Amino acids classification

, they are the monomers of proteins. Find out how amino acids are classified into four categories based on their properties and how they form proteins through DNA transcription and translation. May 26, 2024 · amino acid, any of a group of organic molecules that consist of a basic amino group (―NH 2 ), an acidic carboxyl group (―COOH), and an organic R group (or side chain) that is unique to each amino acid. The correspondence between structure-based and sequence-based analyses of the same proteins shown here allow them to be used in future analyses of the Jan 15, 2022 · Complete mnemonics about all types of amino acids. Unlike other amino acids, proline has a secondary amino group. In addition to the amino and carboxyl groups, amino acids have a side chain or R group attached to the α-carbon. A biomolecule is carbon based organic compound which is produced by living organisms. Dec 24, 2022 · Amino acids are the monomers that make up proteins. 1. There are 20 types of amino acids which are coded by the gene of vertebrate but large numbers of modified (non-standard) amino acids are found in proteins. Each amino acid is linked to another by an amide (or peptide) bond formed between the amine group of one and the acid group of the other. As five features are able to separate 32 elements, exactly 12 groups visible at the bottom of the chart remain Oct 9, 2020 · All naturally occurring amino acids contain in common a central α-carbon atom to which a carboxylic group, an amino group, and a hydrogen atom are covalently bonded. As many as 300 amino acids are found in nature but only 20 amino acids are standard as they Figure 1. NONESSENTIAL AMINO ACIDS. 1 13. The products obtained upon hydrolysis of simple proteins are all amino acids. 4. Summary of Amino Acids Classification system for amino acids based on their metabolic fate: Glucogenic amino acids: These are precursors of gluconeogenesis, which results in glucose production. Essential amino acids vary considerable from one organism to another and even differ in humans, depending on whether they are adults or children. Conversely, essential amino acids must be acquired from The 8 Essential Amino Acids. The chemical configuration of AAs is generally defined in reference to l- and You might imagine that changing a single amino acid in a protein consisting of a hundred or more amino acids would have little effect on the protein’s folded shape or function. Amino acids are the fundamental units of protein or polypeptides. Such amino acids are also referred to as --- 3. Jun 10, 2020 · Classification. Aspartic acid. They are carboxylic acids with a carboxyl group, primary amine group ( except Proline) and a variable side chain (R group) attached to the α Carbon atom. Table 2. A full discussion of pH effects for each of these AA types is down below. Amino acids are organic compounds that contain both an amine ( \ce {-NH2}) and a carboxylic acid ( \ce {-COOH}) group in the same molecule. Non-polar, 2. Within the context of G-protein coupled receptor (GPCR) classification, an optimization algorithm was developed, which was able to identify the most efficient grouping when used to generate local descriptors. Classification based on the structure: b. Derived amino acids. According to polarity of side chains, amino acids are of four types: 1. Every protein at least contains a primary, secondary 1. Dec 22, 2023 · Amino acids are organic compounds that serve as the building blocks of proteins. Feb 28, 2023 · Note that tyrosine is both polar and aromatic. Amino acids with a polar (hydrophilic) positively charged side chain Aug 5, 2011 · 1. Sep 15, 2008 · Amino Acids. Many are modifications of the standard amino acids. Amino acids can be shown with or without charges. alanine, valine, leucine. Some amino acids can be synthesized in the body, but others (essential amino acids) cannot and must be Nomenclature of Amino acids is shared under a CC BY-NC-SA 4. Types of amino acids: There are 21 common amino acids commonly found in proteins, each with a different R group (variant group) that determines its chemical nature. 8. May 9, 2023 · Threonine. Introduction. Amino acids are necessary for the healthy existence of an organism (e. Through repeated binary separation at the corresponding median of five features F(i) the amino Oct 7, 2022 · Editorial Team. In protein molecules the α-amino acids are linked to each other by peptide bonds between the amino group of one amino acid and the carboxyl group of its neighbour. They are structurally and chemically different, and also differ in size and volume. In total, there are twenty types of amino acids that the body needs to build and repair body tissues, absorb nutrients, and other processes necessary for your health. As their classification suggests, the side chains tend to be repelled from water, so this impacts the positioning of these amino acids in the protein tertiary structure. There are twenty different amino acids, and the body can synthesize eleven of them. The acidic amino acids are glutamic acid (glutamate) and aspartic acid (aspartate). In taste, few Amino acids are sweet, tasteless, and bitter. The amino acids whose side chains are always neutral have isoelectric points ranging from 5. Valine. Khan Academy is a nonprofit with the mission of providing a free, world-class Sep 18, 2020 · Overview of the presented classification approach. Chemistry is a physical science, and it is the study of the properties of and interactions between matter and energy. It has various implications in real-life applications, making it a vital part of some fascinating fields. They have a very high melting and boiling point. be/dEgGq-KNiPAAmino acids lecture part 2 - Importance of each amino acids General properties of Amino acids. Amino acids are the building blocks of proteins. Feb 2, 2023 · Classification of amino acids and their function in the body. The 3rd thing you need to know: Animals of Africa. Dec 22, 2021 · Your body uses amino acids to make proteins. This amino acid is unionized, but if it were placed in water at pH 7, its amino group would pick up another hydrogen and a positive charge, and the hydroxyl Figure 2. Structural features of amino acids. non-polar amino acids. Classification of amino acid on the basis of side chain, chemical composition, Nutritional Requirement and metabolic fate. Basic. A protein can be identified based on each level of its structure. There are eleven non-essential amino acids. They can be classified according to the core structural functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side-chain group type (aliphatic, acyclic, aromatic, containing Dec 10, 2022 · At its pI, the positive and negative charges on the amino acid balance, and the molecule as a whole is electrically neutral. Lysine plays a vital role in building muscle, maintaining bone strength, aiding recovery from injury or surgery, and regulating It is a component of pantothenic acid, HOCH 2 C (CH 3) 2 CH (OH)CONHCH 2 CH 2 CO 2 H, a member of the vitamin B complex and an essential nutrient. 3. These amino acids are hydrophobic in nature and cannot participate in hydrogen bonding and ionic bonding. Oct 17, 2018 · Amino acids: General properties and classification. One of the most common ways to classify amino acids is based on human health requirements. Amino acids are white crystalline solid substances. - These are the building units of proteins. There are 20 standard amino acids that are the basic building blocks of proteins in Jul 28, 2023 · Asparagine. Each amino acid has an α-carboxyl group, a primary α-amino group, and a side chain called the R group (see Image. The algorithm was inspired by the relatively new computational intelligence paradigm of art …. Some amino acids can be synthesised by the body. memorizing amino acids is just like a game,amino acid single letter codehelp you to memorize 20 amino acid within a minute. Identify the classification of the given amino acid: polar, nonpolar, basic or acidic. The non-amino acid portions of Jun 25, 2020 · pH and pKa relationship https://youtu. Valina. The α carbon, carboxylic acid, and amino Amino acids are the monomers that comprise proteins. Alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, methionine, proline, serine and valine are some of the amino acids found Nov 23, 2023 · Actually, three branched-chain amino acids constitute over 2/3 of the amino acids in the body proteins, pointing out that its role for humans is invaluable. What is the mnemonic to remember the basic amino acids? Study with Quizlet and memorize flashcards containing terms like Glycine, Gly, G, Alanine, Ala, A, Valine, Val, V and more. Which of the following amino acids has a net negative charge at physiologic pH (~7. Amino acids are organic compounds containing amine [- NH 2] carboxyl [-COOH] side chain [R group] The major key elements if amino acids are carbon, hydrogen, nitrogen, oxygen. They contain an amino group, carboxylic acid group, alpha carbon, and side chain. 0 license and was authored, remixed, and/or curated by LibreTexts. All have "special" biological functions. There are over 500 known amino acids, though only 20 are used in proteins. Figure 3. Sep 21, 2023 · Draw Fisher projections and assign D/L or R/S stereodescriptors to proteinogenic amino acids. Optical properties of amino acids. Figure 5 shows one example in which the substitution of a single amino acid Chemistry. Such amino acids are also referred to as ---. Each protein is a molecule made up of different combinations of 20 types of smaller, simpler amino acids. Figure 13. Metagenomic taxonomic classifiers analyze either Sep 18, 2020 · Overview of the presented classification approach. 2. A protein consists of one or more chains of amino acids (called polypeptides) whose sequence is encoded in a gene. Nov 13, 2017 · classification of Amino acids. Amino acids help: Break down food. protein synthesis); moreover, new medical discoveries correlate the presence of amino acids in serum and other physiological fluids with many diseases and metabolic disorders [1]. This is an important process in the 1 day ago · An amino acid is the fundamental molecule that serves as the building block for proteins. It is present in many sweet fruits, such as bananas or red fruits. Oct 11, 2017 · General structure of amino acid Specific learning objective (SLO): Amino acid as Ampholytes (acid and base), Zwitter ions. Understand the classification of proteinogenic amino acids based on the characteristics of the side chain. Grow and repair body tissue. Animal proteins all contain every single one of these essential amino acids, so they're called complete proteins. Amino acids are the monomers that make up proteins. 1 3. Chemical structure of L-Valine Identifiers and properties of Valine. For example, alanine, shown on the right, is an amino acid. If there are less than 10 amino acids the molecule is called a peptide; if 10 to 100 a polypeptide; and more than 100 a 'protein. The term amino acid is short for α-amino [alpha-amino] carboxylic acid. PLIX - Play, Learn, Interact and Xplore a concept with PLIX. They consist of an amino group (-NH2), a carboxyl group (-COOH), and a side chain (R group), all bonded to a central carbon atom. The 21st amino acid, not shown here, is selenocysteine, with an R group of -CH 2-SeH. -Proline pertains to the second group in column 2 and for the In this article we will discuss about the classification and properties of amino acids. The 3rd thing you need to know: Body Parts. Amino acids are the building blocks of the polyamide structures of peptides and proteins. 1: Amino acid structure: Amino acids have a central asymmetric carbon to which an amino group, a carboxyl group, a hydrogen atom, and a side chain (R group) are attached. Polar but neutral, 3. The basic amino acids (which have positively charged side chains at neutral pH) have relatively high pIs. May 20, 2024 · Metabuli enhances metagenomic read classification by jointly analyzing DNA and amino acid sequences for specificity and sensitivity, respectively. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha ( α) carbon, bonded to an amino group (NH 2 ), a carboxyl group (COOH), and to a hydrogen atom. They carry out a wide variety of organism functions, including DNA replication, transporting molecules, catalyzing metabolic reactions, and providing structural support to cells. Jul 23, 2022 · Classification of Amino Acids on the basis of polarity Amino acid with non-polar side chain . Acidic and 4. Amino Acid Generic Structure). Acetyl coenzyme A is a pyrophosphorylated derivative of a pantothenic acid amide. Make hormones and brain chemicals (neurotransmitters). Each molecule contains a central carbon (C) atom, called the α All amino acids are capable of forming zwitterions, but this only happens at a specific pH value which is unique for each amino acid. Each amino acid has the same fundamental structure, which consists of a central carbon atom, also known as the alpha (α) carbon, bonded to an amino group (NH 2 ), a carboxyl group (COOH), and to a hydrogen atom. Mar 21, 2024 · Nutritionists divide amino acids into two groups - essential amino acids (must be in the diet because cells can’t synthesize them) and non-essential amino acids (can be made by cells). Acid-Base properties and Buffer characteristic. The different types of amino acids and the way they’re put together determine the function of each protein. Although more than 100 amino acids occur in nature, particularly in plants, only 20 types are commonly found in most proteins. Polar amino acids. Define isoelectric point and understand the ionization states of amino acids under physiological conditions. acids are more soluble in water than the non -polar amino acids, due to -OH, -NH 2, amide and -SH functional groups that can interact with water; 3. If you don’t eat foods that Dec 25, 2020 · Proteins are large molecules made from smaller building blocks called amino acids. Apr 30, 2024 · Proteins are made up of 20 amino acids. The gamma-amino homolog GABA is a neurotransmitter inhibitor and antihypertensive agent. Here the classification, based on the polarity of the side chains is discussed. These are equivalent structures. Some are branched structures, some …. Most amino acids have a chiral carbon, which allows them to rotate polarized light. Learn with flashcards, games, and more — for free. Classification based on the composition of “-R’ side chain. They include: Phenylalanine, the three Branched Chain Amino Acids Valine, Leucine and Isoleucine, Lysine, Threonine, Tryptophan, and finally Methionine. Although the body can produce many amino acids, it cannot synthesise these eight amino acids and they must be sourced from diet. As a result, they must come from food. The basic amino acids are lysine, histidine, and arginine. Amino acids can be either polar or non-polar based on their ---. Eg: GABA (Gamma Amino Butyric Acid) 2. See how they are classified by the chemistry of the side chain: polar-uncharged, polar-charged and non-polar. Longest Answer: Planets of the Solar System. At the center of each amino acid is a carbon called the α carbon and attached to it are four groups – a hydrogen, a carboxylic acid group, an amine group, and an R-group, sometimes referred to as a variable group or side chain. Short amino acid polymers called peptides also play important roles as hormones, hormone-releasing factors, neuromodulators, or neurotransmitters. e. About 500 amino acids are known (though only 20 appear in the genetic code) and can be classified in many ways WHAT ARE AMINO ACIDS. Receptors, G-Protein-Coupled. The struc Apr 24, 2015 · General structure of amino acid Specific learning objective (SLO): Amino acid as Ampholytes (acid and base), Zwitter ions. Histidine is essential for infants Jun 1, 2004 · Classification of amino acids according to the Taylor [80,79] critera is one of the most accepted methods in Biochemistry. Every amino acid also has another atom or group of atoms bonded to the alpha carbon known Jul 4, 2016 · Background Physicochemical properties are frequently analyzed to characterize protein-sequences of known and unknown function. The side chain varies among different amino acids, giving each its unique properties. Term. (a) Common structure of α-amino acids, position of the α-carbon is labeled; ‘R’ represents any number of possible chemical structures, which may be as simple as a single hydrogen atom (–H, as in the amino acid glycine) or more complex chemical groups, as in (b); (b) Examples of naturally occurring amino acids, with different ‘R’ groups. The amine and carboxyl groups of an amino acid are both covalently bonded to a central All amino acids have the same basic structure, shown in Figure 2. , side chain). Most of the amino acids are soluble in water and are insoluble in organic solvents. Amino acids can have either an L- or D- configuration, but only the L- form is found in the human body. Jan 31, 2022 · Learn the names, symbols, structures and properties of the 20 amino acids derived from proteins. 1 shows essential and non-essential amino acids in humans. They are the basic unit of proteins. A few are found in proteins. 1: An amino acid is an organic molecule that contains an amine group, a carbonyl group, and a side chain (R) ( R), all bonded to a central carbon atom. For this purpose many scales classifying amino acids according to their physicochemical properties There are about 300 "non-standard" amino acids found in biological systems. For instance, the classification of amino acids on a dietary basis (essential and nonessential) informs diet planning and nutrition regulation. They are separated into two groups; short range and long range forces. The R groups of these Jan 26, 2018 · Amino acids are carboxylic acid in which α-carbon is attached to the amino group as well as it is attached to R- (alkyl) group. Protein molecules are long chains of amino acids that are folded into a three-dimensional Chemistry. Classification of Amino Acids: Amino acids may be classified in several different ways. Essential Amino Acids These types of amino acids can’t be produced by the body and must come from the food you eat. The side chain varies from one amino acid to the other. So in This article, we will Memorize amino acids in five minutes. Cysteine and cystine can be interconverted readily with a wide variety of oxidizing and reducing agents according to the general reaction 2RSH [ O] ⇌ [ H] RSSR. Amino acids with a polar (hydrophilic) negatively charged side chain (at pH = 6): aspartic acid and glutamicacid; 4. How are amino acids joined together? The amino acid can be connected by a condensation reaction in which the nucleophilic addition-elimination reaction between the amino group of one amino acid and the carboxyl group of another amino acid forms a covalent bond (peptide bond), and releases one molecule of Jul 30, 2020 · Classification. Amino acids are basic building blocks of proteins and have many functions in the metabolism of a living organism. Valine regulates the use and secretion of other amino acids, and is also a source of energy for the body’s muscles. Oct 12, 2019 · Histidine. Aug 22, 2023 · What is an amino acid? Learn about the structure, classification, types and functions of amino acids in this fun video. These are classified as non-essential amino acids. Fundamental amino acid structure: a basic amino group, an acidic carbonyl group, and a variable “R” group which gives an amino acid its properties. Zwitterions are important for encouraging substances to dissolve in the water present in the body- this is important for a lot of things and allows the chemical reactions we need to occur. In addition, the α-carbon atom binds a side chain group called R group which is distinctive for each amino acid. In this manner a polymeric structure of repeating amide links is built into a chain or Jan 1, 2021 · Download Citation | Amino Acids: Chemistry and Classification | Amino acids (AAs) contain both amino and acid groups. If you're an ovo-lacto-vegetarian (you eat eggs and dairy products), you can get complete proteins from those foods. In general, amino acids are non-polar if --- are present. Multiplication table 1-10. Often this is the case, but sometimes a single change makes a profound difference. The structural, fibrous proteins are presented first, because their structure is simpler than that of the globular proteins and more clearly related to their function, which is . Food scientists and dietitians Amino acid classification based on human nutrition. - All amino acids have the same basic structure. 5. Amino Acids (Structures and Classification) Amino Acid. This classification of amino acids has little to do with the structure of amino acids. Amino acids can be classified in several ways, including by their side chain properties, polarity, distribution in proteins, and nutritional requirements Feb 16, 2017 · Top Contributed Quizzes in Science. 0 to 6. 1: Classification and Nomenclature of Amino Acids. All proteogenic amino acids are α-amino acids. Every amino acid also has another atom or group of atoms bonded to the central atom known Sep 15, 2022 · Classification. Tryptophan. Some must be taken in through food, others can be produced by your body, and then there are also amino acids that you Study with Quizlet and memorize flashcards containing terms like What functional groups are present in all amino acids?, 1. In humans (and other eukaryotes), Oct 31, 2022 · Proteins are polypeptide structures consisting of one or more long chains of amino acid residues. Nutritionally, amino acids are divided into 3 groups—essential, nonessential, and semi Amino acid - Building Blocks, Structure, Functions: One of the most useful manners by which to classify the standard (or common) amino acids is based on the polarity (that is, the distribution of electric charge) of the R group (e. They are composed of C, H, O, N and S atoms. Proteins may be divided into two major classes on the basis of their behavior when reacted with water. Plant proteins are a little different. 1. Group I amino acids are glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, and tryptophan. Amino acids are organic compounds that contain amine, carboxyl, and side chain groups. Jul 31, 2021 · Three of the amino acids listed in Table 25-1 (cysteine, cystine, and methionine) contain sulfur in − SH, − S − S −, and − SCH 3 groups. 4)? Loading Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. - There are about 300 amino acids occur in nature. They are organic compounds having two functional groups; one acidic carboxylic (-COOH) group and the other basic amino (-NH 2) group. Other amino acids are polar and are generally referred to as ---. be/P_vXUXZrFKINitrogen balance https://youtu. IUPAC Name: (2S)-2-Amino-3-methylbutanoic acid Symbol: Three-letter code - Val. Amino acid classification. So, amino acids are involved in many important roles in your body. Characteristics of amino Oct 22, 2023 · The amino group attached to the Fourth carbon (numbering from the Carboxyl group) of the amino acid is called “γ-amino acid”. Classification of amino acids Jan 20, 2022 · Amino acids can be classified into 5 types [1-6, 13, 10] a. Each amino acid has unique characteristics arising from the size, shape, solubility, and ionization properties of its R group. Jan 21, 2019 · There are many types of essential amino acids, including: Lysine. All amino acids contain a primary amine group and a carboxylic acid group The classification of amino acids goes beyond textbook learning. In the case of conjugated proteins other organic and/or inorganic substances are obtained. These amino acids are polar in nature but possess a neutral pH value. 25. Every amino acid also has another atom or group of atoms bonded to the alpha carbon known What are amino acids? Amino acids are the building blocks of proteins, i. Amino acids with uncharged polar side chains. . Glutamic acid. Here is the type of amino acids. Classification of Amino Acids Based on Chemical Jan 17, 2023 · All organisms have different essential amino acids based on their physiology. Classification based on the Position of Primary Amino Group. You should be able to classify all the amino acids by polarity, charge, aliphatic vs aromatic, and probably learn the structures and functional groups of the special amino acids (for example: two cysteines close in space may form disulfide bridges under oxidizing conditions, prolines tend to introduce kinks in polypeptides and are often found Learn how amino acids are composed of a carbon, a hydrogen, a carboxyl group, an amino group, and a variable group. Each amino acid has the same core structure, which consists of a central carbon atom, also known as the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and a hydrogen atom. Especially the hydrophobicity of amino acids is often used for structural prediction or for the detection of membrane associated or embedded β-sheets and α-helices. Amino acids are the building blocks or serve as monomers of protein. Mar 29, 2017 · We show that the structure-based classification is strongly supported by amino acid and also nucleotide sequence similarities, suggesting that the similarities are due to common descent. g. One-letter code - V May 13, 2021 · Classification based on composition. Amino acids are depicted by the one-letter code. 5. Histidine is an amino acid that is involved in digestion processes that take place mostly in the stomach. 7: Peptides and Proteins. The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. - They are generally identical on the first 4 items on that list. Amino acids can be either polar or non-polar based on their --- 2. Other amino acids are polar and are generally referred to as ---, To see amino acids on a developed Protein - Structure, Function, Amino Acids: Despite its weaknesses, a functional classification is used here in order to demonstrate, whenever possible, the correlation between the structure and function of a protein. Mar 25, 2017 · Classification of amino acids. Every amino acid also has another atom or group of atoms bonded to the alpha carbon known 1 of 11. The basic 20 amino acids are genetically coded and about 300 amino acids exist due to slight modification of these amino acids. Short range forces happen when the centers of the molecules are separated by three angstroms (10 -8 cm) or less. Nov 28, 2020 · Amino acids are group of organic compound containing carbon, hydrogen, oxygen, and nitrogen. Proteins are the polymers of amino acids, with each amino acid residue joined by a specific type Amino acids and proteins questions. Several amino acids have special properties which appear in specific types of Jun 16, 2015 · About 500 amino acids are known and can be classified in many ways. E. In the aqueous environment of the cell, the both the amino group and the carboxyl Jan 19, 2023 · Amino acids are classified into three groups: ESSENTIAL AMINO ACIDS. Essential amino acids cannot be made by the body. Most are non-protein amino acids. Intermolecular forces are the attractive or repulsive forces between molecules. Essential Amino Acids Mnemonics. L-amino acids are the monomer units that make up the polypeptide chains of proteins. There are 20 different amino acids. Click the card to flip 👆. Ø Based on the core structure of an amino acid (location of NH2 group) the amino acids can be classified as: Ø α-Amino Acid: The primary amino group is attached to the α-carbon atom. Jun 19, 2014 · 23. Simulations - Discover a new way of learning Physics using Real World Simulations. Based on the composition of the ‘R’ side chain, amino acids can be categorized into 8 types: (Fairly Aug 7, 2023 · Phenylalanine combined with the nonessential amino acid tyrosine: 25 mg; Threonine: 15 mg; Tryptophan: 4 mg; Your body forms thousands of different types of protein — all crucial to your Amino acid structure. Mar 10, 2021 · مرحبا أصدقائي في فيديو جديد من قناة تعلم بالعربي , اليوم سنبدأ بالفصل الثاني من الكيمياء الحيوية إذ سنتعرف Jan 1, 2010 · Download Citation | Amino Acids: Chemistry and Classification | Amino acids are the monomers from which proteins are made. We will cover the following:00:00 INTR Sep 26, 2019 · Amino acids that fall under the classification of hydrophobic are alanine, valine, isoleucine, leucine, methionine, phenylalanine, tryptophan and tyrosine. Each amino acids’ structure, name, 1 letter code, 3 letter abbreviation, and class should be memorized. . Through repeated binary separation at the corresponding median of five features F(i) the amino acids are separated into unique groups. There are 20 common amino acids. Sep 17, 2021 · This classification of amino acids has little to do with the structure of amino acids. Classification based on the position of-NH 2: Jan 24, 2024 · Amino acids are organic compounds that consist of a carbon atom attached to a carboxyl group, a hydrogen atom, an amino group, and a variable R group (side chain). pf jm la al uc zo zv jn cv mk