Carbohydrates: carbon-containing compounds that are “hydrated” (that is, contain water). Composed of "carbon," "hydrogen," and "oxygen" "atoms." Most of the carbon atoms in a carbohydrate are linked to a hydrogen atom and a “hydroxyl group.” (Brooker, 45) Includes “sugars,” “starch,” and “cellulose.” (Hunt, 71)

Includes "monosaccharides," "disaccharides" and "polysaccharides." (Norman, 27) Atoms are present in a 1:2:1 ratio. For example, “glucose” is (C6 H12 O6). Biological properties include the storage of energy for plants and animals, providing a quick source of energy, and serving as structural components of plants and animals. They form rings in water. (Norman, 6/16/09)


Cellulose: structural component of plants. Humans cannot digest cellulose, but it is good for their digestion. (Norton Lectures, 6/16/09) Cows feed on grass but rely on "bacteria" in their guts to break down the cellulose to glucose. (Hunt, 72) One of the main components of plant cell walls. (Indge, 57)

Photosynthesis: the process by which plants are able to use light energy to convert "carbon dioxide" into carbohydrates. The equation is:

6CO2 + 6H2O -->  C6H12O+ 6O2

It does not mean that carbon dioxide is converted into "oxygen." Carbon dioxide is converted into carbohydrates and oxygen is produced as a waste product.  (Indge, 206) In green plants and algae, photosynthesis takes place in 'chloroplasts.' (Lawrence)

Starch: a polysaccharide found in plant cells. (Brooker, 46) Starch has a number of features which make it an ideal storage compound: its molecules are tightly coiled, allowing a considerable amount of starch to be packed into a relatively small volume; it is insoluble and therefore easier to store since it does not move out of cells readily, nor will it affect the water potential of a cell; (and) it is readily broken down by "enzymes" into glucose. The exact chemical composition of starch varies from one species of plant to another as it consists of two main components which may be present in different proportions. (Indge, 255-256) When people eat parts of plants, such as potatoes or rice, they can digest starch but not cellulose. (Hunt, 72)

Sugar(s): the general name for any monosaccharide, disaccharide, or trisaccharide. (Lawrence) Small carbohydrates that taste sweet. The simplest sugars are the monosaccharides. Sugar is often used as a source of energy by living organisms. (Brooker, 45)

Disaccharides: carbohydrates composed of two monosaccharides. Crystalline. Water-soluble. Sweet. “Hydrolysis” is needed before absorption into blood. (Norman, 6/16/09)

Lactose: milk sugar. Composed of glucose and galactose. (Norman, 6/16/09) Formed by the "condensation" of a molecule of glucose and a molecule of "galactose." (Indge, 115)

Maltose: malt or beer, sugar. (Norman, 6/16/09) Made from two glucose molecules joined together by a reaction in which a molecule of water is removed. (Indge, 82) It does not occur widely in the free stye, but is produce by germinating barley. (Lawrence)

Sucrose: table sugar. A familiar disaccharide composed of glucose and "fructose." (Norman, 6/16/09) A sugar made up of two sugar units. These units are glucose and fructose and they are joined together by a condensation reaction. Sucrose is a ‘non-reducing sugar’ and therefore will not produce a positive result with "Benedict’s test" unless it has first been hydrolyzed. (Indge, 258)

Monosaccharides: simple sugars. The most common types are molecules with five carbon atoms and six carbon atoms. Can join together to form larger carbohydrates. Examples include glucose,  fructose, and galactose. (Brooker, 44-45) Crystalline. Water-soluble. Biological properties include sweet to taste. Quick source of energy. Absorbed directly into the bloodstream. Quickly makes it to "mitochondria" to get "ATP" released for energy. (Norman, 6/16/09) Monosaccharide digestion begins in the mouth. (Norman, 6/23/09)

Hexose Sugars: sugars that have six carbon atoms in each of their molecules. Each molecule consists of a single sugar unit. (Indge, 136)

Fructose: a ‘ketone’ sugar that combines with glucose to make sucrose (table sugar.) Glucose + Fructose = Sucrose. (Norman, 6/16/09) Has the same molecular formula as glucose (C6 H12 O6), but the atoms that make up the molecule are arranged in a different way. It is found naturally in many fruits. An important constituent of ‘diabetic' diets as it tastes sweet but its "metabolism" does not depend on "insulin." (Indge, 114)

Galactose: an ‘aldehyde’ sugar that combines with glucose to make lactose or ‘milk sugar.’ Glucose + Galactose = Lactose. (Norman, 6/16/09) Has the same molecular formula as glucose, (C6 H12 O6), but the atoms that make up the molecule are arranged in a different way. (Indge, 115)

Glucose: (C6 H12 O6), the fuel for "neurons." The major energy source for the “muscles” and the sole energy source for the brain. (Ratey, 52) Glucose is the primary fuel for cellular metabolism. Glucose + Glucose = Maltose. (Norman, 6/16/09) Very water-soluble and thus circulates in the blood of animals and the fluids of plants, where it can be transported across “plasma membranes.” Once inside a cell, glucose is broken down by enzymes. The energy released in this process is used to make many molecules of ATP, which powers a variety of cellular processes. In this way, sugar is often used as a source of energy by living organisms. (Brooker, 45) The cells consume more glucose when they are active than when they are at rest. (The Brain, 6) All cells metabolize glucose to generate ATP. Glucose metabolism is simple. Other "macromolecules" can be converted to glucose. (Norman, 6/23/09) Plants make glucose by "photosynthesis." Some of the glucose they store as "starch," a reserve of energy food. Some of the glucose builds up the cellulose "cell walls" as the plants grow. (Hunt, 72)

Chitin: structural component of animals, "fungi," and insects. (Norton Lectures, 6/16/09) Long chain "polymer' of 'N-acetyle glucosamine.' It is the chief polysaccharide in 'fungal' cell walls and in the 'exoskeleton' of 'anthropoids.' (Lawrence)

Glycogen: storage molecule in animals. (Norton Lectures, 6/16/09) A molecule composed of glucose residues, that is the form in which carbohydrate is stored in the "liver" and in muscles. (Oxford) Formed by linking large numbers of 'alpha-glucose’ molecules into branched chains which are a characteristic feature of the structure of glycogen molecule. In a mammal, large amounts of glycogen may be found in the liver. Some is also stored in muscles. (Indge, 126) Also found in "bacteria" and fungi. (Lawrence)

Pentose Sugars: sugars that have five carbon atoms in each of their molecules. Includes "deoxyribose" and "ribose," which form part of the structure of the "nucleotides" which make up "DNA" and "RNA." (Indge, 201)

Deoxyribose: a five-carbon sugar found in DNA. (Brooker, G-10) Part of the structure of the nucleotides which make up DNA. (Indge, 200) Similar to "ribose" but lacking an oxygen atom. (Lawrence)

Ribose: the sugar in RNA. (Lawrence) Part of the structure of the nucleotides which make up RNA. (Indge, 200)

Polysaccharides: many monosaccharides linked together. Long polymers (meaning many sugars). (Brooker, 46) Composed of repeating glucose subunits. Variable bond formation (structure). Built from "monomers" of monosaccharides. (Indge, 214) Not sweet to taste. Not crystalline. Do not pass through cellular membranes. Not soluble in water - therefore they act as a good thickening agent. Hydrolysis is needed before absorption. (Norman, 6/16/09)

Glycosaminoglycans (GAGs): among vertebrates, the most abundant types of polysaccharides in the “extracellular matrix.” Long unbranched polysaccharides. Highly negatively charged molecules that tend to attract positively charged ions and water. The majority of GAGs in the extracellular matrix are linked to core proteins, forming “proteoglycans.” (Brooker, 194)

Pectin: a carbohydrate consisting of a mixture of polysaccharides. Found in and between plant cell walls, where it helps to cement the cellulose fibers together. Commercially very important in the extraction of fruit juices. (Indge, 201)