BIO - TERMS - NUCLE Flashcards
amygdala
An almond-shaped nucleus in the anterior temporal lobe thought to be involved in emotion and certain types of learning and memory.
arcuate nucleus
A nucleus in the periventricular area of the hypothalamus containing a large number of neurons sensitive to changes in leptin levels, contributing to the regulation of energy balance.
basal forebrain complex
Several cholinergic nuclei of the telencephalon, including the medial septal nuclei and basal nucleus of Meynert.
CAAT box
A conserved nucleotide sequence in eukaryotic promoters involved in the initiation of transcription.
Chemical shift
The position on the NMR chart where a nucleus absorbs. By convention, the chemical shift of tetramethylsilane (TMS) is set at zero, and all other absorptions usually occur downield (to the left on the chart). Chemical shifts are expressed in delta units (d), where 1 d equals 1 ppm of the spectrometer operating frequency.
Cockayne syndrome
Neurological degeneration and early senility caused by inherited defects of transcription-coupled nucleotide excision repair.
consensus nucleotide sequence
A summary or “average” of a large number of individual nucleotide sequences derived by comparing many sequences with the same basic function and tallying up the most common nucleotides found at each position.
Coupling constant, J
The magnitude (expressed in hertz) of the interaction between nuclei whose spins are coupled.
de novo pathway
Pathway for the synthesis of a biomolecule, such as a nucleotide, from simple precursors; as distinct from a salvage pathway.
deoxyribonucleotides
Nucleotides containing 2-deoxy-D-ribose as the pentose component.
dorsal cochlear nucleus
A nucleus in the medulla that receives afferents from the spiral ganglion in the cochlea of the inner ear.
dorsal column nucleus
One of a pair of nuclei located in the posterior medulla; target of dorsal column axons, mediating touch and proprioceptive input from the limbs and trunk.
Doublet
A two-line NMR absorption caused by spin–spin splitting when the spin of the nucleus under observation couples with the spin of a neighboring magnetic nucleus.
Female gametophyte
A large thin-walled space within the ovule of the seed plant that contains the eight identical haploid nuclei derived by mitosis from the megaspore that was produced by meiosis.
FT-NMR
Fourier-transform NMR; a rapid technique for recording NMR spectra in which all magnetic nuclei absorb at the same time.
gustatory nucleus
A nucleus in the brain stem that receives primary taste input.
highly active antiretroviral therapy (HAART)
A combination of drugs that is used to control HIV infection. It comprises nucleoside analogs that prevent reverse transcription, and drugs that inhibit the viral protease.
Hutchinson-Gilford progeria
Premature aging caused by inherited defects in nuclear lamins.
inferior colliculus
A nucleus in the midbrain from which all ascending auditory signals project to the medial geniculate nucleus.
inferior olive
A nucleus of the medulla that gives rise to climbing fiber input to the cerebellar cortex. Climbing fiber activity is an important trigger for LTD, a form of synaptic plasticity believed to be important for motor learning.
Inosine
A nucleoside containing hypoxanthine and ribose.
lateral geniculate nucleus (LGN)
A thalamic nucleus that relays information from the retina to the primary visual cortex.
locus coeruleus
A small nucleus located bilaterally in the pons; using NE as their neurotransmitter, its neurons project widely to all levels of the CNS.
magic numbers
Certain numbers of nucleons (N or Z = 2, 8, 20, 28, 50, 82, and N = 126) that confer unique stability.
Male gametophyte
The three identical haploid nuclei within a pollen grain.
medial geniculate nucleus (MGN)
A relay nucleus in the thalamus through which all auditory information passes on its way from the inferior colliculus to the auditory cortex.
medial lemniscus
A white matter tract of the somatic sensory system carrying axons from dorsal column nuclei to the thalamus.
Meisenheimer complex
An intermediate formed by addition of a nucleophile to a halo-substituted aromatic ring.
metaplasticity
Activity-dependent modification of the rules of synaptic plasticity. MGN See medial geniculate nucleus.
Multiplet
A pattern of peaks in an NMR spectrum that arises by spin–spin splitting of a single absorption because of coupling between neighboring magnetic nuclei.
nuclear binding energy
The amount of energy that would be required to break apart the nucleus into its component nucleons.
nuclear equation
An equation that represents nuclear processes such as radioactivity.
nuclear fusion
The combination of two light nuclei to form a heavier one.
nuclear pore
An opening in the nuclear envelope through which materials enter and exit the nucleus.
nucleons
The particles that compose the nucleus and that are protons and neutrons.
Nucleophilic aromatic substitution reactions
The substitution reactions of an aryl halide by a nucleophile.
Nucleophilicity
The ability of a substance to act as a nucleophile in an SN2 reaction.
nucleus of the solitary tract
A brain stem nucleus that receives sensory input and uses it to coordinate autonomic function via its outputs to other brain stem and forebrain nuclei and to the hypothalamus.
optic radiation
A collection of axons coursing from the lateral geniculate nucleus to the visual cortex.
Phosphoribosyl pyrophosphate (PRPP)
The precursor of the ribose in purine and pyrimidine nucleotides.
positron emission
The form of radioactive decay that occurs when an unstable nucleus emits a positron.
prefrontal cortex
A cortical area at the rostral end of the frontal lobe that receives input from the dorsomedial nucleus of the thalamus.
primary gustatory cortex
The area of neocortex that receives taste information from the ventroposterior medial nucleus.
Quartet
A set of four peaks in an NMR spectrum, caused by spin–spin splitting of a signal by three adjacent nuclear spins.
ribonucleotide
A nucleotide containing D-ribose as its pentose component.
rubrospinal tract
A tract originating in the red nucleus and terminating in the spinal cord; involved in the control of movement.
salvage pathway
Pathway for synthesis of a biomolecule, such as a nucleotide, from intermediates in the degradative pathway for the biomolecule; a recycling pathway, as distinct from a de novo pathway.
Salvage reactions
Reactions that convert free bases to nucleotides.
Sandmeyer reaction
The nucleophilic substitution reaction of an arenediazonium salt with a cuprous halide to yield an aryl halide.
sn1 reaction
A unimolecular nucleo philic substitution reaction.
SN2 reaction
A bimolecular nucleophilic substitution reaction.
Spin–spin splitting
The splitting of an NMR signal into a multiplet because of an interaction between nearby magnetic nuclei whose spins are coupled. The magnitude of spin–spin splitting is given by the coupling constant, J.
superior olive
A nucleus in the caudate pons that receives afferents from the cochlear nuclei and sends efferents to the inferior colliculus; also called superior olivary nucleus.
suprachiasmatic nucleus (SCN)
A small nucleus of the hypothalamus just above the optic chiasm that receives retinal innervation and synchronizes circadian rhythms with the daily light–dark cycle.
Tegument
The layer interposed between the nucleocapsid and the envelope of herpesvirus particles. (Chapter 4)
transmutation
The transformation of one element into another as a result of nuclear reactions.
Variable number tandem repeat (VNTR) (minisatellite)
A highly polymorphic tandem repeat of a sequence of 10 to 80 nucleotide pairs in length.
ventral cochlear nucleus
A nucleus in the medulla that receives afferents from the spiral ganglion in the cochlea of the inner ear.
ventral lateral (VL) nucleus
A nucleus of the thalamus that relays information from the basal ganglia and cerebellum to the motor cortex.
ventral posterior (VP) nucleus
The main thalamic relay nucleus of the somatic sensory system.
ventral posterior medial (VPM) nucleus
The part of the ventral posterior nucleus of the thalamus that receives somatosensory input from the face, including afferents from the tongue.
vestibular nucleus
A nucleus in the medulla that receives input from the vestibular labyrinth of the inner ear.
vestibulospinal tract
A tract originating in the vestibular nuclei of the medulla and terminating in the spinal cord; involved in the control of movement and posture.
caudate nucleus
A part of the basal ganglia in the basal forebrain, involved in motor control.
cerebral nuclei
Paired irregular masses of gray matter buried deep within central white matter in the basal region of the cerebral hemispheres inferior to the floor of the lateral ventricle.
interstitial nuclei of the anterior hypothalamus (INAH)
Four neuron clusters in the preoptic area of the anterior hypothalamus in humans, some of which may be sexually dimorphic.
LINEs (long interspersed nuclear elements)
Families of long (average length = 6500 bp) moderately repetitive transposable elements in eukaryotes.
non-nucleoside inhibitor
A drug that binds with and inhibits the action of the HIV reverse transcriptase enzyme.
pontine nuclei
The clusters of neurons that relay information from the cerebral cortex to the cerebellar cortex.
pulvinar nucleus
A mass of neurons in the posterior thalamus that have widespread reciprocal connections with areas across the cerebral cortex.
raphe nuclei
Clusters of serotonergic neurons that lie along the midline of the brain stem from the midbrain to the medulla and project diffusely upon all levels of the CNS.
sexually dimorphic nucleus (SDN)
A neuron cluster in the preoptic area of the anterior hypothalamus that in rats is significantly larger in males than in females.
SINEs (short interspersed nuclear elements)
Families of short (150 to 300 bp), moderately repetitive transposable elements of eukaryotes. The best known SINE family is the Alu family in humans.
subthalamic nucleus
A part of the basal ganglia in the basal forebrain; involved in motor control.
