Amino-Acids-Peptides-and-Proteins-Structure-and-Classification.pptx

This presentation will explore the fundamental building blocks of life, focusing on the structure, properties, and classification of amino acids, peptides, and proteins. Understanding these molecules is crucial for comprehending the complexity and functionality of biological systems.
Amino acids are the basic units that make up proteins. Each amino acid has a central carbon atom bound to an amino group, a carboxyl group, a hydrogen atom, and a unique side chain (R group). The R group determines the amino acid's chemical properties.

1. Amino Acids, Peptides, and Proteins: Structure and Classification This presentation will explore the fundamental building blocks of life, focusing on the structure, properties, and classification of amino acids, peptides, and proteins. Understanding these molecules is crucial for comprehending the complexity and functionality of biological systems. DM by Dr Chithra M

2. Introduction to Amino Acids Amino acids are the basic units that make up proteins. Each amino acid has a central carbon atom bound to an amino group, a carboxyl group, a hydrogen atom, and a unique side chain (R group). The R group determines the amino acid's chemical properties. 1 Essential Amino Acids There are 20 standard amino acids, 9 of which are essential. This means our body cannot synthesize them, and we must obtain them from our diet. 2 Non-Essential Amino Acids The remaining 11 amino acids can be synthesized by the body from other molecules, making them non-essential.

3. Classification of Amino Acids Based on Polarity Amino acids can be classified based on the polarity of their side chains, which influences their interactions with water and other molecules. Non-Polar (Hydrophobic) Non-polar amino acids have hydrophobic side chains, meaning they are repelled by water. They tend to cluster together in the interior of proteins. Glycine Alanine Valine Leucine Isoleucine Methionine Phenylalanine Tryptophan Proline Polar Uncharged Polar uncharged amino acids have hydrophilic side chains, meaning they are attracted to water. They often reside on the surface of proteins, interacting with the aqueous environment. Serine Threonine Asparagine Glutamine Cysteine Polar Charged Polar charged amino acids have side chains that carry a net positive or negative charge. These charged amino acids play important roles in protein structure and function, often interacting with other charged molecules. Lysine Arginine Histidine Aspartic acid Glutamic acid

4. Zwitterions Amino acids exist in a zwitterionic form at physiological pH. This means they carry both a positive and negative charge, but overall, they are electrically neutral. The amino group is protonated (NH3+), and the carboxyl group is deprotonated (COO-). Amino Group Carboxyl Group Protonated (-NH3+) Deprotonated (-COO-)

5. Peptides Peptides are short chains of amino acids linked by peptide bonds. A peptide bond forms when the carboxyl group of one amino acid reacts with the amino group of another, releasing a molecule of water. This process is known as a condensation reaction. Amino Acid 1 Carboxyl Group Amino Acid 2 Amino Group Dipeptide Peptide Bond Water Released

6. Dipeptides A dipeptide consists of two amino acids linked by a single peptide bond. The amino acid on the left-hand side of the peptide bond is called the N-terminal amino acid, while the one on the right-hand side is the C-terminal amino acid. Glycylalanine Glycine is the N-terminal amino acid, and alanine is the C-terminal amino acid. Alanylglycine Alanine is the N-terminal amino acid, and glycine is the C-terminal amino acid.

7. Proteins Proteins are large, complex molecules made up of one or more long chains of amino acids. These chains, known as polypeptides, fold into specific three-dimensional structures, giving proteins their unique properties and functions. 1 Primary Structure The linear sequence of amino acids in a polypeptide chain. 2 Secondary Structure Local folding patterns, such as alpha-helices and beta-sheets, stabilized by hydrogen bonds. 3 Tertiary Structure The overall three-dimensional shape of a single polypeptide chain, determined by interactions between side chains. 4 Quaternary Structure The arrangement of multiple polypeptide chains in a protein complex.

8. Protein Function Proteins perform a vast array of functions in living organisms. These functions include catalysis (enzymes), structural support, transport, communication, and defense. Enzymes Proteins that catalyze (speed up) biochemical reactions. Structural Support Proteins that provide shape and support to cells and tissues. Transport Proteins that move molecules across cell membranes or within the body. Communication Proteins that act as messengers, transmitting signals between cells.

9. Protein Denaturation Denaturation is the process by which a protein loses its normal structure and function. This can occur due to changes in temperature, pH, or the presence of certain chemicals. Denatured proteins are often unable to perform their intended roles. Native Protein Folded into its correct three-dimensional structure. Denatured Protein Unfolded and dysfunctional.

10. Summary Proteins are essential for life, playing a crucial role in almost every biological process. By understanding the structure and classification of amino acids, peptides, and proteins, we gain insights into the complexity and functionality of biological systems. Amino Acids The building blocks of proteins, classified based on polarity. Peptides Short chains of amino acids linked by peptide bonds. Proteins Large, complex molecules with diverse functions, determined by their structure.