Thursday, May 27, 2010

Alga - Any of various chiefly aquatic, eukaryotic, photosynthetic organisms, ranging in size from single-celled forms to the giant kelp. Algae were once considered to be plants but are now classified separately because they lack true roots, stems, leaves, and embryos
Allele - One member of a pair or series of genes that occupy a specific position on a specific chromosome. (Simplification: A blond hair gene and a black hair gene are both found in the same spot on the genome. Some people have one, some the other, but only one can be there. Thus the two are alleles)
Amino Acid - Any of a large number of compounds that are found in living cells, contain carbon, oxygen, hydrogen, and nitrogen, and join together to form proteins. (Building blocks of proteins)
Apoptosis - Disintegration of cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding. (Cell Death)
ATP (Adenosine Triphosphate) - A multifunctional nucleotide primarily known in biochemistry as the "molecular currency" of intracellular energy transfer. In this role ATP transports chemical energy within cells. (The main type of energy used in cells. Think gasoline in cars)
Cambrian explosion - The geologically sudden appearance of complex multi-cellular macroscopic organisms between roughly 542 and 530 million years ago. This period marks a sharp transition in the fossil record with the appearance of the earliest members of many phyla of metazoans (multicellular animals).
Cyanobacterium - A photosynthetic bacterium of the class Coccogoneae or Hormogoneae, generally blue-green in color and in some species capable of nitrogen fixation. Cyanobacteria were once thought to be algae. Also called blue-green alga. (Keyword: photosynthetic. These bacteria get energy from light)
DNA (Deoxyribonucleic acid) - A nucleic acid that carries the genetic information in the cell and is capable of self-replication and synthesis of RNA. DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. The sequence of nucleotides determines individual hereditary characteristics.
Endorphin - Any of a group of peptide hormones that bind to opiate receptors and are found mainly in the brain. Endorphins reduce the sensation of pain and affect emotions.
Eukaryote - An organism whose cells contain a nucleus surrounded by a membrane. All organisms except for bacteria, cyanobacteria, and the bacteria-like organisms known as archaea are eukaryotes. (Keyword: Nucleus)
Gene - A segment of DNA, occupying a specific place on a chromosome, that is the basic unit of heredity. Genes act by directing the synthesis of proteins, which are the main components of cells and are the catalysts of all cellular processes. Physical traits, such as the shape of a plant leaf, the coloration of an animal's coat, and the texture of a person's hair, are all determined by genes.
Genome - 1. The total genetic content contained in a haploid set of chromosomes in eukaryotes, in a single chromosome in bacteria, or in the DNA or RNA of viruses. 2. An organism's genetic material.
Histone - Any of several small, basic proteins most commonly found in association with the DNA in the chromatin of eukaryotes. (DNA "wraps" around these in order to coil in a cell and save room)
Interferon - Any of a group of glycoproteins that are produced by different cell types in response to various stimuli, such as exposure to a virus, bacterium, parasite, or other antigen, and that prevent viral replication in newly infected cells and, in some cases, modulate specific cellular functions.
junk DNA - Collective label for the portions of the DNA sequence of a chromosome or a genome for which no function has yet been identified. About 98.5% of the human genome has been designated as "junk", including most sequences within introns and most intergenic DNA.
Mitochondria - A spherical or elongated organelle in the cytoplasm of nearly all eukaryotic cells, containing genetic material and many enzymes important for cell metabolism, including those responsible for the conversion of food to usable energy. (Power House of cells)
Mutation - 1.A change of the DNA sequence within a gene or chromosome of an organism resulting in the creation of a new character or trait not found in the parental type. 2. The process by which such a change occurs in a chromosome, either through an alteration in the nucleotide sequence of the DNA coding for a gene or through a change in the physical arrangement of a chromosome.
Obligate - 1. Able to exist or survive only in a particular environment or by assuming a particular role: an obligate parasite; an obligate anaerobe. 2. Absolutely indispensable; essential. (It has to be or use something)
Phenotype - 1a. The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences. b. The expression of a specific trait, such as stature or blood type, based on genetic and environmental influences. 2. An individual or group of organisms exhibiting a particular phenotype. (The physical expression of genes; eye color for example)
Prion - A microscopic protein particle similar to a virus but lacking nucleic acid, thought to be the infectious agent responsible for scrapie and certain other degenerative diseases of the nervous system. (This mutant protein causes mad cow)
Prokaryote - Any of a wide variety of one-celled organisms that lack a distinct cell nucleus or other structures bound by a membrane and that have DNA that is not organized into chromosomes. Prokaryotes reproduce asexually, are the most primitive and ancient known forms of life, and include the bacteria and blue-green algae. (No Nucleus)
Retrovirus - Any of a group of viruses, many of which produce tumors, that contain RNA and reverse transcriptase, including the virus that causes AIDS. (These viruses can turn RNA into DNA, which is virtually unheard of anywhere else. Normal Transcriptase makes RNA from a DNA template, reverse transcriptase works in, well, reverse)
RNA (ribonucleic acid) - The nucleic acid that determines protein synthesis in all living cells and the genetic makeup of many viruses. RNA consists of a single strand of nucleotides in a variety of lengths and shapes and is mainly produced in the cell nucleus. (Different from DNA because it uses the base Uracil instead of Thymine and a slightly different sugar backbone)
Telomere - Either of the sections of DNA occurring at the ends of a chromosome.
Virus - Submicroscopic parasitic particle that infects cells in biological organisms. (Usually a protein shell containing RNA or DNA. Replicates by entering a host cell and hyjacking its replication machinery to spawn copies. Antibiotics have no effect on them)
a group of organisms in a self-sufficient community naturally occupying a small area with a uniform environment throughout.

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