Amino Acid Peptide Linkage Formation and Hydrolysis Reactions

Amino acids are the building blocks of living things. This makes the process of making/breaking bonds critical to understanding biological sciences. This video walks you through the formation of an amino acid bond – the peptide bond, as well as breaking the bonds through hydrolysis. (Watch on YouTube: Peptide Linkage/Hydrolysis. Click CC for transcription) Links […]

Peptide Charge and Isoelectric Point Shortcut

Charge and isoelectric point of peptides are determined by the individual amino acids. Both the backbone groups (N and C terminus) and the individual side chains. The previous video showed you how to find the charge and pI of individual amino acids. This tutorial shows you how to find them for a group of amino […]

Isoelectric Point of Amino Acids with MCAT shortcut

Isoelectric point calculations are critical in your biochemistry course and MCAT prep. The isoelectric point or pI gives you the pH at which the molecule has a net zero charge. This comes from a balance of protonation and deprotonation so that all positive and negative charges cancel out. This video shows you how to calculate […]

Zwitterion and Amino Acid Charge Tutorial Video

Amino acids exist as zwitterions at physiological pH. A zwitterion by definition is a molecule with 2 (zwitter) ions, one positive and one negative for a net zero charge. This video shows you how to quickly calculate amino acid charge at any given pH by helping you recognize when a given side chain is protonated or […]

Strecker Synthesis of Amino Acids

Strecker Synthesis is one of the first laboratory methods for synthesizing an alpha amino acid. Strecker synthesis starts out with a nucleophilic addition of nitrogen to an aldehyde followed by a SECOND nucleophilic addition of cyanide (nitrile group) to the imine intermediate. This video walks you through the overall reaction followed by a step by step […]

Gabriel Malonic Ester Synthesis of Alpha Amino Acids

Gabriel Malonic Ester Synthesis is the second AAMC required reaction for the synthesis of alpha amino acids. As the name implies, this reaction utilizes Gabriel Amine Synthesis and Malonic Ester Synthesis, but with a twist. This video shows you the reaction overview followed by a step by step breakdown of important mechanism steps. (Watch on […]

Amino Acids Practice Quiz

Amino acids are a big deal on the MCAT. You can’t simply ‘get’ the concept. You must be able to quickly recall information and apply them to questions. The quiz below will help you figure out if you’ve mastered this topic. The questions are simple but thorough. You either know it, or you don’t! Be sure […]

Stereochemistry of Amino Acids RS to DL

Amino acids are biologically active molecules. 19 of the 20 common amino acids have a chiral alpha carbon, 2 amino acids (Leucine and Threonine) have a second chiral center in their side chain. This video shows you how to Find R/S for 3-D amino acids Find R/S and D/L for amino acid Fischer projections Trick […]

Amino Acids 3 Polar Acidic and Basic Side Chains

Hydrophilic amino acids are much more reactive and interactive compared to hydrophobic side chains. This video breaks down the hydrophilic amino acids including polar neutral, acidic and basic side chains. (Watch on YouTube: Polar/Acidic/Basic Amino Acids. Click cc on the bottom right for video transcript) Referenced in this video: Acid Base Tutorial Series Zwitterion Tutorial […]

Amino Acids 2 Hydrophobic Non-Polar Side Chains

Hydrophobic amino acids have neutral non-polar side chains. Given the lack of polarity these groups have no means to interact with an aqueous biological environment. This video breaks down each of the hydrophobic amino acids to help you understand the name, 1 and 3 letter abbreviations, and side chain functional groups. (Watch on YouTube: Hydrophobic […]