Photosynthesis is a process used by plants and other organisms to convert light energyinto 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, synthesis, "putting together".[1][2][3] In most cases, oxygen is also released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies all of the organic compounds and most of the energy necessary for life on Earth.[4]
Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centresthat contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting of water is used in the creation of two further compounds that serve as short-term stores of energy, enabling its transfer to drive other reactions: these compounds are reduced nicotinamide adenine dinucleotide phosphate(NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells.
In plants, algae and cyanobacteria, long-term energy storage in the form of sugars is produced by a subsequent sequence of light-independent reactions called the Calvin cycle; some bacteria use different mechanisms, such as the reverse Krebs cycle, to achieve the same end. In the Calvin cycle, atmospheric carbon dioxide is incorporatedinto already existing organic carbon compounds, such as ribulose bisphosphate(RuBP).[5] Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reducedand removed to form further carbohydrates, such as glucose.
A. decreasing the speed at which filtrate flows through the nephron, leading to increased re-absorption of water.
Explanation:
Antidiuretic hormone (ADH) functions at the cellular level by decreasing the speed at which filtrate flows through the nephron, leading to increased reabsorption of water. This helps during dehydration.
Explanation: An ecological succession can be defined as a change that occur in the biotic community of the ecosystem with respect to the changes that occur in the abiotic factors like water, soil and climatic conditions with respect to time.
Secondary succession can be defined as the changes that occur in an area which was previously occupied by the living species and the area was disturbed by either human intervention or natural calamity.
Brazil clear cut is an example of secondary succession because after the clear cut some precursors like seeds, roots and other parts of the plants or trees can support the regrowth of plants and trees. Initiating the succession again.
Cell membranes are composed primarily of fatty-acid-based lipids and proteins. Membrane lipids are principally of two types, phospholipids and sterols (generally cholesterol).
