UCMP Glossary: Biochemistry
alginate -- component of the cell walls of many rhodophytes and kelps. Alginates have an affinity for water, and so help to slow dessication when the algae are exposed to the air; they are commercially important in the production of paper, toothpaste, beer, and frozen foods.
brevitoxin -- neurotoxin produced by the dinoflagellate Ptychodiscus brevis.
calcium carbonate -- n. A white compound, CaCO3, that occurs naturally as marble, chalk, limestone, and calcite. It is used by many marine invertebrates, such as corals and echinoderms, and by protists, such as coccolithophorids, to construct their exoskeletons. Calcium carbonate, in the form of calcite, is also incorporated into the eggshells of amniotes, except for turtles whose eggs are composed of aragonite (CaCO3 + magnesium).
cathodoluminescence -- n. An analytical technique used in geology and paleontology to analyze the different minerals in a sample, or diagenetic history of a sample how crystals grew, were deformed, and were replaced. A beam of electrons is fired at a sample to produce visible light, which can then be used to interpret the mineralogical and diagenetic history of the sample.
cellulose -- carbohydrate polymer of the simple sugar glucose. It is found in the cell walls of plants and green algae, as well as dinoflagellates. Cellulose is the most abundant compound on earth that is manufactured by living things.
chlorophyll -- n. The green-colored pigment that absorbs light during photosynthesis, often found in plants, algae, and some bacteria; it includes a porphyrin ring, and often has a long hydrophobic tail. More info?
dinosteranes/dinosteroids -- chemicals found in dinoflagellates, which have been useful in documenting their existence early in the fossil record.
DNA -- "deoxyribonucleic acid". The nucleic acid which carries the genetic code of an organism. It is the primary component of chromosomes. MORE?
flagellin -- protein which is the primary component of prokaryotic flagella.
fucoxanthin -- yellowish-brown pigment found in some members of the Chromista, including kelps and diatoms.
glycoprotein -- a membrane-bound protein which has attached branching carbohydrates. These may function in cell-cell recognition, such as in human blood groups and immune system response, as well as in resisting compression of cells.
hemoglobin -- protein complex found in the blood of most chordates and the roots of certain legumes. It binds oxgen molecules, and in chordates serves as the means by which the oxygen is supplied to the cells of the body.
histones -- proteins attached to the DNA of eukaryotes which allows it to be packaged into chromosomes.
integrin -- adhesive protein of the extracellular matrix in animals.
isotopic analysis -- n. The study of the geochemistry of stable isotopes in naturally occurring sediments and biological structures. Stable isotopes are atomic variations of elements that are stable over long periods of time, meaning they do not radioactively decay. Several elements, like oxygen and carbon, have several stable forms. Oxygen, for example, occurs in nature as 16O and 18O — these two forms are isotopes. They have different numbers of neutrons (16O has two more neutrons than 18O), and and is therefore heavier. Because the two isotopes have different masses, chemical and physical reactions like bonding, evaporation, and precipitation occur at different frequencies. The ratio of stable isotopes is preserved in chemical compounds like water, ice, and calcium carbonate and provides information on the environmental conditions at the time the compound formed. For example, the ratio of 18O/16O in an ice sample is linked to the water temperature of ancient oceans, which in turn reflects ancient climates.
laminarin -- a beta-glucan polysaccharide produced by many chromists through photosynthesis.
nucleic acid -- class of biochemical compounds which includes DNA and RNA. They are among the largest molecules known. MORE?
peptidoglycan -- carbohydrate polymer cross-linked by proteins. It is found in the cell wall of Gram positive bacteria, where it stains with the dye crystal-violet.
pigment -- any colorful compound, used by living things to absorb or block sunlight, and in sexual displays. More info?
RNA -- "ribonucleic acid". The nucleic acid which carries the DNA message into parts of the cell where it is interpreted and used. The 18S ribosomal RNA sequence has been used in many groups of organisms to reconstruct phylogeny.
scanning electron microscope (SEM) -- n. A special kind of microscope that scans samples with a high-energy beam of electrons to produce a high-resolution, detailed, three-dimensional image. An SEM can magnify a sample up to 250 times that of the best light microscopes.
spongin -- proteinacous compound of which the spicules in Demospongiae are composed.