1) What Are Action and Absorption Spectra? How Is the Absorption Spectrum for Chlorophyll Different from the Action Spectrum for Photosynthesis? Why?

Good Essays
Electromagnetic energy, in the form of light, travels in wavelengths and is measured in nanometres (nm). Pigments within matter, such as plants, absorb varying wavelengths of light. The absorption spectrum can be defined as a graphical representation of a pigment’s ability to absorb light against varying wavelengths (nm). The pigments light absorbing ability is measured using a spectrophotometer.
An action spectrum can be defined as the graphical representation of the rate of photosynthesis against wavelengths of light. The graph shows how effective the different wavelengths of light are at enabling photosynthesis, and this can be determined by measuring either the carbon dioxide consumed or by the amount of oxygen released.
Chlorophyll is a pigment found in the chloroplasts of organisms. In plants, it is the chlorophyll that absorbs the light energy and drives photosynthesis. On the absorption spectrum, chlorophyll a and b seem to be effective within the violet to blue (approximately 400 – 500nm) region and the red region. This indicates that these types of light are most effectively absorbed by the chlorophyll and it is suggested that these types of lights work best in photosynthesis. The absorption spectrum shows that green is the least effectively absorbed. In comparison, the action spectrum for photosynthesis does not match the absorption spectrum. The action spectrum suggests that a greater range of wavelengths are able to facilitate photosynthesis. This is because it does not exclusively take into account the contribution of chlorophyll a and b in photosynthesis. The action spectrum also takes into account the work of the accessory pigments in the plant, which absorb other types of light from a greater range of wavelengths, and therefore assist in driving

You May Also Find These Documents Helpful

  • Powerful Essays

    Absorption Spectra

    • 957 Words
    • 4 Pages

    Introduction At any particular wavelength the absorption of light when visible light passes through a solution depends on two factors: * The length of the light path * The concentration of the colored path The connection of these two variables is known as the Beer-Lambert Law: Absorbance (A) = ε c l Where ε is the absorption coefficient C is the concentration of the compound And l is the length of light usually 1cm When I is constant, this proves a linear relationship between…

    • 957 Words
    • 4 Pages
    Powerful Essays
  • Satisfactory Essays

    The Absorption Spectrum of Cobalt(II) Chloride Thang Dinh Lab partner: Alex Yang CHM 151 – 102 11/17/2014 Introduction: Many compounds absorb a certain spectrum of visible light. Since Beer’s Law describe the relationship between molar absorptivity and concentration, one could use his equation A = kc to find the unknown concentration by the known absorptivity. The graph of absorption spectrum is represented by a linear regression. From the graph, one could deduct that as the concentration decreases…

    • 456 Words
    • 4 Pages
    Satisfactory Essays
  • Powerful Essays

    Practical 3 ABSORPTION SPECTRA AND THE BEER-LAMBERT LAW The purpose of this practical was to measure the amount of a chemical substance present in a sample. Primarily, the aim of Experiment 1 was to measure the absorption spectrum of a particular coloured substance (in this case Bromophenol Blue and Methyl Orange) at varying wavelengths of light. For Experiment 2, the process of the experiment focuses on the substance and records its absorption levels at different concentrations. The absorption levels…

    • 959 Words
    • 4 Pages
    Powerful Essays
  • Better Essays

    Photosynthesis Matt Lazar 5/13/96 8th Hr. When you and me eat, we find our food. When plants eat, they make their own food and energy. They make their food and energy through a process called photosynthesis. Through photosynthesis oxygen is also produced. Photosynthesis is "a process in which green plants synthesize carbohydrates from carbon dioxide and water....The reverse of this reaction provides energy for plants, for animals that eat plants, for animals that eat animals that eat plants"…

    • 778 Words
    • 4 Pages
    Better Essays
  • Good Essays

    Introduction: Experiments 1 and 2 main aims are as follows: • To able to use the Beer-Lambert law to explain the relationship linking concentration and absorbance of the coloured solutions methyl orange and bromophenol blue. • To be able to rightly operate a spectrophotometer to assess the absorbance at various wavelengths • To be able to identify the main component parts of a spectrophotometer • To be able to draw a ‘Standard Curve’ from the data collected •…

    • 611 Words
    • 3 Pages
    Good Essays
  • Better Essays

    Practical 3 Absorption Spectra and the Beer-Lambert Law INTRODUCTION Electromagnetic radiation can be described in terms of frequency (V) and wavelength (λ). Absorbance is the capacity of a substance to absorb radiation and transmittance (the fraction radiation at a specified wavelength that passes through a sample) is physical properties that all molecules have. The purpose of experiment one was to find the maximum absorbance (λmax) occurred for both bromophenol blue and methyl orange by…

    • 1007 Words
    • 5 Pages
    Better Essays
  • Powerful Essays

    Gas Absorption

    • 3547 Words
    • 19 Pages

    fires high sulfur eastern bituminous coal producing SO2 loadings up to 7.5 lbs/MBtu. To increase the removal in the WFGD system, MSCPA and B&W added a second tray in 2002 to take advantage of dual tray technology. SO2 removal has been increased from 90% to 98% without the use of organic acids. Performance tests and parametric tests have been performed on the system over the last two years. The testing also included tests for SO3, HF, HCl, and PM. This paper discusses the absorber design, operating…

    • 3547 Words
    • 19 Pages
    Powerful Essays
  • Good Essays

    Absorption of different cloth diapers Problem The purpose of this experiment is to determine which type of cloth diaper can absorb the most amount of water before coming out in any way (either through the diaper or out the sides). Relevance There are many types of cloth diapers on the market these days. They are very expensive and I believe that most parents would like to buy a cloth diaper that has the most absorption. No one wants to put any diaper on their child that will leak through…

    • 1074 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Digestion & Absorption

    • 1179 Words
    • 5 Pages

    release starch –digesting (amylase) enzymes, initiate swallowing reflex - Enzyme: alpha amylase with cooked starch as substrate – starch digestion enzyme an enzyme that catalyses the breakdown of starch into sugar - The Functions of Saliva - 1. Moistens and lubricates food, permitting swallowing 2. Holds taste producing substances in solution and bring them in contact w/ taste buds 3. Dilutes acids and salts, protecting mucosa and teeth 4. Cleansing effect on teeth, gums and buccal mucosa…

    • 1179 Words
    • 5 Pages
    Good Essays
  • Good Essays

    Atomic Absorption

    • 5711 Words
    • 23 Pages

    steps , one is atomization of sample and the other is absorption of light radiation from light source. The atoms in the vapour are measured by absorption or emission at characteristic wave lengths. The main usage of this was to detect one element from another in the complex sample which has taken ie., it has ability to perform multiple element analyses. Absorbance should obey Beer’s law ie., Analyte is measured in diluted concentrations from parts per million level to parts per trillion level and…

    • 5711 Words
    • 23 Pages
    Good Essays