misc Flashcards
H2O2 effect in proteins
H2O2 selectively oxidizes sulfhydryl groups of specific cystine residues, which are reversible and constitute a control mechanism of protein function
• Several targets
i. Protein tyrosine phosphatases (inactivates)
ii. Protein tyrosine kinases (activates)
iii. Small g proteins (activates GTPases)
iv. Transcription factor Nrf2 and NF-kB (activates)
list the enzymatic and non enzymatic detoxification
enyzmatic - sod, catalase, Glutathione peroxidase (also thioredoxins, Glutaredoxins, Peroxiredoxins)
non enymatic- Small molecules can act and antioxidants, reduced state can donate electrons to ROS to stabilize
Vitamin A, Vitamin E (lipid membrane), Vitamin C – cytosol , GSH
SOD
converts superoxide to hydrogen peroxide via a dismutase reaction
• Copper-zinc SOD (cytosol)
• Manganese SOD mitochondria
o Catalase
primarily in the peroxisomes, catalyzes the direct decomposition of H2O2 to water
o Glutathione peroxidase
removed H2O2 by using it to oxidize another GSH – a thiol-containing peptide
o Thioredoxings o Glutaredoxins (Grx)
repair damaged oxdaitive damage to amino acid side changes
o Peroxiredoxins (Prx)
class of H2O2 scavengers located in the cytosol, mito, peroxisomes, nucleus
alcohol effects at cellular level
inhibits the function of neurons by reducing the ability to transmit or fire electrical impulses
Two of the best-known effects of alcohol are its actions on GABA and glutamate
–> increases activity at GABAa receptor (inhibitory), functions as positive allosteric modulator –> Opens channel allowing small anions (Cl-) to pass in and out of the cell suppresses neuron firing
–> inhibit the activity of glutamate receptors, glutamate = excitatory, inhibition by alcohol leads to the reduction of neural activity
Long list of other synaptic effects
alochol effects on memeory
Loss of memory –> hippocampus (alcohol precvents the hippocampus from consolidating information that actually forms the memory), inhibits long term potentiation and neuogenesis (new memory formation)
o How does EtOH effect the hippocampus/new memory formation
o i. inhibits cell cycle – adult hippocampal neurogenesis (in dentate gyrus) is controversial (?)
o Apoptosis
Oxygen radicals
etoh assay kit
Assay kit, measures concentrations of EtOH by a dichromate method, dichromate is reduced by ethanol to a blush chromic product, the intensity of the colour is a direct measure of the alcohol concentration
Stats - 2 sample t-test to measure the mean of two groups, measures if these differences could happen by chance (5% change level set). Standard deviation is the measure of the amount of variation of a set of values
phase 1
oxidation (via chytochrome p450), reduction, and hydrolysis, making drug more polar to ointerating polar functional groups
phase 2 metabolism
glucoronidation, acetylation, and sulfation, conjugations to increase water solubility
maternal genetic variable and FASD
Maternal ADH and ALDH are found to be developmentally protective by reducing maternal plasma concentrations and fetal exposure to ethanol and acetaldehyde.
In three strains of maternal mice with differing levels of ADH, increasing maternal ADH activities correlated with decreasing maternal plasma ethanol concentrations and decreased fetal abnormalities (94
evidence for role of NOX in FASD
in mouse embryos exposed to EtOH, DPi (no inhibitor) ethanol increased ROS formation, oxidative DNA damage, embryonic caspase-3 activation and apoptosis were blocked –> but did not show proof that it prevented morphological and functional abnormalities
head space gas chromatography
head space –> used for samples with volatile and non volatile compounds, heats them up so you are only processing the volatile compounds
flame ionizing detection –> common for gas chromatography, will detect ions formed during combustion in a flame generated by hydrogen, using electrodes a current is generated propotional to the orgnanic compound
