Biology Reference
In-Depth Information
Single nucleotide polymorphisms
(SNPs, point mutations) A
variantofDNAsequenceinwhichthepurineorpyrimidinebase(as
cytosine) of a single nucleotide is replaced by another such base (as
thymine). It is the most common type of change in DNA. SNPs occur
normally throughout a person's DNA once in every 300 nucleotides
on average, which means there are roughly 10 million SNPs in the
human genome. They can act as biologicalmarkers.
Strand break
An interruption of the sugar-phosphate backbone of
the nucleotide.
Supercoiled DNA
A contortion of circular DNA into the shape
of the simple figure eight. DNA supercoiling is important for DNA
packaging within allcells.
Tensammetry
Measurement of the interfacial capacitance as a
function of potential. It is used especially in the analysis of surface-
active substances that are notelectroactive [66].
Transducer
Part of the sensor/biosensor that converts a detected
physical or chemical change into a measurable (usually electronic)
signal. Working electrodes are used as transducers in electrochemi-
cal biosensors.
Voltammetry/polarography
Measurement of current as a function
of a controlled electrode potential and time, which results in a
current-voltage (or current-time or current-voltage-time) display,
commonly referred to as the “voltammogram” [66]. The working
electrode is situated typically in the voltammetric cell and is a
dropping mercury electrode in the case ofpolarography.
List of abbreviations
AC alternating current
AgSAE silversolid amalgam electrode
CNTs
carbon nanotubes
CP
capture probe
CPE
carbon paste electrode
DC
direct current
