Measuring the rate of photosynthesis Measuring the rate of photosynthesis Without photosynthesis life as we know it would not exist. Plant biomass is the food and fuel for all animals. Plants are the primary producers.
Measuring the rate of photosynthesis Measuring the rate of photosynthesis Without photosynthesis life as we know it would not exist.
Plant biomass is the food and fuel for all animals. Plants are the primary producers. These amazing organisms are capable of capturing the energy of sunlight and fixing it in the form of potential chemical energy in organic compounds.
The organic compounds are constructed from two principle raw materials; carbon dioxide and water which is a source of hydrogen. These compounds are stable and can be stored until required for life processes. Hence animals, fungi and non-photosynthetic bacteria depend on these for the maintenance of life.
But how can we measure the rates at which photosynthesis takes place? The quantities are mind boggling. There is a total of x tonnes of carbon dioxide in the atmosphere and photosynthesis fixes x tonnes per year.
What are the different methods of measuring the rate of photosynthesis?
There are a few key methods to calculate the rate of photosynthesis. Read the full protocol on using immobilsed algae to measure photosynthesis.
Using a CO2 monitor - More simply, you could put a plant in a plastic bag and monitor the CO2 concentration in the bag using a CO2 monitor.
Naturally, the soil and roots must NOT be in the bag as they respire. Alternatively, you could place some Bicarbonate Indicator Solution in the bag with the plant and watch the colour change.
This would best be done with a reference colour chart to try to make the end-point less subjective. This could give a comparison between several plants. The leaf area of the plants should be measured so you can compensate for plant size.
Atmospheric air is only ppm CO2, so there is not much CO2 to monitor and the plant will soon run out of CO2 to fix. Measuring photosynthesis via the production of oxygen Oxygen can be measured by counting bubbles evolved from pondweed, or by using the Audus apparatus to measure the amount of gas evolved over a period of time.
To do this, place Cabomba pondweed in an upside down syringe in a water bath connected to a capillary tube you can also use Elodea, but we find Cabomba more reliable. Put the weed in a solution of NaHCO3 solution. You can then investigate the amount of gas produced at different distances from a lamp.
Read a full protocol on how to investigate photosynthesis using pondweed. Measuring photosynthesis via the production of carbohydrates There is a crude method where a disc is cut out of one side of a leaf using a cork borer against a rubber bung and weighed after drying.
Some days or even weeks latera disk is cut out of the other half of the leaf, dried and weighed. Increase in mass of the disc is an indication of the extra mass that has been stored in the leaf.
This is very simple to do and enables you to investigate plants growing in the wild. However, you can probably think of several inaccuracies in this method.
If you harvest several plants and record how much mass they have accumulated you will have an accurate measure of the surplus photosynthesis over and above the respiration that has taken place.
As with most methods, you need several plants so you have replicate measurements and you can find an average and a standard deviation if necessary. Investigating the light-dependent reaction in photosynthesis The rate of decolourisation of DCPIP in the Hill Reaction is a measure of the rate of the light-requiring stages of photosynthesis.the rate of photosynthesis generally increases until limited by another factor.
As it is normally present in the atmosphere at very low concentrations (about %), increasing carbon dioxide concentration causes a rapid rise in the rate of photosynthesis, which eventually plateaus when the maximum rate of fixation is reached.
Rate of. This activity is a lab where students design an experiment to test the rate of photosynthesis. Students will analyze data,write a report using the scientific method, and apply results to current environmental issues. This activity is a lab where students design an experiment to test the rate of photosynthesis.
Students will analyze data,write a report using the scientific method, and apply results to current environmental issues. The measured rate of photosynthesis as a function of absorbed wavelength correlates well with the absorption frequencies of chlorophyll a, but makes it evident that there are some other contributors to the absorption.
The plot of the absorption spectra of the chlorophylls plus beta carotene. Photosynthesis is the process by which plants take carbon dioxide from the atmosphere, add water, and use the energy of sunlight to produce sugar.
Photosynthesis occurs in the chloroplast, an organelle in plant cells that contains the molecule chlorophyll. If the pH is too high or too low, the rate of photosynthesis will decrease.
If the pH is just right, the rate will increase to the best possible point. Photosynthesis is the process by which plants create their food. It involves the operation of enzymes in the plant cells, and they work best at certain pH levels.