Lignin in the context of Natural phenol

Wood is a structural tissue/material found as xylem in the stems and roots of trees and other woody plants. Being a natural material, it is characterized as an organic material – a natural composite of cellulosic fibers that are strong in tension and embedded in a matrix of lignin and hemicelluloses that resists compression.

Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree, it performs a mechanical-support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients among the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fibers.

Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Any biomass rich in cellulose, hemicelluloses, and lignin are commonly referred to as lignocellulosic biomass. Each component has a distinct chemical behavior. Being a composite of three very different components makes the processing of lignocellulose challenging. The evolved resistance to degradation or even separation is referred to as recalcitrance. Overcoming this recalcitrance to produce useful, high value products requires a combination of heat, chemicals, enzymes, and microorganisms. These carbohydrate-containing polymers contain different sugar monomers (six and five carbon sugars) and they are covalently bound to lignin.

Lignocellulosic biomass can be broadly classified as virgin biomass, waste biomass, and energy crops. Virgin biomass includes plants. Waste biomass is produced as a low value byproduct of various industrial sectors such as agriculture (corn stover, sugarcane bagasse, straw etc.) and forestry (saw mill and paper mill discards). Energy crops are crops with a high yield of lignocellulosic biomass produced as a raw material for the production of second-generation biofuel; examples include switchgrass (Panicum virgatum) and elephant grass. The biofuels generated from these energy crops are sources of sustainable energy.

Organic matter, organic material or natural organic matter is the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have come from the feces and remains of organisms such as plants and animals. Organic molecules can also be made by chemical reactions that do not involve life. Basic structures are created from cellulose, tannin, cutin, and lignin, along with other various proteins, lipids, and carbohydrates. Organic matter is very important in the movement of nutrients in the environment and plays a role in water retention on the surface of the planet.

Vascular plants (from Latin vasculum 'duct'), also called tracheophytes (UK: /ˈtrækiːəˌfaɪts/, US: /ˈtreɪkiːəˌfaɪts/) or collectively Tracheophyta (/ˌtreɪkiːˈɒfɪtə/; from Ancient Greek τραχεῖα ἀρτηρία (trakheîa artēría) 'windpipe' and φυτά (phutá) 'plants'), are plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. The group includes most land plants (c. 300,000 accepted known species) excluding mosses.

Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers), and angiosperms (flowering plants). They are contrasted with nonvascular plants such as mosses and green algae. Scientific names for the vascular plants group include Tracheophyta, Tracheobionta and Equisetopsida sensu lato. Some early land plants (the rhyniophytes) had less developed vascular tissue; the term eutracheophyte has been used for all other vascular plants, including all living ones.

A corncob, also called corn cob or cob of corn, is the hard core of an ear of maize, bearing the kernels, made up of the chaff, woody ring, and pith. Corncobs contain mainly cellulose, hemicellulose, and lignin.

The cob is not toxic to humans and can be digested, but the outside is rough and practically inedible in its original form. The foamy pith has a peculiar texture when mature and is completely bland, which most people would find unappealing, due to the consistency similar to foam plastic.

Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The polynucleotides, RNA and DNA, are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids; some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate. Other examples of biopolymers include natural rubbers (polymers of isoprene), suberin and lignin (complex polyphenolic polymers), cutin and cutan (complex polymers of long-chain fatty acids), melanin, and polyhydroxyalkanoates (PHAs).

In addition to their many essential roles in living organisms, biopolymers have applications in many fields including the food industry, manufacturing, packaging, and biomedical engineering.

A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat non-vascular autotrophs such as mosses, algae and lichens, but do not include those feeding on decomposed plant matters (i.e. detritivores) or macrofungi (i.e. fungivores).

As a result of their plant-based diet, herbivorous animals typically have mouth structures (jaws or mouthparts) well adapted to mechanically break down plant materials, and their digestive systems have special enzymes (e.g. amylase and cellulase) to digest polysaccharides. Grazing herbivores such as horses and cattles have wide flat-crowned teeth that are better adapted for grinding grass, tree bark and other tougher lignin-containing materials, and many of them evolved rumination or cecotropic behaviors to better extract nutrients from plants. A large percentage of herbivores also have mutualistic gut flora made up of bacteria and protozoans that help to degrade the cellulose in plants, whose heavily cross-linking polymer structure makes it far more difficult to digest than the protein- and fat-rich animal tissues that carnivores eat.

Petrified wood (from Ancient Greek πέτρα meaning 'rock' or 'stone'; literally 'wood turned into stone'), is the name given to a special type of fossilized wood, the fossilized remains of terrestrial vegetation. Petrifaction is the result of a tree or tree-like plants having been replaced by stone via a mineralization process that often includes permineralization and replacement. The organic materials making up cell walls have been replicated with minerals (mostly silica in the form of opal, chalcedony, or quartz). In some instances, the original structure of the stem tissue may be partially retained. Unlike other plant fossils, which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material.

The petrifaction process occurs underground, when wood becomes buried in water or volcanic ash. The presence of water reduces the availability of oxygen which inhibits aerobic decomposition by bacteria and fungi. Mineral-laden water flowing through the sediments may lead to permineralization, which occurs when minerals precipitate out of solution filling the interiors of cells and other empty spaces. During replacement, the plant's cell walls act as a template for mineralization. There needs to be a balance between the decay of cellulose and lignin and mineral templating for cellular detail to be preserved with fidelity. Most of the organic matter often decomposes, however some of the lignin may remain. Silica in the form of opal-A, can encrust and permeate wood relatively quickly in hot spring environments. However, petrified wood is most commonly associated with trees that were buried in fine grained sediments of deltas and floodplains or volcanic lahars and ash beds. A forest where such material has petrified becomes known as a petrified forest.

In mammals, invertebrates and most fish, the anus (pl.: anuses or ani; from Latin, 'ring' or 'circle') is the external body orifice at the exit end of the digestive tract (bowel), i.e. the opposite end from the mouth. Its function is to facilitate the expulsion of waste that remains after digestion.

Bowel contents that pass through the anus include the gaseous flatus and the semi-solid feces, which (depending on the type of animal) include: indigestible matter such as bones, hair pellets, endozoochorous seeds and digestive rocks; residual food material after the digestible nutrients have been extracted, for example cellulose or lignin; ingested matter which would be toxic if it remained in the digestive tract; excreted metabolites like bilirubin-containing bile; and dead mucosal epithelia or excess gut bacteria and other endosymbionts. Passage of feces through the anus is typically controlled by muscular sphincters, and failure to stop unwanted passages results in fecal incontinence.

A cell wall is a structural layer that surrounds some cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, and functions as a selective barrier. Another vital role of the cell wall is to help the cell withstand osmotic pressure and mechanical stress. While absent in many eukaryotes, including animals, cell walls are prevalent in other organisms such as fungi, algae and plants, and are commonly found in most prokaryotes, with the exception of mollicute bacteria.

The composition of cell walls varies across taxonomic groups, species, cell type, and the cell cycle. In land plants, the primary cell wall comprises polysaccharides like cellulose, hemicelluloses, and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae exhibit cell walls composed of glycoproteins and polysaccharides, such as carrageenan and agar, distinct from those in land plants. Bacterial cell walls contain peptidoglycan, while archaeal cell walls vary in composition, potentially consisting of glycoprotein S-layers, pseudopeptidoglycan, or polysaccharides. Fungi possess cell walls constructed from the polymer chitin, specifically N-acetylglucosamine. Diatoms have a unique cell wall composed of biogenic silica.

Sea foam, ocean foam, beach foam, or spume is a type of foam created by the agitation of seawater, particularly when it contains higher concentrations of dissolved organic matter (including proteins, lignins, and lipids) derived from sources such as the offshore breakdown of algal blooms. These compounds can act as surfactants or foaming agents. As the seawater is churned by breaking waves in the surf zone adjacent to the shore, the surfactants under these turbulent conditions trap air, forming persistent bubbles that stick to each other through surface tension.

Sea foam is a global phenomenon, and it varies depending on location and the potential influence of the surrounding marine, freshwater, and/or terrestrial environments. Due to its low density and persistence, foam can be blown by strong on-shore winds inland, towards the beach. Human activities, such as production, transport or spillage of petroleum products or detergents, can also contribute to the formation of sea foam.

A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods (kraft and sulfite processes). The finished product may be either bleached or non-bleached, depending on the customer requirements.

Wood and other plant materials used to make pulp contain three main components (apart from water): cellulose fibres (desired for papermaking), lignin (a three-dimensional polymer that binds the cellulose fibres together) and hemicelluloses, (shorter branched carbohydrate polymers). The aim of pulping is to break down the bulk structure of the fiber source, be it chips, stems or other plant parts, into the constituent fibers.

Dietary fiber, fibre, or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition and can be grouped generally by their solubility, viscosity and fermentability which affect how fibers are processed in the body. Dietary fiber has two main subtypes: soluble fiber and insoluble fiber which are components of plant-based foods such as legumes, whole grains, cereals, vegetables, fruits, and nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases. Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulins, lignins, chitins, pectins, beta-glucans, and oligosaccharides.

Food sources of dietary fiber have traditionally been divided according to whether they provide soluble or insoluble fiber. Plant foods contain both types of fiber in varying amounts according to the fiber characteristics of viscosity and fermentability. Advantages of consuming fiber depend upon which type is consumed. Bulking fibers – such as cellulose and hemicellulose (including psyllium) – absorb and hold water, promoting bowel movement regularity. Viscous fibers – such as beta-glucan and psyllium – thicken the fecal mass. Fermentable fibers – such as resistant starch, xanthan gum, and inulin – feed the bacteria and microbiota of the large intestine and are metabolized to yield short-chain fatty acids, which have diverse roles in gastrointestinal health.

A tracheid is a long and tapered lignified cell in the xylem of vascular plants. It is a type of conductive cell called a tracheary element. Angiosperms also use another type of conductive cell, called vessel elements, to transport water through the xylem. The main functions of tracheid cells are to transport water and inorganic salts, and to provide structural support for trees. There are often pits on the cell walls of tracheids, which allows for water flow between cells. Tracheids are dead at functional maturity and do not have a protoplast. The wood (softwood) of gymnosperms such as pines and other conifers is mainly composed of tracheids. Tracheids are also the main conductive cells in the primary xylem of ferns.

The tracheid was first named by the German botanist Carl Gustav Sanio in 1863, from the German Tracheide.