Amino Acids, Proteins, and Enzymes PDF

AMINO ACIDS, PROTEINS, AND ENZYMES Erin Jillian Inciong, Keisha Jovel Malaluan Group 3  AMINO ACIDS Amino acid are the organic compounds that combine to form proteins, hence they are referred to as building components of proteins. These biomolecules ar...

AMINO ACIDS, PROTEINS, AND ENZYMES Erin Jillian Inciong, Keisha Jovel Malaluan Group 3  AMINO ACIDS Amino acid are the organic compounds that combine to form proteins, hence they are referred to as building components of proteins. These biomolecules are involved in several biological and chemical functions in the human body and are the necessary ingredients for the growth and development of human beings. There are about 300 amino acids that occur in nature. Amino acids are the building blocks of proteins. The key elements of amino acids are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). GENERAL STRUCTURE OF AMINO ACIDS The general formula of an amino acid is R-CH(NH2)-COOH. An amino acid is an organic molecule that made up of a basic amino group (-NH2), an acidic carboxyl group (-COOH), and an organic R group (or side chain) that is unique to each amino acid. The term amino acid is short for a-amino (alpha -amino) carboxylic acid.  AMINO ACIDS ARE CLASSIFIED INTO THREE GROUPS: ESSENTIAL - cannot be made by the body. As a result, they must come from food. NON-ESSENTIAL - means that our bodies can produce the amino acid, even if we do not get it from the food we eat. CONDITIONALLY ESSENTIAL - are usually not essential, except in times of illness and stress.  ACID-BASE PROPERTIES ISOELECTRIC POINTS AND ZWITTERIONS Each amino acid has a particular pH called the isoelectric point at which the overall charge on an amino acid molecule is zero. Examples of isoelectric points the carboxyl group has donated a proton to the amino group which from positive NH3+ ion. Zwitterion - A zwitterion is a molecule with functional groups, of which at least one has a positive and one has a negative electrical charge. Amino acids are the best-known examples of zwitterions. AMINO ACIDS AS BASES In strongly acidic conditions a positive ion forms: an amino acid behaves as a base the (COO-) ion gains a proton. AMINO ACIDS AS ACIDS In strongly alkaline conditions a negative ion forms: an amino acid behaves as an acid the (NH3+) ion loses a proton. PHYSICAL PROPERTIES OF AMINO ACIDS Amino acid are colorless, crystalline solid All amino acid have a high melting point Solubility: They are soluble in water, slightly soluble in alcohol, and dissolve with difficulty in methanol,, ethanol and propanol. On heating to high temperatures they decompose All amino acid (except glycine) are optically active Peptide bond  SOURCES OF AMINO ACIDS Amino acids play an important role in performing several biological and chemical functions in different parts of our body, including building and repairing the tissues, the formation and functions of enzymes, food digestion, the transportation of molecules, etc. Our body can synthesize only certain amino acids and the rest of the amino acids which are called essential amino acids should be supplied through protein-rich foods in our daily diet.  DEFICIENCY OF AMINO ACIDS As mentioned above, amino acids are the building blocks of proteins and proteins play a fundamental role in almost all life processes. The deficiency of amino acids may include different pathological disorders, including: Edema. Anemia. Fat deposit in the liver. Insomnia. Skin and hair related problems. Diarrhea. Headache, weakness, irritability, and fatigue. Depression. Hypoglycemia. Loss of Appetite.  PROTEINS Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins are one of the most abundant organic molecules that perform diverse functions in living organisms. They act as structural components, catalysts, hormones, enzymes, and regulators of cellular processes. Proteins are also involved in DNA replication, molecule transport, catalyzing metabolic reactions, and providing structural support to cells. ➤ Made up of chains of amino acids; classified by number of amino acids in a chain Peptides: fewer than 50 amino acids Oligopeptides: 2 to 20 amino acids Dipeptides: 2 amino acids Tripeptides: 3 amino acids Polypeptides: more than 50 amino acids Proteins: more than 50 amino acids, Typically 100 to 10,000 amino acids linked together ➤ These amino acids are bonded together by peptide bonds, forming long protein chains. Peptide Bonds - Amino acids are linked together in proteins by a special kind of bond, the peptide bond ➤ Edman Degradation developed by Pehr Edman, is a method of sequencing amino acids in a peptide AMINO ACIDS THAT MAKE UP PROTEINS PROTEOLYSIS breaks down proteins and peptides into smaller peptides or amino acids.  GENERAL STRUCTURE The chemical formula of proteins is generally represented as RCH(NH2)COOH, where C is carbon, H is hydrogen, N is nitrogen, O is oxygen, and R is a variable side chain group beta-pleated sheet a-helix Linear sequence Local folding patterns Assembly of multiple of amino acids stabilized by hydrogen bonds. 3D folding of the protein polypeptide chains PROTEIN FOLDING AND MISFOLDING Protein folding is the process by which a protein's linear chain of amino acids folds into a three-dimensional structure that allows it to function. Chaperone - assists others to fold properly during and after synthesis. Denaturation and renaturation are processes related to protein structure: MISFOLDING DENATURATION RENATURATION occurs when In proteins, Misfolding is also a factor in proteins lose their renaturation is the other neurodegenerative folded structure reconstruction of the diseases, including Parkinson's, and are no longer native biomolecular Huntington's, Alzheimer's, and able to function structure after denaturation. Creutzfeldt-Jakob disease properly.  PROTEIN-PROTEIN INTERACTIONS (PPI) refers to the physical contact established between two or more protein molecules, where they bind to each other through specific interactions. NON-COVALENT INTERACTIONS COVALENT INTERACTIONS weak chemical a strong chemical bond formed by the bonds that play a sharing of electrons, key role in is established protein structure between specific amino acid residues and function. on each protein PROTEIN APPLICATIONS Medicine and Healthcare Many proteins, such as insulin (for diabetes) and monoclonal antibodies (for cancer treatment or viral infections), are used in drug formulations to treat diseases. Food Industry Proteins such as casein, whey, and soy protein are widely used in food products like dairy alternatives, protein bars, and meat substitutes. Agriculture: Proteins are essential for plant growth, and providing soil microbes with protein- rich plant food can help plants produce their own proteins.Personal Care Proteins like keratin are used in shampoos and conditioners to strengthen hair. Collagen and elastin proteins are used in creams and lotions to promote skin health and reduce aging signs.  ENZYMES Enzymes are biocatalysts present in cells that speed up biochemical reactions without getting itself destroyed in the reaction. All types of biochemical reactions in the cell require enzymes. Enzymes are typically proteins. Certain types of RNA can also serve as catalysts. These RNA molecules are called ribozymes and DNAzymes STRUCTURE OF ENZYMES ANOTHER DESCRIPTION The linear sequence of amino acids that defines the enzyme’s function. Folding patterns like a-helixes and B- sheets that provide structural stability. The 3D folding of the enzyme, which is crucial a substrate binding and catalysis. The organization of multiple polypeptide chains into a functional enzyme complex (e.g., hemoglobin, multi-subunit enzymes).  ACTIVE SITE The region where the substrate binds and the catalytic activity occurs. Enzyme specificity and the role of amino acid residues in the active site.  ENZYME MECHANISM OF ACTION Substrate Binding How substrates interact with the enzyme’s active site (lock-and-key model vs. induced fit model). LOCK-AND-KEY MODEL INDUCED FIT MODEL how enzymes interact with their substrates to facilitate the shape (conformation) of the active site within enzymes is chemical reactions malleable and can be induced to fit the substrate  ENZYME CATALYSIS It speeds up the rate of a specific chemical reaction in the cell. The enzyme is not destroyed during the reaction and is used over and over. Transition State Stabilization How enzymes stabilize the transition state of a reaction, facilitating the conversion of substrates to products.  INDUSTRIAL AND BIOTECHNOLOGICAL APPLICATIONS OF ENZYMES Biocatalysis - The use of enzymes to catalyze organic reactions in the synthesis of pharmaceuticals, fine chemicals, and biofuel. (e.g., Penicillin G, Thermolysin) Enzyme-Linked Immunosorbent Assay (ELISA) - Enzyme-based detection method used in diagnostics and research. Enzyme in Food Industry - Use of enzymes in the production of food and beverages (e.g., proteases in meat tenderization, amylases in brewing) Enzyme in Waste Management - Enzyme-mediated remediation directly or indirectly degrades pollutants by modifying the chemical and physical properties of waste. ENZYME INHIBITORS AND DRUGS Inhibitors as Drug Targets: How enzyme inhibitors are used to treat diseases (e.g., protease inhibitors in HIV treatment). Types of Inhibitors: THREE TYPES OF REVERSIBLE INHIBITION A reversible enzyme inhibitor is a molecule that binds reversibly to the enzyme and slows down or inhibits, the reaction rate. COMPETITIVE INHIBITORS A molecule other than the substrate binds to the enzyme’s active site, causing competitive inhibition. NON-COMPETITIVE INHIBITORS A chemical binds to a location other than the active site in non-competitive inhibition (an allosteric site). UNCOMPETITIVE INHIBITORS The inhibitor binds only to the substrate-enzyme complex in uncompetitive inhibition. ALLOSTERIC INHIBITORS The binding of a regulatory molecule to a separate (allosteric) site turning the enzyme off by changing the shape of the enzyme’s active site.