Biology Reference
In-Depth Information
wrapped. Chromatin fibre is composed of a string of nucleosomes, like
a pearl necklace where each pearl is a nucleosome (see
Chromatin
).
Ontology
: Ontology is the area concerned with indemonstrable
first principles. In discussions in the realm of ontology, one is often
induced to say that an entity is not real, for example, species or
the individual organism. This means that it is not a first princi-
ple constituting what is real. For example, for a nominalist, the
species is not real in that it depends on subjective classification
by a classifier.
Phenotype
: All the qualitative (e.g. eye colour) or quantitative
(e.g. size) characteristics of an individual resulting from the expres-
sion of its genes.
Phosphatase
: Post-translational modification enzyme dephosphory-
lating (removing phosphate from) proteins (see
Protein synthesis
).
Post-genomic biology
: This term refers to the research programme
that has been developing since sequencing the human genome. It is
not strictly defined. One of its aspects consists in vastly widening
programmes for collating data on proteins and RNAs (to include
proteomes and transcriptomes) and in devising computer tools to
analyse them. This modelling more and more often involves the
participation of mathematicians and physicists.
Post-translational modifications
: See
Protein synthesis
.
Prokaryote
: Simple cell without a nucleus delimited by a mem-
brane, e.g. bacteria.
Promoter:
DNA sequence situated upstream of the genes where the
enzyme allowing their transcription binds (See
Protein synthesis
).
Protein synthesis
: The nucleotide sequence (the genetic information)
of DNA is first of all transcribed into RNA (transcription). This
