Write down your observations and inferences on the Student Data Page. Try to explain what has caused the light to go on.
3. Now, make the Energy Ball glow with two students – each person can only touch one metal strip of the Energy Ball. On you Student Data Page, explain how you were able to accomplish the task.
4. Now everyone in your group must form a complete circuit to make the Energy Ballglow. Again, each person can touch NO MORE THAN 1 metal strip. On your Student Data Page, draw a diagram showing the arrangement of people and the Energy Ball.
5. On your Student Data Page, explain how the ball can light up when the whole group participates.
Explore Part of Activity – Does the Human Body Have Electricity?
Activity Introduction:Did you ever think about how important electricity is in your daily life? Well, it just may bemore important than you realize. You are able to stay alive because of the electrical messagesin your body.
“Quick Signals”All animals that move have electricity in their bodies, says Rodolfo Llinas, a neuroscientist
at New York University’s School of Medicine. Everything we see, hear, and touch gets translated into electrical signals that travel between the brain and the body
via special nerve cells called neurons.
Electricity is the only thing that’s fast enough to carry the messages that make us who we are,Llinas says. “Our thoughts, our ability to move, see, dream, all of that is fundamentally
driven and organized by electrical pulses,” he says. “It’s almost like what happens in a computer but far more beautiful and complicated.”
By attaching wires to the outside of the body, doctors can monitor the electrical activity inside. One special machine records the heart’s electrical activity to produce an electrocardiogram
(EKG)—strings of squiggles that show what the heart is doing. Another machine produces a pattern of squiggles (called an EEG) that represents the
electrical activity of neurons in the brain.
This recording of brain waves, called an EEG, represents the electrical activity of neurons in the brain.
One of the newest technologies, called MEG, goes even further. It actually produces maps of magnetic fields caused by electrical activity in the brain, instead of just squiggles.
Recent observations of patterns of nerve-cell action have given scientists a much better viewof how electricity works in the body, Llinas says. “The difference between now and
20 years ago is not even astronomical,” he says. “It’s galactic.”
Now, researchers are looking for new ways to use electricity to help people with spinalinjuries or disorders of the nervous system, such as Parkinson’s disease,
Alzheimer’s disease, or epilepsy.
People with Parkinson’s disease, for example, often end up having tremors and being unable to move. One type of treatment involves drugs that change the way nerve cells communicate
with each other. As part of another new treatment, doctors put tiny wires on the head that send electrical impulses into the patient’s brain. “As soon as you put that in,”
Llinas says, “the person can move again.”
Philip Kennedy at Emory University in Atlanta has even invented a kind of “thought control” to help severely paralyzed people communicate with the outside world. His invention, called a neurotrophic electrode, is a hollow glass cone filled with wires and chemicals.
With an implanted electrode, a patient who can’t move at all can still control the movement of a cursor across a computer screen.
Portion of an article called “Electricity’s Spark of Life”by Emily Sohn taken from the Science News for Kids website:
Materials (per group):• 1 bottle electrode gel (to make the gel, see instructions on
Teacher Information Page)• 1 Multimeter (Radio Shack 18-Range analog Multimeter –
Part #22-223 suggested)• 1 Copy of Student Information Card Multimeters as Ammeters
(per group or station)• 1 Copy Student Information Page• 1 Copy Student Data Page (per student)• Baby wipes (to clean gel from hands)
Procedure:1. Read the Multimeters as Ammeters card and follow the directions in it.
Explain part of Activity: How can humans become better batteries?
Activity Background:An electrochemical cell is a form of battery, composed of an electrolyte and electrical conductors. An electrolyte is a substance that contains atoms or groups of atoms with acharge (ions) and conducts electricity. Electrical conductors are materials that allow chargedparticles, such as electrons, protons, or ions to flow through them. When solid metal conductors are used, the flow of charged particles will involve only electrons. In the human body, the flow of charged particles consists of ions.
Batteries contain two electrical conductors (usually different types of metal) and they arecalled the electrodes. The electrodes will react chemically with the electrolyte (such as batteryacid), and this chemical reaction causes an electrical charge. Different combinations of metalswill develop different amounts of electrical charge. This difference in charge will allowcharged particles (in this case electrons) to flow from metal A to metal B. The micro-ammeteris a device when placed in a circuit can detect the amount of current (flow of electrons) inthis circuit. See Figure 1.
Materials:• 2 Pieces of metal (as provided by your teacher)• 1 Analog multimeter (Radio Shack 18-Range analog Multimeter –
Part #22-223 suggested)• 2 Electrical wires (or the wires with attached alligator clips)• 1 Copy of Student Information Card Multimeters as Ammeters
(per group or station)• 1 Copy Student Information Page• 1 Copy Student Data Page (per student)• 1 Bottle Electrode gel (instructions for making this are provided in teacher directions)• Baby wipes (to clean gel from hands)
Procedure:1. Make sure you are familiar with the steps to using a multimeter provided in Student
Information Card Multimeters as Ammeters. You need to make sure your dial is set at the 50 μA setting. You will be reading the black DC scale that reads 1 through 5 under red AC scale. The red AC scale is directly below the mirrored portion of the scale. With this setting each number represents 10 μ amps. i.e. 1.2 would represent 12 μ amp.
2. Select two pieces of metal (provided by your teacher) for your group.
3. Attach one end of an electrical wire to one piece of metal. Make sure to make a good contact (metal touching metal).
4. Using the other end of the electrical wire, attach it to one of the metal portions of the multimeter probe. Make sure to create a good contact (metal touching metal).
5. Repeat steps 2 – 4 by attaching the electrical wire to another piece of metal and the other metal portion of the multimeter probe.
6. Depending upon the size of the metal pieces, either grab a metal piece in each hand or place each hand flat on the surface of the two pieces of metal. In either case, make sure there is as much skin touching the metal as possible.
7. Observe the multimeter. Record your data on the Student Data Page. Be sure to record which metals are being used in each hand and record the amount of μ amps you observed.
8. Repeat this procedure making sure to use as many combinations of metals as possible.
9. Repeat steps 4-8 but this time place some electrode gel on your thumb and index finger where they will be touching the metal (or on the flat of your hand is you are laying your hand on a large piece of metal.) Record your need readings in the chart you have already created.
10. Try to make a circuit with two people so that you still get a measurable current.
11. See how many people you can put into your circuit and still have a measurable current.
12. When you have completed step 11, use the baby wipes to clean your hands and the electrodes.
