Year 10 Biology- Gene Technology

Nitrogenous base

Adenine, Thymine, Guanine, Cytosine and Uracil

Phosphodiester bond

A strong bond that joins phosphate and sugar molecules int he backbone of DNA

Hydrogen bond

A weak bond that joins the bases, connecting two strands of DNA

Deoxyribose

The sugar that makes up the backbone of DNA

DNA

A double stranded molecule that contains instructions for cell functions

Nucleotide

The repeating building block of DNA, made of a sugar, phosphate and nitrogenous base

Polymer

A large structure made of lots of repeating units

Chargaff's rule

%A=%T and %C=%G in a DNA molecule

Complementary base pairing

In DNA, A only pairs with T, and C only pairs with G

RNA

A single stranded molecule of genetic material found in cells

Ribose

The sugar found in RNA

Enzyme

A protein that speeds up the rate of a reaction

Substrate

The molecule(s) that the enzyme binds to at the start of a reaction

Product

The molecule(s) that are present at the end of a reaction

Active site

The 3D area of the enzyme that is complementary in shape to the substrate, and binds the substrate to catalyse a reaction.

Restriction enzyme

An enzyme that cuts DNA at a specific nucleotide sequence

Recognition site

The specific sequence of bases where a restriction enzyme cuts DNA

Restriction fragments

The DNA segments that result from the cutting of DNA by a restriction enzyme

Blunt ends

When a restriction enzyme cuts straight across a section of DNA leaving no overhangs

Sticky ends

When a restriction enzyme cuts across a section of DNA, leaving overhangs.

Denaturation

DNA is heated to 95 degrees, and separates into two single strands as hydrogen bonds break.

Annealing

DNA is cooled to 50 degrees and primers attach to the ends of the DNA strands.

Extending

DNA is heated to 72 degrees. Taq DNA Polymerase adds nucleotides to extend the primers and create complementary strands of DNA. The result is 2 copies of the original DNA molecule.

DNA standard

A DNA sample used in gel electrophoresis that contains fragments of DNA of known size. It is used to compare the sizes of unknown DNA fragments.

Positive electrode

The electrode found at the end of the agarose gel, that DNA fragments move towards

Negative electrode

The electrode found at the start of the agarose gel, that DNA fragments move away from

Plasmid

A small, circular section of DNA often found in bacteria

Recombinant plasmid

Plasmid that has been engineered to contain a gene of interest

Gene of interest

A gene for a desired trait that humans want to be expressed

Transformed bacteria

Bacteria that have taken up a plasmid

Transgenic organism

Organism that is genetically engineered to contain DNA from another species

Genetically modified organism

An organism whose genetic material has been altered

Competent

A bacterium that is able to take up plasmids from its environment