Function of chloroplast

Chloroplast: Structure and Function Present in plants and certain algae, chloroplasts are a type of membrane-bound plastids. They harbor light-harvesting pigments including chlorophyll, and serve as the site for photosynthesis as well as some reactions of photorespiration. Read on this article to know more. Did You Know? Billions of years ago, a eukaryotic cell engulfed a cyanobacteria, which survived inside the cell, and later on evolved to become the chloroplast. Plants and certain algae are characterized by the unique ability of photosynthesis, the synthesis of food molecules in the presence of sunlight. This ability is conferred through the presence of specialized organelles called chloroplasts, commonly referred to as the ‘kitchens’ of plant cells. Chloroplasts are plastids that contain a network of membranes embedded into a liquid matrix, and harbor the photosynthetic pigment called chlorophyll. It is this pigment that imparts a green color to plant parts, and serves to capture light energy. A detailed account of the structure and functions of chloroplasts has been provided below. Chloroplasts are located in the parenchyma cells of plants as well as in autotrophic algae. They are oval-shaped organelles having a diameter of 2 – 10 µm and a thickness of 1 – 2 µm. Although their dimensions are almost similar in all plants, the algal chloroplasts show a variation in their size as well as shape. The major components of a chloroplast are as illustrated and explained below....

Learn about the structure of chloroplast and its role in photosynthesis Chloroplasts are a type of plastid—a round, oval, or disk-shaped body that is involved in the synthesis and storage of foodstuffs. Chloroplasts are distinguished from other types of plastids by their green colour, which results from the presence of two pigments, a and b. A function of those pigments is to absorb light energy for the process of Dissect a chloroplast and identify its stroma, thylakoids, and chlorophyll-packed grana Chloroplasts are roughly 1–2 μm (1 μm = 0.001 mm) thick and 5–7 μm in granum. The thylakoid membrane envelops a central aqueous region known as the thylakoid lumen. The space between the inner membrane and the thylakoid membrane is filled with The photosynthetic machinery The thylakoid membrane houses chlorophylls and different ATP and NADPH are used in the light-independent reactions (dark reactions) of photosynthesis, in which 4 plants, the initial carbon fixation step and the Calvin cycle are separated spatially—carbon fixation occurs via phosphoenolpyruvate (PEP) carboxylation in chloroplasts located in the mesophyll, while malate, the four-carbon product of that process, is transported to chloroplasts in bundle-sheath cells, where the Calvin cycle is carried out. C 4 photosynthesis attempts to minimize the loss of carbon dioxide to photorespiration. In plants that use crassulacean acid

• An outer and inner layers with anintermembrane spacebetween them. • Inside theinner membraneare ribosomesand thylakoids. • Theinner membranecontains an aqueous jelly called the stroma. • The stroma fluid contains thechloroplast DNAas well as proteins and starches. It is where the formation of carbohydrates from photosynthesis takes place. The Function of Chloroplast Ribosomes and Thylkaoids Light reactions only take place during the day when light energy strikes the plant while dark reactions can take place at any time. The light reactions start in the thylakoid membrane while the carbon fixing of the dark reactions takes place in the stroma, the jelly-like liquid surrounding the thylakoids. Bert Markgraf is a freelance writer with a strong science and engineering background. He has written for scientific publications such as the HVDC Newsletter and the Energy and Automation Journal. Online he has written extensively on science-related topics in math, physics, chemistry and biology and has been published on sites such as Digital Landing and Reference.com He holds a Bachelor of Science degree from McGill University.

The aqueous lumen enclosed by the thylakoid membrane network of the chloroplast is the compartment where molecular oxygen is produced from water during photosynthetic light-dependent reactions. The thylakoid lumen has been thought for a long time to contain mainly plastocyanin and oxygen-evolving complex-associated proteins, playing important roles during these reactions. In the last decade, the functional characterization of thylakoid lumenal proteins from Arabidopsis thaliana has brought insights into the complex role of this subcellular compartment. The aim of this chapter is to provide an updated view of the protein composition of the thylakoid lumen and its emerging roles in photosynthetic regulation and plant cell signaling. Recent research has uncovered redox signaling and a new paradigm about the role of nucleotides in the thylakoid lumen. Keywords • Thylakoid Membrane • PSII Activity • PSII Complex • Thylakoid Lumen • Photosynthetic Complex These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves. • Abdel-Ghany SE (2009) Contribution of plastocyanin isoforms to photosynthesis and copper homeostasis in Arabidopsis thaliana grown at different copper regimes. Planta 229:767–779 • Allahverdiyeva Y, Mamedov F, Holmström M, Nurmi M, Lundin B, Styring S, Spetea C, Aro EM (2009) Comparison of the electron transport properties of the psbo1 and psbo2 mutants of Arabidopsis th...

Most life on Earth depends on photosynthesis.The process is carried out by plants, algae, and some types of bacteria, which capture energy from sunlight to produce oxygen (O2) and chemical energy stored in glucose (a sugar). Herbivores then obtain this energy by eating plants, and carnivores obtain it by eating herbivores. The process During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil. Within the plant cell, the water is oxidized, meaning it loses electrons, while the carbon dioxide is reduced, meaning it gains electrons. This transforms the water into oxygen and the carbon dioxide into glucose. The plant then releases the oxygen back into the air, and stores energy within the glucose molecules. Chlorophyll Inside the plant cell are small organelles called chloroplasts, which store the energy of sunlight. Within the thylakoid membranes of the chloroplast is a light-absorbing pigment called chlorophyll, which is responsible for giving the plant its green color. During photosynthesis, chlorophyll absorbs energy from blue- and red-light waves, and reflects green-light waves, making the plant appear green. Light-dependent reactions vs. light-independent reactions While there are many steps behind the process of photosynthesis, it can be broken down into two major stages: light-dependent reactions and light-independent reactions. The light-dependent reaction takes place within the thylakoid membrane and requires a steady stream of s...

Image Many-fruited thyme-moss Chlorophyll is a key component in the process of photosynthesis, which sustains plant life and produces oxygen for the entire planet. Although microscopic in size, chloroplasts like these have a big role to play in the health of the planet. Photograph by Kristian Peters—Fabelfroh, licensed under CC BY-SA 3.0 Unported. Green plants have the ability to make their own food. They do this through a process called photosynthesis, which uses a green pigment called chlorophyll. A pigment is a molecule that has a particular color and can absorb light at different wavelengths, depending on the color. There are many different types of pigments in nature, but chlorophyll is unique in its ability to enable plants to absorb the energy they need to build tissues. Chlorophyll is located in a plant’s chloroplasts, which are tiny structures in a plant’s cells. This is where photosynthesis takes place. Phytoplankton, the microscopic floating plants that form the basis of the entire marine food web, contain chlorophyll, which is why high phytoplankton concentrations can make water look green. Chlorophyll’s job in a plant is to absorb light—usually sunlight. The energy absorbed from light is transferred to two kinds of energy-storing molecules. Through photosynthesis, the plant uses the stored energy to convert carbon dioxide (absorbed from the air) and water into glucose, a type of sugar. Plants use glucose together with nutrients taken from the soil to make new ...

Yan Lu 1, Lu-Ning Liu 2, Rebecca L. Roston 3, Jürgen Soll 4 and Hongbo Gao 5 * • 1Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, United States • 2Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom • 3Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, United States • 4Ludwig Maximilian University of Munich, Munich, Germany • 5College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China As the site of photosynthesis, the chloroplast is responsible for producing all the biomass in plants. It is also a metabolic center for production or modification of many important compounds, such as carbohydrates, purines, pyrimidines, amino acids, fatty acids, precursors of several plant hormones, and many secondary metabolites. The chloroplast also extensively communicates with other parts and organelles of the cell. We were fortunate enough to have submissions from ~100 talented chloroplast researchers. This topic contains 17 papers of which 11 are original research, 4 are reviews or mini-reviews, and one is a perspective. As the chloroplast is semi-autonomous, the biogenesis, development, division, and partitioning of chloroplasts rely on nuclear-encoded proteins as well. A nuclear-encoded chloroplast-localized translation elongation factor EF-Tu was found to be essential to chloroplast development in the flowering plant Arabidopsis thaliana ( A...

In …tight stacks called grana (singular granum). Grana are connected by stromal lamellae, extensions that run from one granum, through the stroma, into a neighbouring granum. The thylakoid membrane envelops a central aqueous region known as the thylakoid lumen. The space between the inner membrane and the thylakoid membrane is filled… role in photosynthesis • In …higher plants have regions, called grana, in which the thylakoids are very tightly stacked. When viewed by electron microscopy at an oblique angle, the grana appear as stacks of disks. When viewed in cross section, it is apparent that some thylakoids extend from one grana through the stroma into other… •