The photosythesis

Ultimately, light energy must be transferred to a pigment-protein complex that can convert it to chemical energy, in the form of electrons. A typical plant cell contains about 10 to chloroplasts. The green part of the light spectrum is not absorbed but is reflected which is the reason that most plants have a green color.

Most of the removed electrons and hydrogen ions ultimately are transferred to carbon dioxide CO2which is reduced to organic products.

What Is Photosynthesis?

Cross section of a leaf, showing the anatomical features important to the study of photosynthesis: C-4 plants, which often grow close together, have had to adjust to decreased levels of carbon dioxide by artificially raising the carbon dioxide concentration in certain cells to prevent photorespiration.

Absorption and transmission of different wavelengths of light by a hypothetical pigment. The cells in the interior tissues of a leaf, called the mesophyllcan contain betweenandchloroplasts for every square millimeter of leaf.

This pigment is mainly seen in purple and green bacteria, which perform anoxygenic photosynthesis. The electron from Photosystem II replaces the excited electron in the P molecule.

These pigments are embedded in plants and algae in complexes called antenna proteins. Both "active" forms of chlorophyll a function in photosynthesis due The photosythesis their association with proteins in the The photosythesis membrane.

Oh yes, we need the food as well! Only eukaryotes have chloroplasts with a surrounding membrane. This electron is passed to a modified form of chlorophyll called pheophytinwhich passes the electron to a quinone molecule, starting the flow of electrons down an electron transport chain that leads to the ultimate reduction of NADP to NADPH.

The conversion to chemical energy is accomplished when a chlorophyll pigment expels an electron, which can then move on to an appropriate recipient. The product of that reaction forms glycolic acid, a chemical that can be broken down by photorespiration, producing neither NADH nor ATP, in effect dismantling the Calvin Cycle.

The Light Reactions occur in the grana and the Dark Reactions take place in the stroma of the chloroplasts. Halobacteria, which grow in extremely salty water, are facultative aerobes, they can grow when oxygen is absent.

These red, orange, or yellow-colored pigments absorb bluish-green light. The antenna system is at the core of the chlorophyll molecule of the photosystem II reaction center.

Almost half a century passed before the concept of chemical energy had developed sufficiently to permit the discovery in that light energy from the sun is stored as chemical energy in products formed during photosynthesis.

CAM plants have a different leaf anatomy from C3 plants, and fix the CO2 at night, when their stomata are open. Describe how the pigments found on thylakoid membranes are organized into photosystems and how they relate to photon light energy.It would be impossible to overestimate the importance of photosynthesis in the maintenance of life on Earth.

If photosynthesis ceased, there would soon be little food or other organic matter on Earth. Most organisms would disappear, and in time Earth’s atmosphere would become nearly devoid of.


Photosynthesis consists of two stages, the light reactions and the dark reactions. The light reactions convert light into energy (ATP and NADHP) and the dark reactions use the energy and carbon dioxide to.

Stages of Photosynthesis | Back to Top Photosynthesis is a two stage process.

The first process is the Light Dependent Process (Light Reactions), requires the direct energy of light to make energy carrier molecules that are used in the second process. Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities (energy transformation).

Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight into chemical energy. There are two types of photosynthetic processes: oxygenic photosynthesis and anoxygenic photosynthesis.

Oxygenic photosynthesis is the most common and is seen in plants, algae and cyanobacteria.

The photosythesis
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