Jones reagent versus PCC

In organic chemistry students will learn both Jones (CrO3/ aq H2SO4) and PCC reagents and will need to know how to differentiate between the

Prions and prion disease

Prion is a misfolded version (wrong secondary and tertiary structure) of prion protein that is transformed to an infectious particle that le

Effect of different inhibitors on Km and Vmax

Enzymes are biological catalysts that help to speed up the rate of reactions. All enzymes have two very important factors, Km and Vmax. V max is the maximum speed of the enzyme. Km is the concentration of substrate needed for the enzyme to work at half of its maximum speed. The lower the km, the better the enzyme is and the higher it's affinity for substrate is. Inhibitors are molecules that inhibit or diminish the productivity of an enzyme. There are three different types of inhibitors. Competitive inhibitor competes with the substrate for the active site on the enzyme. It resembles the substrate in it's shape and look. Competitive inhibition can be overcome if much more substrate is added

How to calculate pH of the weak acid.

If the question is asking for a pH, the first thing we need to recognize is whether we are dealing with acid or base and whether it is strong or weak? Strong acids are the following: HCl - hydrochloric acid, HNO3 - nitric acid, H2SO4 - sulfuric acid, HBr - hydrobromic acid,HI - hydroiodic acid, HClO4 - perchloric acid, HClO3 - chloric acid. If an acid is not one of these, it is a weak acid. Moreover, if ka value is given for your acid, then there is a 99% chance that it is weak as well, unless the professor wants to trick you by giving you a very high ka value. Weak acids dissociate very little and that is why we can't use regular stoichiometry for their calculations, but rather have to use

State the general trend in first ionization energy as the elements in Period 3 are considered from l

First ionization energy is the amount of energy needed to take first electron from an atom. The trend for ionization energy is that it increases from the bottom to the top and from the left to the right. Why? The bigger an atom's radius is, the further away outer electrons from the pulling of the nucleus are and the less energy is needed to take them away. Thus, ionization energy trend is opposite of that of radius. Therefore, as the elements in Period 3 are considered from left to right, the first ionization energy will increase since the radius decreases in this direction. The ionization energy for the second electron is much greater than first, since it's harder to put a charge on an alre

Shortcut to finding pI of an amino acid

Isoelectric point or pI is a ph at which an amino acid or protein has a net charge of zero. Biochemistry classes always ask students to find pI for an amino acid and here is the short and sweet way to do it. For neutral amino acids, two pka's will be given, and pI = (pKa1 + pKa2)/2 For acidic amino acids ( aspartic acid and glutamic acid), we average out the two lowest pka, so we do not take into account the amino terminal pka For basic amino acids such as arginine, we average out the two highest pka, so we do not take into account the carboxylic acid pka. For more help with biochemistry or chemistry classes, contact our incredible chemistry tutors in NYC, Brooklyn, and online and call 646-4