Question

[AP Bio] Light wavelength significance for photosynthesis?

I am writing an analysis based on a theoretical lab report made by other ''students,'' and for the lab they were going to experiment on 'the amount of light and the wavelength of light.' and its significance for photosynthesis. I wrote the theory part below but I am not sure if I should elaborate on anything in particular, or if something is redundant, irrelevant, etc.

I want the theory to be factual and relevant, that is, for it to explain the theories needed to explain and analyze the result in the discussion, also for it to include concepts and phenomena and explain them in-depth and correct way.. thoughts?

THEORY:

Most of the energy that hits our planet comes from the sun, and this is energy in the form of electromagnetic radiation over a large wavelength spectrum. The light that hits the earth is very important for photosynthesis. Leaf dyes such as chlorophyll and carotene capture energy from the light and absorb red and blue light as they have a great effect on photosynthesis. These dyes are called pigments and are found in photosynthetic organisms, these pigments being the light-absorbing molecules that absorb only specific wavelengths of light, while reflecting other wavelengths. Chlorophyll is a green pigment that is common to all photosynthetic cells, and reflects green light while absorbing other wavelengths, which explains why most of us can see a plant as green.

Generally, there are five major types of chlorophyll, chlorophyll a, b, c, d as well as a molecule found in prokaryotes and called bacterial chlorophyll. Chlorophyll a and b are the most important pigments for photosynthesis. Chlorophyll is found in algae and cyanobacteria, while chlorophyll b is found in green algae and plants. Chlorophyll is found in the thylakoids of the chloroplasts, which are surrounded by its own membrane, the lumen, and is in addition to the inner and outer membranes of the chloroplasts, the third membrane, and it is within the thylakoids that the photosynthetic light-dependent reaction takes place. The pigment molecules, together with proteins, are used to form a chemical structure called a photosystem. Each photosystem contains proteins and captures energy-rich photons through the chlorophyll contained in the photosystem. The energy is then used to break down water into oxygen, electron and hydrogen ion. The hydrogen ion concentration, in turn, becomes higher within the thylakoid membrane, or lumen in other words. Further, ATP synthase utilizes these hydrogen ions to produce ATP, which is later used in the non-light dependent reaction. ATP is the cell's energy source, but is rather short-lived in the cell and is therefore used to produce sugar.

By measuring how fast it is possible to absorb carbon dioxide, or how fast carbohydrates are formed, or how fast oxygen is released, we can determine the rate of photosynthesis. This speed is characterized by the brightness, as well as the availability of carbon dioxide. It can be noted that the change in photosynthesis rate is relative to wavelength, which can be obtained by measuring photosynthesis rate when illuminating a plant with the light of different wavelengths, but that they have the same energy content. Short-wave radiation, such as X-rays and ultraviolet light, contains more energy than long-wave radiation.

Theoretically, the light intensity should not be as effective in connection with the growing distance from which the lamp emits its light to the beaker. It is said that the light intensity has an inverse proportion to the square of the distance; thus, this is the inverse square law. Thus, it can be described as: I ∝ 1 / d2, where d stands for the distance in the unit meter, I stands for the light intensity with the unit W / m2, where W stands for watts or energy per second, and where ∝ stands for proportion.

Answer 1

Most of the energy that hits our planet comes from the sun, and this is energy in the form of electromagnetic radiation over a large wavelength spectrum.Plants capture light energy and using it to make sugars through a process called photosynthesis. This process begins with the absorption of light by specialized organic molecules, called pigments, that are found in the chloroplasts of plant cells.Chlorophyll is a green pigment that is common to all photosynthetic cells.The various wavelengths in sunlight are not all used equally in photosynthesis. The pigments  absorb only specific wavelengths of visible light, while reflecting others. Chlorophyll reflects green light while absorbing other wavelengths, which explains why most of us can see a plant as green.

Generally, there are five major types of chlorophyll, chlorophyll a, b, c, d as well as a molecule found in prokaryotes and called bacterial chlorophyll. Chlorophyll a and b are the most important pigments for photosynthesis. Chlorophyll is found in algae and cyanobacteria, while chlorophyll b is found in green algae and plants. Chlorophyll molecules are arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts.The pigment molecules, together with proteins, are used to form a chemical structure called a photosystem. Each photosystem contains proteins and captures energy-rich photons through the chlorophyll contained in the photosystem. The identity, function and spectral properties of the types of chlorophyll in each photosystem are distinct and determined by each other and the protein structure surrounding them. Although both chlorophyll a and chlorophyll b absorb light, chlorophyll a plays a unique and crucial role in converting light energy to chemical energy.Because of the central role of chlorophyll a in photosynthesis, all pigments used in addition to chlorophyll a are known as accessory pigments—including other chlorophylls, as well as other classes of pigments like the carotenoids. The use of accessory pigments allows a broader range of wavelengths to be absorbed, and thus, more energy to be captured from sunlight.The energy is then used to break down water into oxygen, electron and hydrogen ion. The hydrogen ion concentration, in turn, becomes higher within the thylakoid membrane, or lumen in other words. Further, ATP synthase utilizes these hydrogen ions to produce ATP, which is later used in the non-light dependent reaction. ATP is the cell's energy source, but is rather short-lived in the cell and is therefore used to produce sugar.

By measuring how fast it is possible to absorb carbon dioxide, or how fast carbohydrates are formed, or how fast oxygen is released, we can determine the rate of photosynthesis. This speed is characterized by the brightness, as well as the availability of carbon dioxide. It can be noted that the change in photosynthesis rate is relative to wavelength, which can be obtained by measuring photosynthesis rate when illuminating a plant with the light of different wavelengths, but that they have the same energy content. Short-wave radiation, such as X-rays and ultraviolet light, contains more energy than long-wave radiation. Certain red and blue wavelengths of light are the most effective in photosynthesis because they have exactly the right amount of energy to energize, or excite, chlorophyll electrons and boost them out of their orbits to a higher energy level.

The figure given below shows the electromagnectic spectrum

The figure given below shows the activity of pigments in different wave length of light.

Theoretically, the light intensity should not be as effective in connection with the growing distance from which the lamp emits its light to the beaker. It is said that the light intensity has an inverse proportion to the square of the distance; thus, this is the inverse square law. Thus, it can be described as: I ∝ 1 / d2, where d stands for the distance in the unit meter, I stands for the light intensity with the unit W / m2, where W stands for watts or energy per second, and where ∝ stands for proportion.