Unit 3: Formation of ionic and metallic bonds Key unit competence: Describe how properties of ionic compounds and metals are related to the nature of their bonding 3.1. Introduction Activity 3.1 Look at the pictures above and answer the following questions. Record your answers and discuss them in your groups. 1) Observe carefully pictures A, B and C and suggest the similarity between them. 2) What can you say about the chloride and sodium ions in the pictures above? 3) What holds the chloride
Graves, Brad Hensler, Peter Hoholick Introduction Experiment 10: The Chemistry of Natural Waters investigates the topic known as water hardness. Hardness is a chemical property of water that evaluates the concentration of dissolved divalent cations such as Ca and Mg, which happen to be the two ions that are tested for in the experiment. Hardness can be measured in multiple ways such as molarity (M) or parts per million (ppm). Since all natural waters contain ion concentrations of
The term transformation is used when bacteria uptakes naked DNA from their environment through phagocytosis, and this DNA can be either linear or circular, like a plasmid, and is able to either be incorporated into the genome of the bacteria or exist within the cell with degradation. The purpose of using transformation as a laboratory technique is to introduce foreign DNA for many different uses like introducing a specific gene into the bacterial genome that produce a specific protein, medicine,
voltage-dependent inactivation at positive potentials (Figure XC). These channel properties are in good agreement with previously published data (Nilius…). A second set of experiment was devoted to chacterize the channel biophysical properties in the absence of divalent ions in the pipette, with the purpose to attenuate calcium-dependent inactivation (Citazione), a prerequisite for long duration experiments. Figure XD shows a record of 30 s long of the patch currents from an oxaliplatin treated neuron in the presence
Introduction: Bischofite is a hydrous magnesium chloride mineral with formula MgCl2•6H2O. It is a divalent cation electrostatiscally balanced by two chlorine atoms, plus six water molecules for every other atom. Bischofite is ecologically pure natural magnesium poly-mineral with a unique composition. It contains many macro- and micro-elements vital
2-Dark Reaction Three ecological varients that have different carbon dioxide incorporation mechanism have evolved during evolution that are C3, C4 and CAM plants. There is no net carbon dioxide assimilation until carbon dioxide during respiration is fully compensated by photosynthetic carbon dioxide fixation. The supply of carbon dioxide to the chloroplast occurs through diffusion process. C3 Plants: In these plants, first carbon dioxide fixation product is phosphoglycerate a three carbon compound
to the lumen apical. In the lumen, iron is ferric (Fe3+) and needs to be reduced to ferrous (Fe2+) to cross the plasma membrane. On the surface of the membrane, ferric iron (Fe3+) is converted to ferrous by ferric reductase. The symporter called Divalent-metal transports Fe2+ with protons into the cell. Iron is transported into the cell by active transport. When ferrous enters the epithelium some irons are converted to Fe3+ which are stored in the cell at the mucosal ferritin and lost by shredding
INTRODUCTION Lack of clean water is affecting millions of people today.Almost 1 out of every 6 people alive are unable to adequately access water, and worse still, over double that number lack basic sanitation, for which water is a necessity.(Abebe, 2011)Almost half the population in some third world countries can’t access clean water and availability of drinking water is becoming a major socio-economic issue across the world, particularly in the developing world. Clean water i.e. water that is free
There are many differences in between Mendeleev’s periodic table (that was first started in 1869) and today’s modern style periodic table. Mendeleev is known as the father of the periodic table. He had published a periodic table just five years after John Newlands had put forward his law of octaves. Mendeleev didn’t do all of the work on the periodic table though. He had some “help” from a few other scientists, chemists, and geologists. Although he was the first person to publish the first version
In this three-week long experiment conducted in the Bio 13 Lab, we were able to analyze a single nucleotide polymorphism (SNP) in our own genomic DNA and then determine our genotype at this specific SNP. In week one, we extracted genomic DNA from our cheek cells with swabs and prepared our DNA for PCR (Polymerase Chain Reaction) that would amplify the region with the intended SNP of interest. After one week and after the PCR was run outside of the lab section, the resulting PCR product was purified
Platelet-activating factor (PAF) or phospholipid, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine is a phospholipid activator and mediator of leukocyte functions that has many physiological actions. It was discovered and many studies have been done to characterize its messenger functions as a phospholipid.1 PAF is produced by many different cell types such as leukocytes, platelets, mast cells and vascular endothelial cells. PAF amplifies inflammatory responses by promoting leukocyte activation and
Chromium (Cr) is one of the known environmental toxic pollutants in the world which is from group VIII element of the first transition series and has a hard brittle gray transition metal with atomic number 24 and relative atomic mass 51.99 g/mol. Chromium is a naturally occurring element found in rocks, animals, plants, and soil. It can exit in several different forms and the most common forms are chromium, chromium (III) and chromium (IV). The major industrial application of chromium include the
Methylation is a product of complex processes that move and transform mercury. Atmospheric deposition contains the three principal forms of mercury, although inorganic divalent mercury (HgII) is the dominant form. Once in surface water, mercury enters a complex cycle in which one form can be converted to another. Mercury attached to particles can settle onto the sediments where it can diffuse into the water column, be resuspended, be buried by other sediments, or be methylated. Methylmercury can
under alkaline conditions.1,2 These enzymes are dimeric metalloenzymes containing two Zn2+, one Mg2+, and a serine residue in the active site of each monomeric subunit, in both prokaryotes and higher eukaryotes.2,3 Studies have shown that the three divalent cations are essential for enzymatic activity to catalyze the formation of an alcohol and an inorganic phosphate (Figure 1). In E. coli, the zinc ions are positioned to activate the serine and water for nucleophilic attack and ultimate cleavage of
Cadmium is present on the earth’s crust as heavy metal and its exposure in the environment is a very big challenge to environmentalist because cadmium is non-degradable in nature. In environment cadmium transfers from one trophic level to another and finally accumulated in human with toxic effects. There is an emerging need to remove the cadmium from the environment. Microbes are very helpful in this area to remediate the cadmium from the environment. Microorganisms used biotransformation and adsorption
1. Introduction Barium is a dense alkaline earth metal in Group IIA of the periodic table that occurs in nature as a divalent cation in combination with other elements. Gamma radiation is best absorbed by dense materials consisting of heavy atoms such as lead and barium [1]. Two commonly found forms of barium are barium sulfate and barium carbonate, often found as underground ore deposits. Shielding aprons manufactured from environmentally-friendly barium sulfate as a potential substitute for the
There are enzymes located on the intestinal brush border known as ferrireductases which reduce ferric iron to the more soluble ferrous state. Once reduced, the ferrous iron is then transported across the mucosal cells by the transporter protein divalent metal cation transporter 1
Samarium (II) Iodide A single electron transfer reagent useful for organic synthesis. A look into samarium (II) Iodide (Sml2), a powerful single electron donor which plays a vital role in the chemoselective reduction of certain functional groups and carbon-carbon bond formations. Cathal McKenna Student Number: 11322441 10/6/2014 Introduction Samarium (II) Iodide has emerged in recent times as a very useful reagent in organic synthesis. The compound was first used by Kagan and his researchers
1. Introduction Friedel–Crafts acylation of aromatic compounds is one of the most important and practical methods to prepare aromatic ketones. The resulting diaryl ketones are important chemical intermediates for the synthesis of a wide range of compounds such as pharmaceuticals, fragrances, flavors, dyes and agrochemicals [1,2]. This is an electrophilic acylation of aromatic compounds with acid chlorides or acid anhydrides, which is traditionally catalyzed by Lewis acids, such as AlCl3, BF3, SbCl5