Investigating the factors that may affect a persons heart rate.

Drug Taking - Alcohol, cigarettes and drugs will lower your fitness. Drugs are chemical substances that can affect the way your body works. All drugs are dangerous when misused. Some types of drugs are: Stimulants (These stimulate the circulatory and nervous system. They raise your heart rate and blood pressure), Narcotic Analgesics (These are painkillers, they are mainly a means of drowsiness) and Antibiotic Steroids (These are the hormones which will help to build and repair muscle and bone, they occur naturally in the body).

The Environment- Fumes from factories and traffic, over long periods, will damage your lungs and make breathing difficult. Your fitness will therefore suffer.

Respiration :

 Apparatus:

For this specific experiment I will need the following apparatus:

• One measuring cylinder - I will need just the one because the only chemical that I am measuring is Hydrogen Peroxide.
• Five Test Tubes (Five Test Tubes fro each of the factors that I was testing - We needed five to speed up our experiments and save time as we only had one hour to conduct all our experiments. We did two simultaneously as I had my partner to conduct another experiment at the same time.
• Four Water Baths – These four water baths are all at different temperatures, (00C, 400C, 600C and 1000C). There will also be an experiment conducted at room temperature, which will obviously not need a water bath.
• Scalpel - I needed a scalpel in order to cut the potato into the correct segments of      1 cm3.
• Stop Watch – This will be used to measure the reaction time between the two different substances.
• Thermometer- This will be used to check the temperature of the water baths. This will be essential as to make my experiment a fair and accurate one.

Prediction:

Testing For Temperature.

For this experiment I predict that as the temperature increases, the reaction time of the experiment will therefore decrease. When the temperature is increased the particles all move quicker. If they move quicker there will be more effective collisions. This will take place until the reaction gets to an optimum temperature at which the Hydrogen Peroxide particles will denature This will mainly be due to more and more kinetic energy being produced as the temperature rises. I came to this conclusion from my scientific knowledge.

As the temperature increases the Hydrogen Peroxide particles will get charged up and therefore collide into other Hydrogen Peroxide particles and more likely with the potato it’s meant to react with. Due to the Hydrogen Peroxide particles colliding more frequently with the potato, there will be a lot of oxygen being given out. This will take place because Oxygen is a buy product of the reaction.

Also for temperature, I need to take into account ‘The Lock and Key Theory’. Enzymes are affected a great deal by temperature. Enzymes are proteins, at a high temperature the protein breaks down. This means that the active site is changed, so the substrate no longer fits the enzymes active site. The enzyme is now known to be denatured, so therefore no longer works.  

Testing For Surface Area.

When testing for surface area, I must take into account the collision theory.

From my knowledge of the collision theory, I know that if a solid (This case potato) is broken down into smaller pieces, it will increase its surface area. This means that the particles around the potato in the solution will have more of an area to work on so there will be a lot more effective collisions. In this case there will again be more oxygen produced, as there is more collisions taking place. Therefore the reaction between the Hydrogen Peroxide and the living tissue will take place faster.

In general there are three ways that I can that I can tell that a gas (Oxygen) is given out:

1. Change in mass – Any reaction that produces a gas, can be carried out on a mass balance and as the mass disappearing is easily measured.
2. The volume of the gas given off – This will involve the use of a gas syringe to measure the volume of gas given off. As there are bubbles being produced I can tell that the reaction is still taking place.
3. Test For Glowing Splint – If we know that oxygen is given off, we can test this by blowing out a lit match and then exposing it to the oxygen, if oxygen is given off the match will then relight.

Method.

To do this experiment with the greatest accuracy the steps I will need to follow are:

1. Collect all the apparatus required to do the experiment.
2. Cut the potato into accurate 1 cm3 cubes with a scalpel.
3. Put one piece of the 1 cm3 potato into a test tube as to get the potato adjusted to the temperature conditions (If you were doing the experiment for temperature, other than room temperature).
4. Measure the correct volume of the Hydrogen Peroxide.
5. Pour the Hydrogen Peroxide into the test tube that already has the potato. Simultaneously, just as all the Hydrogen Peroxide has been poured into a beaker your partner should start the stop clock.
6. Once the reaction has stopped taking place jot down the time and record your results in a table.

Results.

Temperature:

 Surface Area –

Evaluation.

The people doing the breathing rate experiments are doing the experiment to see how fit each person is. They do this by timing how long it takes for their breathing rate to get back to their normal rate (the rate it was at before they started to do the exercise). The method they stated they would use is extremely vague and is not very concise. The experiment was to find the ‘effect’. The experiment could have been improved if they had a specific effect that they were going to measure. An example of this would be to find out if boys were better than girls at jogging for 5 minutes.

            There are also many things that are not fair about the test. Firstly, there is one male and two females. This means that if they were testing to see whether or not boys were fitter than girls they could get biased results. This would result because the two females they chose could be extremely fit and the male could be extremely unfit. To overcome this problem I would use an equal amount of males and females (5 males and 5 females). I would also make sure that each of the people being tested would have a uniform lifestyle. Although I could never be completely sure if they had the exact same lifestyle I would try to find the closest match. They also do not state which form of exercise they are doing and this means that one person could have been running at 5 miles per hour whilst another could have been cycling at 2 miles per hour. This meant that their method was not very suitable at all. I would change this by making them do a uniform exercise like jogging at 5mph. Other factors which made their method unsuitable were the way in which they measured the results. It looks as if they have asked each person to measure their own amount of breaths they have taken. I have come to this conclusion because Johns result seems to be anomalous. This was probably because he had measured his own result and had probably measured his exhaling separately from his inhaling. This would cause his results to double. A way to overcome this problem would be to use a heart rate monitor and a breath meter (respirator). This would guarantee that the results were accurate. I would also take an average by repeating the test at least 4 times. This would help me because one result may come out with odd results and this would be a way of making that result less affective. It would also ensure they were much more accurate.

            To extend the investigation I could do another experiment using people with worse lifestyles. I could then compare these results with the ones I had obtained in the previous test to see how peoples lifestyles affects their breathing rate. I could also use more people as the more results I obtain the more accurate the results will be.