Instruct: Given a question, retrieve documents that answer the question.
Query: What is the most common carbohydrate?
The term is most common in biochemistry, where it is a synonym of 'saccharide', a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides, the smallest (lower molecular weight) carbohydrates, are commonly referred to as sugars.[3] The word saccharide comes from the Greek word σάκχαρον (sákkharon), meaning "sugar".[4] While the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose, as in the monosaccharides fructose (fruit sugar) and glucose (starch sugar) and the disaccharides sucrose (cane or beet sugar) and lactose (milk sugar).
Once consumed, the carbohydrates found in the gels are absorbed into the blood to supply the body with calories and nutrients to fuel exercise activity by helping to delay muscular fatigue, raise blood sugar levels, and enhance performance. Most energy gels have no fat, fiber, or protein, so they can be digested quickly. They contain mainly sugars and maltodextrins, which make them similar to sports drinks without the water. Since simple carbohydrates slow down gastric emptying and can cause gastrointestinal distress in athletes, there are attempts to create new categories of energy gels made with complex, long chain carbohydrates and/or fat. Spring gel is an example of a gel with low sugar, low glycemic index carbohydrate content with the addition of fat and Vespapower is an example of a gel made with fat. Some gels, such as e-Gel, also come with added electrolytes. There are also gels with extras such as ginseng and other herbs, amino acids, vitamins, and Coenzyme Q10. Caffeine can be found in some gels as well. Examples of common energy gels are GU, PowerBar Gel, and Clif Shot.
CBMs of microbial glycoside hydrolases play a central role in the recycling of photosynthetically fixed carbon through their binding to specific plant structural polysaccharides. CBMs can recognise both crystalline and amorphous cellulose forms. CBMs are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. Many putative CBMs have been identified by amino acid sequence alignments but only a few representatives have been shown experimentally to have a carbohydrate-binding function.
Depending on quantities, the number of grams of carbohydrate in a food can have a bigger impact on blood sugar levels than the glycemic index does. Consuming less dietary energy, losing weight, and carbohydrate counting can be better for lowering the blood sugar level. Carbohydrates impact glucose levels most profoundly, and two foods with the same carbohydrate content are, in general, comparable in their effects on blood sugar. A food with a low glycemic index can have a high carbohydrate content or vice versa; this can be accounted for with the glycemic load (GL) where GL= GI% x grams of carbohydrate per serving (Louie JCY, "et al"., 2015]. Consuming carbohydrates with a low glycemic index and calculating carbohydrate intake would produce the most stable blood sugar levels.
Most vegetables are low- or moderate-carbohydrate foods (in some low-carbohydrate diets, fiber is excluded because it is not a nutritive carbohydrate). Some vegetables, such as potatoes, carrots, maize (corn) and rice are high in starch. Most low-carbohydrate diet plans accommodate vegetables such as broccoli, spinach, kale, lettuce, cucumbers, cauliflower, peppers and most green-leafy vegetables. 
Common chemical shift ranges for nuclei within carbohydrate residues are:
There is evidence that the quality, rather than the quantity, of carbohydrate in a diet is important for health, and that high-fiber slow-digesting carbohydrate-rich foods are healthful while highly-refined and sugary foods are less so. People choosing diet for health conditions should have their diet tailored to their individual requirements. For people with metabolic conditions, in general a diet with approximately 40-50% high-quality carbohydrate is compatible with what is scientifically established to be a healthy diet.
Various forms of transferrin exist, with differing levels of sialylation. The most common form is tetrasialotransferrin, with four sialic acid chains. In persons who consume significant quantities of alcohol (usually more than 4 or 5 alcoholic beverages a day for two weeks or more), the proportion of transferrin with zero, one, or two sialic acid chains is increased. These are referred to as "carbohydrate-deficient transferrins". These carbohydrate-deficient transferrins can be measured in the bloodstream, and are an important marker for alcohol abuse. 
There are some similarities and many differences inherent in the character of biopolymer backbones. The backbone of each of the three biological polymers; proteins, carbohydrates, and nucleic acids, is formed through a net condensation reaction. In a condensation reaction, monomers are covalently connected along with the loss of some small molecule, most commonly water. Because they are polymerized through complex enzymatic mechanisms, none of the biopolymers' backbones are formed through the elimination of water but through the elimination of other small biological molecules. Each of these biopolymers can be characterized as either a heteropolymer, meaning it consists of more than one monomer ordered in the backbone chain, or a homopolymer, which consists of just one repeating monomer. Polypeptides and nucleic acids are very commonly heteropolymers whereas common carbohydrate macromolecules such as glycogen can be homopolymers. This is because the chemical differences of peptide and nucleotide monomers determines the biological function of their polymers whereas common carbohydrate monomers have one general function such as for energy storage and delivery.
The primary sequence of ovotransferrin is similar to that of many serum transferrins found in other species. Recently, scientists have discovered a blood serum transferrin in humans, that binds iron like ovotransferrin and which shows 50% homology to ovotransferrin, i.e., they have similar amino acid composition and carbohydrate content. At the C- lobe, human serum has two N-glycans while the hen ovotransferrin has a single N-glycan. Consequently, structurally this protein differs from its serum counterpart because of its glycosylation pattern. These proteins are said to be glycosylated because they have carbohydrates attached to them. Glycosylation is the most common covalent modification (formation of chemical bonds) that occurs in living organisms. This process is determined by the structure of the protein backbone and the carbohydrate attachment site.
Carbohydrate consumed in food yields 3.87 kilocalories of energy per gram for simple sugars,[20] and 3.57 to 4.12 kilocalories per gram for complex carbohydrate in most other foods.[21] Relatively high levels of carbohydrate are associated with processed foods or refined foods made from plants, including sweets, cookies and candy, table sugar, honey, soft drinks, breads and crackers, jams and fruit products, pastas and breakfast cereals. Lower amounts of carbohydrate are usually associated with unrefined foods, including beans, tubers, rice, and unrefined fruit.[22] Animal-based foods generally have the lowest carbohydrate levels, although milk does contain a high proportion of lactose.
The main principles that are adhered to are that fat and sugar should be completely avoided, and carbohydrates and salt should be kept at a minimum. Protein is always to be quite high during any stage of body building as it has a major involvement in muscle repair and maintenance. The time in which carbohydrates are eaten are usually in the morning with breakfast and thereafter in very small portions with meals. It is common for those ripping to have a protein shake after a workout as it helps with the muscle damage that has taken place during the workout. During the ripping period, the protein shake that is consumed usually contains zero or very little amounts of carbohydrates. Most meals usually contain a piece of meat or fish with vegetables. If the person ripping wishes to include carbohydrates then it would often be foods low in fat like potato, rice or pasta fruits and vegetables often in smoothie (blended) form.
Nectar is collected by foraging worker bees as a source of water and carbohydrates in the form of sucrose. The dominant monosaccharides in honey bee diets are fructose and glucose but the most common circulating sugar in hemolymph is trehalose which is a disaccharide consisting of two glucose molecules. Adult worker honey bees require 4 mg of utilizable sugars per day and larvae require about 59.4 mg of carbohydrates for proper development.
Even though glycosylation is the most common form of protein modification, with highly complex carbohydrate structures, the bioinformatics on glycome is still very poor. 
Carbohydrate dehydrogenases are the most common quinoprotein oxidoreductases, which are enzymes that oxidize a wide range of molecules.
Low-carbohydrate diets or carbohydrate-restricted diets (CRDs) are diets that restrict carbohydrate consumption. Foods high in carbohydrates (e.g., sugar, bread, pasta) are limited or replaced with foods containing a higher percentage of fats and moderate protein (e.g., meat, poultry, fish, shellfish, eggs, cheese, nuts, and seeds) and other foods low in carbohydrates (e.g., most salad vegetables such as spinach, kale, chard and collards), although other vegetables and fruits (especially berries) are often allowed.
There is a lack of standardization of how much carbohydrate low-carbohydrate diets must have, and this has complicated research. One definition, from the American Academy of Family Physicians, specifies low-carbohydrate diets as having less than 20% carbohydrate content.
Low-carbohydrate diets are associated with increased mortality, and they can miss out on the health benefits afforded by high-quality carbohydrate such as is found in pulses, fruit and vegetables. Disadvantages of the diet might include halitosis, headache and constipation, and in general the potential adverse effects of the diet are under-researched, particularly for more serious possible risks such as for bone health and cancer incidence.
Carbohydrate-restricted diets can be as effective, or marginally more effective, than low-fat diets in helping achieve weight loss in the short term. In the long term, effective weight maintenance depends on calorie restriction, not the ratio of macronutrients in a diet. The hypothesis proposed by diet advocates that carbohydrate causes undue fat accumulation via the medium of insulin, and that low-carbohydrate diets have a "metabolic advantage", has been falsified by experiment.
It is not clear how low-carbohydrate dieting affects cardiovascular health; any benefit from HDL cholesterol might be offset by raised LDL cholesterol, which risks causing clogged arteries in the long term.
Carbohydrate-restricted diets are no more effective than a conventional healthy diet in preventing the onset of type 2 diabetes, but for people with type 2 diabetes they are a viable option for losing weight or helping with glycemic control. There is little evidence that low-carbohydrate dieting is helpful in managing type 1 diabetes. The American Diabetes Association recommends that people with diabetes should adopt a generally healthy diet, rather than a diet focused on carbohydrate or other macronutrients.
An extreme form of low-carbohydrate diet – the ketogenic diet – is established as a medical diet for treating epilepsy. Through celebrity endorsement it has become a popular weight-loss fad diet, but there is no evidence of any distinctive benefit for this purpose, and it risks causing a number of side effects. The British Dietetic Association named it one of the "top 5 worst celeb diets to avoid in 2018".
Since carbohydrate is the macronutrient that raises blood glucose levels most significantly, the greatest debate is how low in carbohydrates the diet should be. This is because although lowering carbohydrate intake will help reduce blood glucose levels, a low-carbohydrate diet conflicts with the traditional establishment view that carbohydrates should be the main source of calories. Recommendations of the fraction of total calories to be obtained from carbohydrate are generally in the range of 20% to 45%, but recommendations can vary as widely as from 16% to 75%.
It is suggested that ingestion of monosaccharides at low concentrations during the race could delay glycogen depletion. This lower concentration, as opposed to a high concentration of monosaccharides, is proposed as a means to maintain a more efficient gastric emptying and faster intestinal uptake of this energy source. It is thought that carbohydrates are the most efficient source of energy for ATP. Pasta parties and the consumption of carbohydrates in the days leading up to a marathon are common practice of marathon runners at all levels.
What has not generally been included in diabetic diet recommendations is the variation in effect from different carbohydrates. It has been recommended that carbohydrates eaten by people with diabetes should be complex carbohydrates.
Organisms typically cannot metabolize all types of carbohydrate to yield energy. Glucose is a nearly universal and accessible source of energy. Many organisms also have the ability to metabolize other monosaccharides and disaccharides but glucose is often metabolized first. In Escherichia coli, for example, the lac operon will express enzymes for the digestion of lactose when it is present, but if both lactose and glucose are present the lac operon is repressed, resulting in the glucose being used first (see: Diauxie). Polysaccharides are also common sources of energy. Many organisms can easily break down starches into glucose; most organisms, however, cannot metabolize cellulose or other polysaccharides like chitin and arabinoxylans. These carbohydrate types can be metabolized by some bacteria and protists. Ruminants and termites, for example, use microorganisms to process cellulose. Even though these complex carbohydrates are not very digestible, they represent an important dietary element for humans, called dietary fiber. Fiber enhances digestion, among other benefits.[23]
Carbohydrate content of foods is listed on the Nutrition Facts panel as “total carbohydrate”. Some food labels will list specific types of carbohydrate, such as “fiber, sugar, or other carbohydrate”. With carbohydrate counting, the “total carbohydrate” is used as the carbohydrate amount. Carbohydrate counting can be done by either adding up grams of total carbohydrate or adding "carbohydrate units". A carbohydrate unit is simply 15 g of carbohydrate.
The most common theory of the Vada Pav's origin is that it was invented in the erstwhile mill-heartland of Central Mumbai, then known as "Bombay". The carbohydrate-rich snack catered to the mill workers of what then known as Girangaon. The combination of the potato dumpling ("batata vada") placed inside a "pav" quickly became popular in Girangaon and later the rest of Mumbai. Despite the ethnocentrism in Maharashtra, Vada Pav is claimed to be a part of the culture of Marathis despite the concept of a sandwich (a filling of potato within slices of bread) being western.
Carbohydrates are typically stored as long polymers of glucose molecules with glycosidic bonds for structural support (e.g. chitin, cellulose) or for energy storage (e.g. glycogen, starch). However, the strong affinity of most carbohydrates for water makes storage of large quantities of carbohydrates inefficient due to the large molecular weight of the solvated water-carbohydrate complex. In most organisms, excess carbohydrates are regularly catabolised to form acetyl-CoA, which is a feed stock for the fatty acid synthesis pathway; fatty acids, triglycerides, and other lipids are commonly used for long-term energy storage. The hydrophobic character of lipids makes them a much more compact form of energy storage than hydrophilic carbohydrates. However, animals, including humans, lack the necessary enzymatic machinery and so do not synthesize glucose from lipids (with a few exceptions, e.g. glycerol).
Lectin affinity chromatography is a form of affinity chromatography where lectins are used to separate components within the sample. Lectins, such as concanavalin A are proteins which can bind specific alpha-D-mannose and alpha-D-glucose carbohydrate molecules. Some common carbohydrate molecules that is used in lectin affinity chromatography are Con A-Sepharose and WGA-agraose. Another example of a lectin is wheat germ agglutinin which binds D-N-acetyl-glucosamine. The most common application is to separate glycoproteins from non-glycosylated proteins, or one glycoform from another glycoform. Although there are various ways to perform lectin affinity chromatography, the goal is extract a sugar ligand of the desired protein.
Comprising 75% of the biological world and 80% of all food intake for human consumption, the most common known human carbohydrate is Sucrose. The simplest version of a carbohydrate is a monosaccharide which contains carbon, hydrogen, and oxygen in a 1:2:1 ratio under a general formula of CHO where n is a minimum of 3. Glucose is an example of a monosaccharide as is fructose. Combine them in the picture shown to the right and you have sucrose, one of the more common sugar products around.