Chromosomes 3. Meiosis 4. Inheritance 5. Genetic Modification 4: Ecology 1. Energy Flow 3. Carbon Cycling 4. Climate Change 5: Evolution 1. Evolution Evidence 2. Natural Selection 3. Classification 4. Cladistics 6: Human Physiology 1. Digestion 2.
The Blood System 3. In the case of photosynthesis, light energy is transformed into chemical energy, which autotrophs use to build carbohydrate molecules. However, autotrophs only use a specific component of sunlight Figure 1. Figure 1. Autotrophs can capture light energy from the sun, converting it into chemical energy used to build food molecules.
Fish and Wildlife Service. Visit this site and click through the animation to view the process of photosynthesis within a leaf. Figure 2. The wavelength of a single wave is the distance between two consecutive points along the wave. The sun emits an enormous amount of electromagnetic radiation solar energy. Scientists can determine the amount of energy of a wave by measuring its wavelength, the distance between two consecutive, similar points in a series of waves, such as from crest to crest or trough to trough Figure 2.
Visible light constitutes only one of many types of electromagnetic radiation emitted from the sun. The electromagnetic spectrum is the range of all possible wavelengths of radiation Figure 3. Each wavelength corresponds to a different amount of energy carried.
Figure 3. The sun emits energy in the form of electromagnetic radiation. This radiation exists in different wavelengths, each of which has its own characteristic energy. Visible light is one type of energy emitted from the sun. Each type of electromagnetic radiation has a characteristic range of wavelengths. The longer the wavelength or the more stretched out it appears , the less energy is carried.
Short, tight waves carry the most energy. This may seem illogical, but think of it in terms of a piece of moving rope. It takes little effort by a person to move a rope in long, wide waves. To make a rope move in short, tight waves, a person would need to apply significantly more energy.
The sun emits Figure 3 a broad range of electromagnetic radiation, including X-rays and ultraviolet UV rays. The higher-energy waves are dangerous to living things; for example, X-rays and UV rays can be harmful to humans. Light energy enters the process of photosynthesis when pigments absorb the light. This is the part of photosynthesis that requires the CO 2 the plant gets from the air.
Essentially, the plant needs the carbon from the CO 2 to create the building blocks for glucose. An enzyme in the stroma called ruBisCo combines a five-carbon molecule of RubP ribulose biphosphate with a molecule of carbon dioxide. This creates a six-carbon molecule that is broken down into two three-carbon molecules 3-phosphoglycerate. This part of the light-independent reactions is referred to as carbon fixation. Then, the energy carriers from the light-dependent reactions make their contribution.
Ultimately, these two molecules of G3P are used to build one molecule of glucose. This part of the light-independent reactions is typically referred to as reduction or reducing the sugar because electrons are added. It is important to note that the Calvin cycle typically uses six molecules of carbon dioxide at a time.
This means that twelve molecules of G3P are generated. However, only two of them are used to produce a molecule of glucose—the rest are recycled back into RubP so that the cycle can keep running. See more from our free eBook library. Article from Scitable that details the internal structure of chloroplasts. Just as the name implies, light-dependent reactions require sunlight. In the light-dependent reactions, energy from sunlight is absorbed by chlorophyll and converted into stored chemical energy, in the form of the electron carrier molecule NADPH nicotinamide adenine dinucleotide phosphate and the energy currency molecule ATP adenosine triphosphate.
The light-dependent reactions take place in the thylakoid membranes in the granum stack of thylakoids , within the chloroplast. The process that converts light energy into chemical energy takes place in a multi-protein complex called a photosystem. Each photosystem plays a key role in capturing the energy from sunlight by exciting electrons. Photosystems consist of a light-harvesting complex and a reaction center.
Pigments in the light-harvesting complex pass light energy to two special chlorophyll a molecules in the reaction center.
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