• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Experiment - Influencing the Rate of Photosynthesis with Light Intensity and Carbon Dioxide Concentration

Extracts from this document...


Aylin Humzeli April, 07 2011 Influencing the Rate of Photosynthesis with Light Intensity and Carbon Dioxide Concentration Introduction Background: Photosynthesis is the process plants use to produce organic molecules, usually carbohydrates, from carbon dioxide and water by using sunlight or an alternative source of light. The light is used as energy which is absorbed by chlorophyll in the chloroplast of plants. Photosynthesis is comprised of two different reactions: the light-dependent reaction and the light-independent reaction. The light independent reaction is powered by light energy and produces ATP and NADPH, as well as oxygen as its waste product. The light independent reaction is powered by the NADPH produced in the light dependent reaction and produces sugars using carbon dioxide. The general formula for photosynthesis is: 6H2O + 6CO2 + Energy ==> 6O2 + 2 C3H6O3 The rate of photosynthesis can be affected by 3 factors: light intensity, carbon dioxide concentration, and temperature. An increase in light intensity increases the energy absorbed by the chlorophyll, and hence increases the rate of photosynthesis to a point. Increase in the amount of carbon dioxide increases the amount of carbon dioxide available to the enzymes to catalyze. Carbon dioxide concentration increases the rate of photosynthesis only to a point, specifically, when the enzymes are saturated. Since photosynthesis depends on enzymes, an increase in temperature increases the rate of photosynthesis to a point, for the enzymes have reached their optimum temperature. ...read more.


Uncertainties: The distance between the lamp and the test tube was measured with a normal metric ruler. The ruler's smallest measurement was 0.1, half of this is 0.05 which is the ruler's uncertainty. The uncertainty for time was 0.01 seconds which is the smallest unit measurable with a digital stop watch. The uncertainty for the amount of sodium bicarbonate is 0.01 grams which is the smallest value measurable with a digital scale. Results: The data and graph show that when the distance of the lamp is 5 cm and sodium bicarbonate is added the average number of bubbles produced is the highest. The average number of bubbles produced is followed by the lamp at 5 cm without sodium bicarbonate. The condition with the lamp 20 cm away produced the smallest number of bubbles. The second trial of the lamp at 5 cm away produced more bubbles. The second trial for the condition of 20 cm distance produced less bubbles than the first trial. The second trial with the lamp at 5 cm and with sodium bicarbonate produced a lower number of bubbles than the first trial. Conclusion: As the graph shows, the most bubbles were produced when the light intensity was closest, at 5 cms, and when sodium bicarbonate was added. The least amount of bubbles was produced when the light source was 20 cm away and with no sodium bicarbonate added. ...read more.


For more accurate average, more trials should be done. This would decrease the amount of deviation of the number of bubbles produced and would produce a better average value. Unfortunately, the error which comes from using the same elodea cannot be reduced. For using a different plant for each experiment would also affect the data for the plant would vary in surface area and freshness. However, the data still did allow one to see the effect of each condition correctly. Instead of counting the number of oxygen bubbles produced, the test tube would the elodea could be covered so that no gas escapes. The test tube could then be connected to a beaker which is on scale or another instrument to measure mass. Then as the plant produces oxygen, the mass produced could be measured rather than having to count the bubbles which can be affected by human error. Since the objective of the lab is to observe how factors influence the rate of photosynthesis. The experiment could be extended so that it also observes how temperature affects the rate of photosynthesis by submerging the plant in different temperature water. Also, instead of just using white light, different colored lights or transparent glossy paper to see the affect of different colored light on plants. Also, a wider number of distances would improve the experiment for it would provide better accuracy of how light intensity affects the rate of reaction. ?? ?? ?? ?? 1 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Biology HL IA - Photosynthesis of elodea lab report

    too distant to obtain a real-life graph in order to see in the optimum light intensity. To improve the accuracy of the results, the readings would have to be taken several more times.

  2. affect of light intensity on rate of photosynthesis

    This keeps the concentration of NaHCO3 (which supplies CO2) constant; therefore increase accuracy of the result. If NaHCO3 was put in different amount into each beaker, the measure of pH change will be different. * The solution in each beaker was tested for pH before the experiment to ensure they

  1. Extended Essay- How is production of carbon dioxide (CO2) during digestion affected by the ...

    As stated before, carbohydrate compounds consist of simple and complex forms. Simple carbohydrates are composed of monosaccharide or disaccharide units. Glucose, fructose, and galactose are monosaccharides, or simple sugars. Glucose is the most common type of sugar and it's the primary form of sugar that is stored in the body

  2. Environmental Factors affecting plant growth

    During the experiment, I faced a few problems. The first one would be that I was not able to take results regular bases. This could be problem because this way I do not know the small changes that the plant while growing.

  1. The effect of toliet cleaning products on E-coli ...

    In future experiments the grid square crossover method should be used as it creates colonies from the same source in a single continues stroke rather than the random movements seen in the spread method. Also the agar plates themselves where often moved.

  2. Effect of Incandescent, Fluorescent and LED lights at 900 lumens on the concentration of ...

    ________________ This will be done by starting a 15-minute timer the moment the ascorbic acid solution sample is placed under the type of light ________________ A time frame is placed on the duration at which solution of vitamin C is placed under the light so all samples get an equal amount of light penetration.

  1. How does changing the percentage of sucrose added to yeast affect the rate of ...

    were able to ensure greater reliability of our results, during our trials for 20% sucrose we recorded a result which did not correlate to the rest of the results for that trial (3mm in comparison to approximately 17mm), we were able to do a sixth trial and replace the outlier

  2. The Light Dependent Reactions of Photosynthesis

    Rather, this energy is converted into a form that the plant can store and use to drive cellular reactions. Put simply, photosynthetic organisms convert light energy into chemical energy. In photosynthesis, the main energy-containing chemical produced is glucose, a simple sugar.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work