Amino Acid Chart: Videos & Practice Problems

The amino acid breakdown worksheet is designed to help you visualize and memorize the structures of amino acids, particularly focusing on their side chains. Each amino acid backbone is pre-drawn, allowing you to concentrate on adding the side chains, or R groups, which are crucial for understanding their properties. While some additional information, such as pKa values, is included for future reference, the primary goal is to create a comprehensive resource that you can use throughout your studies, even beyond your current course.

Starting with the non-polar amino acids, these are characterized by their hydrophobic nature, meaning they tend to avoid water and are often found in the interior of proteins. Glycine, the simplest amino acid, is unique as it is the only achiral amino acid, represented by the three-letter abbreviation Gly and the one-letter symbol G. Its structure is straightforward, consisting of a hydrogen atom as its side chain.

Next is alanine, which features a methyl group (CH₃) as its side chain. Its abbreviation is Ala, and its symbol is A, making it easy to remember as the simplest hydrocarbon. Valine follows, identifiable by its V-shaped side chain, and is represented by the letter V. Leucine is similar to valine but includes an additional CH₂ group, making it a more complex version, with the abbreviation Leu and symbol L.

Isoleucine, another variant of valine, also starts with a V but has an extra methyl group at the end. Proline is distinct as it forms a five-membered ring that connects back to its nitrogen, making it unique among amino acids. Its abbreviation is Pro, and its symbol is P.

Moving on to methionine, this amino acid introduces a heteroatom, sulfur, into its structure. The abbreviation is Met, and the symbol is M. Tryptophan is more complex, featuring a bicyclic aromatic ring structure. It is represented by the letter W, which can be remembered through a playful association with the character Elmer Fudd, who might mispronounce it as "triptophan." Lastly, phenylalanine is simply alanine with a phenyl group (a benzene ring) attached, abbreviated as Phe and symbolized by F.

To aid in memorization, a mnemonic device can be employed for the non-polar amino acids: "GABLIP," which stands for Glycine, Alanine, Valine, Leucine, Isoleucine, and Proline. For the additional three non-polar amino acids—methionine, tryptophan, and phenylalanine—you can remember them as occurring on "Monday, Wednesday, Friday." This structured approach not only helps in memorizing the amino acids but also in understanding their relationships and properties within proteins.

In the study of amino acids, the polar side chain category includes six important amino acids, each with unique structures and characteristics. To help remember these, we can use a narrative involving two sisters and their friends, which provides a memorable framework for understanding their properties.

The first two amino acids are cysteine and serine, represented by the sisters Sistine and Serene. Cysteine is notable for its thiol group (-SH), which can be remembered by Sistine's behavior of asking for quiet in the Sistine Chapel, symbolizing the -SH group. On the other hand, Serine enjoys a more lively lifestyle, akin to partying, which can be associated with its hydroxyl group (-OH) that resembles alcohol. This distinction highlights the functional groups that define their chemical behavior.

Next, we introduce Serene's friends, threonine and tyrosine, who also enjoy a good time. Threonine can be remembered as a "serious threat" due to its alcohol group, which is similar to serine but with an additional carbon, making it resemble valine. The structure of threonine can be visualized as a 'V' shape with an -OH group added, indicating its polar nature. Tyrosine, on the other hand, is characterized by its aromatic ring structure, similar to phenylalanine, but with an added hydroxyl group, making it "thirsty" for alcohol. This addition transforms phenylalanine into tyrosine, emphasizing the importance of functional groups in determining the properties of amino acids.

As the story continues, we meet two more friends, asparagine and glutamine, who join the group in the morning. Asparagine has a single carbon between its amide group (-CONH2), while glutamine has two carbons, reflecting the idea of "one ass and two glutes." This analogy helps to visualize the structural differences between the two amino acids. Both asparagine and glutamine are characterized by their amide functional groups, which can be remembered by their names ending in -ine, similar to amines.

In summary, the polar side chain amino acids—cysteine, serine, threonine, tyrosine, asparagine, and glutamine—can be effectively memorized through this engaging narrative. Understanding their structures and functional groups is crucial for grasping their roles in biological processes, as these properties influence their interactions and functions within proteins.

Amino acids are the building blocks of proteins and can be classified into acidic and basic categories based on their side chains. The two primary acidic amino acids are aspartic acid and glutamic acid. Aspartic acid is represented by the three-letter code ASP and the one-letter code D, while glutamic acid is denoted by GLU and E. A mnemonic to remember this is "drink acid" for D and "emergency room" for E.

Structurally, aspartic acid features a carbon atom connected to a carboxylic acid group, making it a biological acid. In contrast, glutamic acid has a more complex structure with two carbon atoms connected, where the second carbon is also linked to a carboxylic acid group, hence the name "glutamic" as it suggests being "glued" together.

On the other hand, basic amino acids include lysine, histidine, and arginine. Their three-letter codes are LYS, HIS, and ARG, respectively. The one-letter codes are K for lysine, H for histidine, and R for arginine. A helpful mnemonic for remembering these is "kittens hunt rats," inspired by the classic cartoon "Tom and Jerry."

Lysine resembles methionine in structure, with a carbon chain ending in an amine group (NH₂). Histidine is characterized by a carbon connected to a five-membered ring containing two nitrogen atoms, one of which is double-bonded. Arginine's structure is more complex, featuring a carbon connected to three nitrogen atoms and a carbon chain, which can be visualized as a triangle of amines, representing its three nitrogen atoms.

In summary, understanding the structures and codes of these amino acids is crucial for grasping their roles in biochemistry. Aspartic and glutamic acids are acidic, while lysine, histidine, and arginine are basic, each with unique structural characteristics that define their functions in proteins.

Amino acids are the building blocks of proteins, and they play a crucial role in various biological processes. While the body can synthesize many amino acids, there are specific ones known as essential amino acids that must be obtained through diet. These essential amino acids are vital for survival; without them, the body cannot function properly, leading to severe health consequences.

Essential amino acids cannot be produced by the body and must be sourced from external food sources, such as animal or plant proteins. The commonly accepted list of essential amino acids includes nine key amino acids: valine, leucine, isoleucine, methionine, tryptophan, phenylalanine, threonine, histidine, and lysine. It is important to note that some educational resources may include additional amino acids for specific health conditions, which can expand the list to ten or more.

To categorize these essential amino acids, they can be divided based on their properties. Six of them—valine, leucine, isoleucine, methionine, tryptophan, and phenylalanine—are classified as nonpolar or hydrophobic. Threonine is polar, while histidine and lysine are basic amino acids. Understanding these classifications can aid in memorization and comprehension of their functions.

For memorization, a helpful mnemonic is to think of the word "favorites," which can represent phenylalanine, valine, and threonine. The sequence continues with histidine, isoleucine, lysine, leucine, methionine, and ends with tryptophan, represented by the letter W. This approach simplifies the learning process by associating the amino acids with familiar terms and patterns in the alphabet.

In summary, essential amino acids are critical for maintaining health, and understanding their classifications and sources can enhance nutritional knowledge. Regular intake of these amino acids through a balanced diet is essential for overall well-being.

In this session, we focus on the essential amino acids, emphasizing their structures, names, and abbreviations through repetition and mnemonic devices. Understanding amino acids is crucial as they are the building blocks of proteins, and each has unique properties that influence protein structure and function.

To begin, we categorize amino acids into three main groups: nonpolar, polar, and charged (acidic and basic). The nonpolar amino acids can be remembered using the acronym "GAVLIP," which stands for Glycine (Gly), Alanine (Ala), Valine (Val), Leucine (Leu), Isoleucine (Ile), and Proline (Pro). Each of these amino acids has distinct side chains that contribute to their hydrophobic nature.

Next, we transition to polar amino acids, which include Cysteine (Cys), Serine (Ser), Threonine (Thr), and Tyrosine (Tyr). Mnemonics such as "alcohol is a serious threat" help recall Threonine's association with alcohol, while "trying to look cute" aids in remembering Asparagine (Asn) and its connection to glutes. The polar amino acids are characterized by their ability to form hydrogen bonds due to the presence of hydroxyl (-OH) or sulfhydryl (-SH) groups.

For the charged amino acids, we have the acidic side chains Aspartic acid (Asp) and Glutamic acid (Glu), which can be remembered as "ED" for their acidic properties. The basic amino acids include Lysine (Lys), Arginine (Arg), and Histidine (His), with memorable phrases like "Carla has a rack" to aid in recall.

When drawing the structures of these amino acids, it is essential to start with a common backbone, which consists of a central carbon atom bonded to an amino group (-NH₂), a carboxyl group (-COOH), a hydrogen atom, and a variable side chain (R group). For example, Glycine is unique as it is achiral, while other amino acids have specific configurations that can be represented in their structural formulas.

As we draw each amino acid, we pay attention to the specific features of their side chains. For instance, Methionine (Met) contains a sulfur atom, while Tryptophan (Trp) has an indole ring structure. The polar amino acids like Serine and Threonine are characterized by their hydroxyl groups, which play a significant role in biochemical reactions.

In summary, mastering the amino acids involves understanding their classification, memorizing their names and abbreviations, and being able to accurately draw their structures. This foundational knowledge is vital for further studies in biochemistry and molecular biology, as it lays the groundwork for understanding protein synthesis and function.