Chloroplasts In Biology

Light intensity is a key component in photosynthesis, amongst carbon dioxide and water to sustain a suitable rate of photosynthesis. Chlorophyll absorbs the light, causing photoexcitation and the formation of NADPH and ATP with production of O2 as a by-product. The Calvin Cycle takes the NADPH and ATP to reduce CO2 into sugars (CH2O), and return NADP+ and ADP + Pi to the light reactions. The process will then repeat. (Reece, et al, 2015)

The light reactions also generate ATP by using chemiosmosis through a process called photosphorylation. The light energy is converted into chemical energy in the form of two compounds, which are NADPH and ATP. The Calvin cycle occurs with the incorporation of carbon dioxide into organic molecules in carbon fixation. In this process, the fixed carbon is reduced with electrons provided by NADPH. The Calvin cycle takes place during daylight hours, in which the NADPH and ATP can be provided. The Calvin cycle occurs in the stroma, while the light reactions occur in the thylakoids.

There are two main types of chlorophyll, chlorophyll a which absorbs wavelengths of 430nm (blue) and 662 (red) and is the main photosynthetic pigment, and chlorophyll b, which doesn’t directly participate in the photosynthetic process, but is capable of donating its energy to chlorophyll a

Photosynthesis occurs each time the sun’s light reaches the lives of a plant. The chemical ingrediants for photosynthesis are carbon dioxide (CO2), a gas that passes from the air into a plant via tiny pores, and water (H20), which absorbed from the soil by the plant’s roots. Inside leaf cells, tiny structures called chloroplasts use light energy to rearrange the atoms of the ingrediants to produce sugars, most importantly glucose (C6H12O6) and other organic molecules. Chlorophyll gives the plant its green color (Simon, 02/2012, pp. 92-93). Chemical reactions transfers the sun’s light energy into the chemical bonds that hold energy-carrying molecules. The most common are

L. Relate the functions of the antenna complex and the reaction center in a chloroplast

In photosynthesis H+ ions are vital in the production of the energy source that is ATP, which is used in several metabolic processes, such as respiration. The photolysis of water produces H+ ions, electrons and O2. The excited electrons lose energy as they move along the electron transport chain, this energy is used to transport the H+ ions (protons) in to the thylakoid, which causes a higher concentration of H+ than there is in the stroma, thus causing a proton gradient across the membrane. The H+ then proceed to move down the concentration gradient into the stroma via the enzyme ATP synthase. The energy from this process is called chemiosmosis and combines ADP with inorganic phosphate (Pi) to form ATP. Light energy is then absorbed by photosystem I (PS I) which excites the electrons to a higher energy level. These electrons are transferred to NADP with H+ ions from the stroma to form reduced NADP. The whole of this process is

82. Oxidation occurs when there is a removal of electrons and/or hydrogen atoms from a

University Press, Cambridge, United Kingdom. E J H Corner, 2002. The Life of Plants. University of Chicago Press,

During Photosynthesis: In light-dependent reactions the ATP and NADPH molecules produced convert CO2 into carbohydrate molecules like glucose. In light-independent reactions use the chemical energy and CO2 to create long-term energy storage molecules like carbohydrates such as glucose. This process uses six molecules of carbon dioxide to make just one six-carbon glucose molecule. The three-carbon molecules are broken down, this removes some of the atoms attatched to the carbons and ATP and NADPH are used, resulting in a three-carbon chain with different atoms in the molecule.

Intro outline Chloroplast function Its movements: photorelocation Importance of chloroplast location Proteins involved with it Correlation with light How the light induces the protein In plants, chloroplasts function to conduct photosynthesis where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water. They then use the ATP and NADPH to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, much amino acid synthesis, and the immune response in plants.

The role of the hydrogen ion gradients in both cellular respiration in the mitochondria and photosynthesis in the chloroplast is that the hydrogen gradients is the gradient stores the energy. Chemiosmosis is the movement of ions across the membrane. Chemiosmosis generate ATP by the movement of hydrogen ions across the membrane during cellular respiration and photosynthesis. In the cellular respiration it travels down the electron transport system and in photosynthesis it travels through the ATP synthases. Both the cellular respiration and the photosynthesis uses ATP energy to temporarily use the energy it stores for future uses. Photosynthesis uses solar energy to convert into the chemical bond of glucose and cellular respiration converts the

Life on Earth is dependent entirely on the energy from the Sun, not only to keep the planet at a suitable temperature but also to provide the energy required to sustain life. The energy of the Sun, in the form of photons, is actively captured by chlorophyll and related pigments present in photosynthetic organisms, like plants and algae. This captured energy is used to convert carbon dioxide into complex energy-rich molecules that can be used by themselves

     Photosynthesis has a two-stage performance before plants produce the two products they are known to produce. These stages are Photosystem I and II. Photosystem II is dependant on light reactions for energy which causes the electrons to be react and be transferred to Photosystem II. The electrons are transported through the Photosystem II electron transport system, however some energy is used to drive ATP synthesis. Meanwhile, light is being absorbed by the Photosystem I, which causes the electrons to react. This process sends the electrons to the Photosystem I transport system where some energy is released as electrons travel through the electron transport system and is captured as NADPH. When this process is completed oxygen is released from the plant and glucose has been

     To metabolic pathways involved in photosynthesis are light reaction and dark reaction. The first stage of the photosynthetic system is the light-dependent reaction, which converts solar energy into chemical energy. Light absorbed by chlorophyll or other photosynthetic pigments is used to drive a transfer of electrons and hydrogen from water to and acceptor called NADP , reducing it to the form of NADPH by adding a pair of electrons and a single proton. The water or some other donor molecule is split in the process. The light reaction also generates ADP, a process called photophosphorylation. ATP is a versatile source of chemical energy used in most biological processes. The light reaction produces no carbohydrates such as sugars.

Photosynthesis is a very complicated process. It is not as simple as plants need a little sunlight, water, and carbon dioxide, and viola oxygen is produced. There are many steps and processes that occur during photosynthesis which make it very complicated. Now the actual word photosynthesis in Greek means photo- “light”, and –synthesis “putting together”. This is the overall basic foundation that photosynthesis stands behind. Photosynthesis can only happen in plants and some algae, due to them having an organelle called chloroplast. Chloroplast has a pigment, which is called chlorophyll. Chlorophyll is a light absorbing pigment, which allows the plant to control solar energy and use it to distribute energy and food for the plant itself. Chloroplasts are usually located in the green tissue in the interior of the leaf called the mesophyll. A usual cell has around thirty to forty chloroplast. In the inner compartment there is a thick fluid called the stroma, with a system of interconnected membranous