3 prime (3’) end– DNA can only be read by polymerase in one direction. The 3′ end is where polymerase can start reading (moving toward the 5′ end)
Band– when many copies of the same DNA fragment move together through an electrophoresis gel. The pattern of bands reveals the number of different size DNA fragments in a sample.
Base pair– a pair of nucleotide bases in the double stranded DNA double helix structure. Base pairs form the ‘rungs’ on the DNA ladder.
Centrifuge– a machine that spins tubes really fast so that the solid components form a pellet in the bottom of the tube.
Chromosome– DNA is found in large molecules in the nucleus known as chromosomes. Each chromosome is composed of thousands of genes. During cell division, chromosomes duplicate and divide, maintaining the genetic integrity of the organism.
Complementary– refers to the normal nucleotide-pairing in DNA replication. Cytosine pairs with guanine and adenine pairs with thymine.
DNA replication– the copying of a DNA molecule or a portion of it.
Extraction buffer– a salt solution that helps break down cell membranes so the DNA can be released into the solution.
Gel electrophoresis– a technique which uses electricity to separate molecule fragments according to size so they can be studied.
Genomic DNA– the genetic material found in the nucleus (in chromosomes).
Nucleotides– The subunits that are linked together to make DNA or RNA.
PCR (polymerase chain reaction)– A method for making lots of copies of a particular gene or sequence of DNA in the lab. PCR is used to generate greater amounts of DNA for analysis or to determine if a particular DNA sequence exists.
Polymerization– adding subunits to a polymer. Example: adding nucleotides in DNA replication.
Precipitate– the solid that forms when a chemical is added to a solution.
Primer– small section of DNA nucleotides which bind to the single-stranded DNA template during PCR. These sequences serve as a starting point for polymerase to start copying a strand of DNA.
Reaction buffer– a solution that helps prevent changes in pH
Restriction enzyme– a protein that can recognize a particular DNA sequence and cut it.
TAQ polymerase– A highly heat stable type of DNA polymerase that can withstand the heat used during PCR. The heat in PCR separates the strands of DNA so TAQ polymerase can read the strands of DNA and create a complementary strand of DNA. This enzyme is what performs the ‘photocopying’ of the DNA.
Transgenic– ‘Trans’ means to move across and ‘gen’ refers to gene…so transgenic is an organism that has new genetically engineered DNA sequence found in every one of its cells. Genetically engineered organisms are transgenic. These two terms are used interchangeably.