The most important property of a water molecule is that due to an even distribution of electrons, it is slightly charged on each end. This type of bonding occurs between two of the same element or elements close to each other in the periodic table. An hydrogen bond is the attractive force between the hydrogen attached to an electronegative atom of one molecule of a different molecule. A hydrogen bond is formed when a charged part of a molecule having polar covalent bonds forms an electrostatic( charge, as in positive attracted to negative) interaction with a substance of opposite charge. The forces due to polarity are cohesion and adhesion.
Amino acids are considered to be strong acids because they have a strong charge on the amino group. This strong charge on the amino group creates an affinity for carboxylic acids to lose a proton. The isoelectric point, pI, is the pH of an aqueous solution of an amino acid at which the molecules have no net charge. In other words, the positively charged groups are exactly balanced by the negatively charged groups. When this dissolved amino acid is titrated with an acid it reacts like a base, and when titrated with base it acts like an acid.
It is a weak bond, but is decisive in controlling the structure of both water and ice. In a water molecule, two hydrogen atom are bonded to an oxygen atom share a pair of electrons between them by a covalent bond. In H2O, only two of the six outer-shell electrons of oxygen are used for this purpose, leaving four electrons which are organized into two non-bonding pairs. Salts are ionic compounds that result from the neutralisation reaction of an acid and an alkali. They are composed of an equal number of cations and anions so that the product is electrically neutral.
This is made by a phospholipid bi-layer containing hydrophilic heads made from a phosphate group and hydrophobic tails which are made from 3 fatty acids which is similar to a triglyceride. The head is facing outwards due to them being polar and so are water soluble & attracted to water, which leads to the hydrophilic tail being the membrane itself and facing away from the water. This makes the membrane partially permeable to lipid soluble molecules which can diffuse in, however water soluble molecules can’t unless their small in size. The bi-layer also contains extrinsic and intrinsic protein carriers (carrier proteins and protein channels), each having their own functions. Protein channels allow molecules that are too big to pass through the carrier proteins to enter in and out the cell via a tube shaped molecule via diffusion which requires a concentration gradient but then sometimes the molecules are too big to go through and therefore undergo facilitated diffusion, however carrier proteins only allow certain molecules with a complementary shape to the binding site of the carrier protein to enter using ATP as the main sources of energy.
This is because the less electronegative sodium has a weak Na-O bond and the oxygen is more easily given up to reacts with H+. Further along though, a strong S-O bond keeps this together and more H+ is generated. The amphoteric aluminium oxide has a bonding which is both ionic and covalent in nature. When these oxides are reacted with acids or bases, a neutralisation would occur with a salt and water produced. Aluminium oxide is amphoteric, meaning it react with both acid and
Given that silica is an absorbent, TLC is a “form of adsorption chromatography” (Varcoe 2001: 8-1). The silica gel used in the stationary phase is a highly polar compound capable of hydrogen bonding whereas in the mobile phase the solvent is a less polar compound, specifically ethyl acetate. | | Figure 1. Structure of silica gel particle (Varcoe 2001: 8-1) | Figure 2. Structure of Ethyl Acetate (Toxipedia 2010) | The polar interactions between the solutions and both of the absorbent and the solvent can occur as a dipole-dipole interaction, the result of the contact of two polar molecules with permanent dipoles such as hydrogen bonding and also dipole-induced dipole interaction in which a molecule with a permanent dipole polarizes another molecule.
The nephron itself will then restore the vital nutrients and water back into the blood, while retaining the waste products the needs to eliminate, through the proximal and distal tubules. When there are no diuretics in the blood, when tubular reabsorption occurs through the proximal tubule, selective reabsorption of nutrients, such a sodium ions, from the filtrate go back into the blood. So, when sodium ions are reabsorbed by the blood, negative ions such as chloride ions follow due to the charge attraction. The highly concentrated solutes create an osmotic force, so water is also reabsorbed and is also reabsorbed. Then the filtrate goes through the descending loop of Henle, which is permeable to water (water retained back), and then through the ascending loop of Henle, which is permeable to salt (salt is retained back).
1. Polarity is when electrons are not shared equally in a covalent bond, the molecule is described as polar. Capillary action is cohesion of water causes capillary attraction, which is the ability f water to move upward in small spaces. Surface tension is water that is considered the universal solvent because its bipolar molecule enables it to dissolve a wide variety of substances. Density is another property of water during phase changes.
If the substrate (key) doesn’t fit it won’t work with the enzyme (lock). This is important because without enzyme the processes would be to slow and poisonous chemicals would build up. The factors that affects if an enzyme would work correctly or not is if there is a suitable pH level and temperature. An example of an enzyme is Catalase. It is the one that we used in our experiment.
This is called the shaking and venting procedure. This procedure allows the benzoic acid (benzoic is the solute) to establish an equilibrium between the two layers the organic layer and the aqueous layer. Benzoic acid, although it has dissolve in water, is not very soluble in water (it will only dissolve in water at elevated temperature). However, benzoic acid is more soluble in methylene chloride. That is why once you add the benzoic acid aqueous solution and the CH2Cl2 in the separatory funnel the benzoic acid moves from the aqueous layer into the methylene chloride organic layer.