University:
Liberty University
Course:
BIOM 500 | Introduction to Biomedical Sciences
Academic year:

2024
Views:

91

Pages:

7
Author:

Sheha A.

**Essential Amino Acids** These amino acids cannot be synthesized by adults and must be obtained through diet. **Non-Essential Amino Acids** These amino acids can be synthesized in the body and do not need to be supplied in the diet. **Examples of Essential Amino Acids:** * Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine **Examples of Non-Essential Amino Acids:** * Alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine **Proteins** Proteins are polymers of alpha amino acids which are bonded by peptide bonds. **Classification of Proteins** Protein can be classified on the basis of their composition, shape, and function. **Based on the Composition of Protein:** There are three groups of protein: 1. **Simple Protein:** * They contain only one type of amino acid. * They do not contain any additional groups or elements. * Examples: albumin, serum globulin (except immunoglobulins), keratin, etc. 2. **Conjugated Protein:** * These contain additional non-amino acid groups along with amino acids. **Derived Proteins:** These are the partial hydrolyzed products of simple compound proteins. Examples: * Peptones derived from proteins * Proteoses derived from peptones * Albumin derived from the shape **Classification based on the shape:** There are 2 groups: 1. **Globular Proteins:** They are spherical or oval in shape. * Examples: Hemoglobin, albumin, and enzymes 2. **Fibrous Proteins:** These are elongated and fiber-like structure. * Examples: Keratin, collagen, and elastin **Based on the biological function:** Proteins have diverse functions based on which they are classified as: 1. **Catalytic Proteins:** * All enzymes are proteins in nature (exception is Ribozyme which is RNA in nature). * Examples: Hexokinase, Amylase, etc. **Define protein** 1. Antibodies 2. Structural proteins (hair and nail, collagen) 3. Hormonal proteins 4. Contractile proteins 5. Transport proteins 6. Storage proteins 7. Receptor proteins 8. Membrane proteins **Antibodies** * Immunoglobulins are proteins in nature. * E.g., IgG, IgM, IgA, IgE, IgD **Structural Proteins** * Keratin present in hair and nail, collagen present in muscles. **Hormonal Proteins** * Some hormones are protein in nature. * E.g., Insulin, growth hormone, etc. **Contractile Proteins** * Actin and myosin present in muscle. **Transport Proteins** * E.g., Serum albumin, casein, hemoglobin, fatty acid transport protein **Storage Proteins** * E.g., Ferritin: Storage of iron in liver and spleen **Receptor Proteins** * Rhodopsin present in the retina of the eye * Insulin receptor **Membrane Proteins** * Sodium potassium pump and sodium potassium ATPase