Glossary
Agar - See agarose

Agarose - Agarose is a sugar, taken from seaweed. When it is mixed with water and heated up, then allowed to cool, it forms a gel. The higher concentration of agarose in the gel, the smaller the pores of the gel are.

Agrobacterium - Agrobacteria infect plants, causing a disease known as crown galls. The plasmids of agrobacteria are used in Gene Technology.

Amino Acid - Small molecules that form proteins, contains an amino (NH3) group and a carboxy (COOH) group, as well as a variable carbon-based group

Amplify - Amplify refers to the copying of DNA using Polymerase Chain Reaction

Anneal - Annealing refers to the binding of a single strand DNA to a primer, or second strand of DNA.

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Blunt Ends - Blunt ends occur when a restriction enzyme cuts both strands of DNA evenly.

Buffer - A buffer is a chemical compound that keeps the pH constant. In gel electrophoresis, the buffer serves as a conductor of electrical current.

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Carcinogen - A carcinogen is any compound that is suspected to cause cancer.

cDNA - Complementary DNA. This is a piece of DNA that is complementary to a specific mRNA strand

Cytoplasm - The cytoplasm is the fluid inside a cell that surrounds the organelles.

Cytosine - One of the four bases found in DNA.

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Denature - Denature means 'breaking apart'. In the case of DNA, denaturing causes the two strands of the DNA double helix to separate.

Differentiate - Cellular differentiation refers to a unprogrammed stem cell developing into a specialized cell. For example, an embryonic stem cell becoming the beginning of the brain stem.

Digestion - When restriction enzymes cut apart DNA, this is referred to as digestion.

DNA - DNA stands for deoxyribonucleic acid. DNA is the genetic material. DNA is comprised of a sugar backbone, connected by phosphate bonds. Each sugar has a one of four bases (adenine, guanine, thymine and cytosine) attached to it. DNA forms a double helix, with two strands of DNA bound together by base pairing. Adenine pairs with thymine, and guanine pairs with cytosine.

Donor egg - In cloning, the donor egg is an egg whose nucleus (and therefore, genetic material) has been removed.

Dopamine - Dopamine is a chemical signal in the brain that has many functions.

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Embryonic - Refers to the earliest stages of fetal development.

Ethidium Bromide - A flat chemical that reacts to UV light.

Expression - Expression of a gene refers to the gene being turned 'on' and producing a protein.

Extraction - Extraction refers to separating out one or two molecules from a solution.

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Fusion - Fusion of two cells means that the cells now share the contents of the cytoplasm and one membrane surrounds both cells.

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Genome - The genome is the entirety of an organism's genes.

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Herbicides - Herbicides are chemicals that kill plants. They usually target weeds.

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In Vitro - Refers to growing cells outside of the body (such as in a test tube or Petri dish), as opposed to "in vivo" (within the body).

Insecticides - Insecticides are chemicals that kill insects.

Intercalates - When a molecule intercalates, it slides between two parts of another molecule.

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Loci - Loci refers to multiple position on a chromosome. The singular form is locus.

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Methylation - Methylation refers to the addition of a methyl (CH3) group onto another molecule.

Methylene Blue - Methylene blue is a bright blue dye that stains nucleic acids.

Microliters - A microliter (abbreviated µl) is 1 x 10-6 liters (0.000001 liters = 1 microliter)

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Nucleotides - Nucleotide is another name for the bases in DNA. The four nucleotides found in DNA are: Adenine (A), Thymine (T), Guanine (G) and Cytosine (C).

Nucleus - The nucleus is an double-membraned organelle that serves as the site of storage for DNA. Also, transcription occurs there.

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Organelles - Organelles are cellular structures that serve a specific purpose. Some examples of organelles are: nucleus, mitochondria, ribosome, golgi body and chloroplasts.

Overhang - Refers to unpaired bases at the end of a double-stranded piece of DNA.

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Pellet - The pellet is the solid that forms at the bottom of the centrifuge tube after the mixture has been spun. The pellet consists of the heaviest particles found in the tube.

Plasmid - A plasmid is a circular piece of DNA. Scientists can build plasmids and use them to insert genes into bacteria or plants. A typical plasmid contains a promotor sequence, a marker sequence, a gene to be inserted, and a termination sequence.

Polymerase - An enzyme that adds nucleotides to a primer. There are many types of polymerase within cells, many of which specialize in certain tasks.

Primer - A primer is a short sequence (3-10) of nucleotides that binds to a single strand of DNA. Once the primer is bound, more nucleotides can be added so that the complementary strand of DNA is built.

Probe - A probe is similar to a primer, but a fluorescent molecule is attached to the short nucleotide sequence. When a gel electrophoresis is exposed to a probe, the short nucleotide sequence will bind to its complement, and that piece of DNA will then be visible because of the fluorescent molecule.

Promoter sequence - A promoter sequence, found in a plasmid, is designed to ensure that the plasmid is inserted in the correct area, and also that the gene in the plasmid is transcribed into RNA. The promoter sequence is usually similar to important genes found in the target organism.

Purified - When a substance is said to be purified, that means no other foreign substances are present.

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Ribosome - A cellular organelle comprised of protein and RNA.

Rotor - The rotor is tha part of the centrifuge that holds the tubes and spins.

RNA - Ribonucleic Acid. Usually single stranded, containing the nucleotides adenine, guanosine, cytosine and uracil. There are three main types of RNA: rRNA (ribosomal RNA), mRNA (messanger RNA) and tRNA (transfer RNA)

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SDS - Sodium Dodecyl Sulfate - a detergent that breaks up cell membranes.

Sequencing - Refers to deriving the string of nucleotides that from DNA.

Size marker - The size marker is typically a premixed set of DNA that contains known weights and sizes of DNA. This way, the unknown sample of DNA can be compared to the size marker DNA in order to determine a relative size and weight of the unknown sample.

Sticky Ends - Sticky ends are created when restriction enzymes do not cut at the same place on both strands of DNA. An overhang of unpaired bases occurs.

Supernatant - The supernatant is the thick liquid that forms at the top of the centrifuge tube after it has been spun. The supernatant contains the lighest particles that were originally found in the mixture.

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Taq Polymerase - Taq polymerase is an enzyme derived from bacteria. Taq polymerase is special, because it can withstand high temperatures, like those needed in polymerase chain reaction. Taq polymerase adds complementary nucleotides to a primer.

Transcription - During the process of transcription, the strand of DNA is unwound, and a polymerase forms a complementary strand of RNA. The process can be viewed in the form of a Flash movie: Transcription Movie

Transgene - A transgene is any gene that is inserted, or going to be inserted, into an organism other than what it came from.

Translation - During the process of translation, a ribosome reads RNA and converts the triplet codon into a string of amino acids.

Triplet Codon - A set of three nucleotides.

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Undifferentiated - Refers to cells which have not yet been specialized, such as stem cells.

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