Light dependent reactions of photosynthesis

Student Answers jerveelim Student Photosynthesis converts the light energy from the sun into chemical energy that is useful for the plants.

Light dependent reactions of photosynthesis

How is ATP produced in cells; what is the difference between the energy-producing process in animal cells and plant cells? How much ATP is produced?

You have asked a classic question in biology, and of course, a very important one. How living things produce usable energy is important not only from the perspective of understanding life, but it could also help us to design more efficient energy harvesting and producing products - if we could "mimic" how living cells deal with their energy balance, we might be able to vastly improve our technology.

For example, a plant is a much better harvester of sunlight than even our best solar panel. And of course, if we understand energy use, it can also help us deal with human diseases such as diabetes. Now, the answer to your question can be found in any basic biology text book, but sometimes, there is so much information packed into such a text book that it can be difficult to extract the information you need or more often, to view all of that information in a larger context.

Let's try to tackle your question in several parts. First, we need to know what ATP really is - chemically, it is known as adenosine triphosphate. ATP is a usable form of energy for cells - the energy is "trapped" in a chemical bond that can be released and used to drive other reactions that require energy endergonic reactions.

Photosynthetic organisms use energy from sunlight to synthesize their own fuels. They can convert harvested sunlight into chemical energy including ATP to then drive the synthesis of carbohydrates from carbon dioxide and water.

When they synthesize the carbohydrates, oxygen gets released. Globally, more than 10 billion tons of carbon is "fixed" by plants every year - this means that carbon molecules are converted from being part of a simple gas carbon dioxide into more complex, reduced molecules carbohydratesmaking carbon available as food for non-photosynthesizers and of course, providing oxygen.

They use some of the carbohydrate for their own growth and reproduction. It is pretty remarkable when you think about it - have you been to Sequoia National Park or seen the redwoods along our northwest coast?

Think about the fact that most of that mass is in the form of carbon that was pulled out of the air as carbon dioxide!

The process of photosynthesis is two-part. First, there are the light reactions, where light is converted into chemical energy a reduced electron carrier and ATP. This occurs in the thylakoids stacked membranes of the chloroplasts. The ATP and electron carriers are then used in a second set of reactions, called the light-independent reactions.

This also occurs in the chloroplasts, but in an area called the stroma. In this case, carbon dioxide gets used to produce sugars in a series of reactions called the Calvin Cycle, C4 photosynthesis, and crassulacean acid metabolism. You can look in any basic bio textbook to see how much "energy" or "sugar" is produced in each step of the process.

In non-photosynthesizers, the fuel has to be consumed.

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The most common chemical fuel is the sugar glucose C6H12O Other molecules, such as fats or proteins, can also supply energy, but usually they have to first be converted to glucose or some intermediate that can be used in glucose metabolism.

Now this brings us to the next part - how do we go from glucose to ATP? This is achieved through the process of "oxidation" - and this is carried out through a series of metabolic pathways.

Complex chemical transformations in the cell occur in a series of separate reactions to form each pathway, and each reaction is catalyzed by a specific enzyme. Interestingly, metabolic pathways are similar in all organisms, from bacteria to humans. In eukaryotes plants and animals many of the metabolic pathways are compartmentalized, with certain reactions occurring in specific organelles.

Basically, cells trap free energy released from the breakdown metabolism of glucose. There are 3 main pathways for harvesting energy from glucose:These videos cover the new GCSE specification which is first examined in These videos apply to all the exam boards.

See also:Calvin cycle In the light-dependent reaction, light energy from the sun is used to split water (). which has been taken in by, when broken, makes oxygen, hydrogen, and electrons move through structures in chloroplasts and by chemiosmosis, make ATP..

The hydrogen is converted to NADPH which is then used in the light-independent reactions. There's a lot of carbon in your body - in DNA, proteins, carbohydrates, fats, and other key biological molecules. How did that carbon get there? Drumroll photosynthesis! Learn how plants and other photosynthetic organisms use light energy to make sugars from carbon dioxide and water, bringing both chemical energy and readily usable carbon into Earth’s global ecosystem.

The process of photosynthesis is commonly written as: 6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O means that the reactants, six carbon dioxide molecules and six water molecules, are converted by light energy captured by chlorophyll (implied by the arrow) into a sugar molecule and six oxygen molecules, the products.

The sugar is used by the organism, and the oxygen is released as a by-product. 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.

This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις.

Light dependent reactions of photosynthesis

Photosynthesis converts the light energy from the sun into chemical energy that is useful for the plants. There are two photosystems acting in series within the thylakoid membranes of the.

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