Covalent Bonding in Physiologically Important Ions and Molecules Flashcards
A Lewis dot symbol consists of the ________________ and one dot for ______________ in an atom of the element.
Symbol of an element, each valence electron
Valence electrons are…
the electrons that occupy the outmost shell of the atom or ion.
The term resonance itself means the use of…
two or more Lewis structures to represent a particular molecule.
The ________________ indicates that the structures shown are resonance structures.
double-headed arrow
Bond order indicates the…
approximate strength of a bond.
Bond order =
Number of Bonds/Number of connections between atoms
Discuss the characteristics of the molecule NO
- Involved in lowering blood pressure
- Neurotransmitter
- Antimicrobial defence
- Relaxes muscle cells in the cardiovascular system
Radicals are…
Radicals are very reactive chemical species with an unpaired electron.
Isoelectronic means…
Same number of electrons and the same connectivity in their structures.
They have the same number of atoms and the same number of bonds.
A ________________ substance is one with unpaired electrons and weighs heavier in the presence of a magnetic field. (attracted to magnetic field).
paramagnetic
Reactive oxygen species
Are oxygen species are made as by-products, which include Superoxide ion O2-Peroxide ion O22-Hydroxyl radical .OHHydroxyl ion OH-
Disproportionation (dismutation) reaction
This is a special type of redox reaction in which an element in one oxidation state is simultaneously oxidized and reduced.
This reaction is catalysed by the enzyme, superoxide dismutase.
What is the most reactive oxygen species?
Hydroxyl radical
Reactive oxygen species can:
Oxidize cholesterol
Oxidize unsaturated fatty acids
Causing membrane lipid peroxidation (oxidative degradation of lipids).
Reactive oxygen species can also react with a large variety of easily oxidizable cellular components, including NADH, NADPH, ascorbic acid, histidine, tryptophan, tyrosine, cysteine, glutathione, proteins and nucleic acids.
Peroxynitrite is an…
oxidant and nitrating agent. Because of its oxidizing properties, peroxynitrite can damage a wide array of molecules in cells, including DNA and proteins.
