Cell Biology: Macromolecules of the Cell - PDF

Macromolecules of the Cell Prince E. Adjei Kwame Nkrumah University of Science and Technology Topic: Macromolecules of the Cell Module 0: Introduction to Cell Biology Cell Biology (BME 161) © 2024 Prince E. Adjei  MACROMOLECULES Topic...

Macromolecules of the Cell Prince E. Adjei Kwame Nkrumah University of Science and Technology Topic: Macromolecules of the Cell Module 0: Introduction to Cell Biology Cell Biology (BME 161) © 2024 Prince E. Adjei  MACROMOLECULES Topics: (1). Biomolecular Types and Functions (2). Structure-Function Relationships (3). Bioinformatics tools  Learning Objectives Define the structure and biological roles of proteins, nucleic acids, lipids, and carbohydrates. Explain the types of interactions with chemical bonds that stabilize biomolecular structures. Relate the structural features of each biomolecule to its specific functions in biological systems. Explore bioinformatics tools for analyzing the structure and function of macromolecules. Compare the roles of different biomolecules in enabling cellular processes.  Review There are several bonds in biological systems. They include: Covalent bonds, Ionic bonds, Hydrogen bonds, and Vander Waal forces.  MACROMOLECULES? In biology, macromolecules refer to large organic molecules that form by polymerization, a process that joins smaller units called monomers via covalent bonds. These biological macromolecules are essential for life and include proteins, nucleic acids, carbohydrates and lipids.  Proteins Proteins are macromolecules composed of amino acid subunits covalently attached to form long linear chains called polypeptides. These chains fold into specific three-dimensional shapes, which may function independently or combine with additional polypeptide chains or non-polypeptide groups, such as a heme molecule, to form the final functional protein structure.  Structure of Proteins Diverse shapes and molecular weights of proteins are determined by the specific amino acid sequence. This sequence dictates folding, defining the protein's structure and function. Protein shape is essential for its function, and small changes can cause dysfunction. Minor alterations in the amino acid sequence may lead to diseases like Huntington's disease and sickle cell anemia.  Types of Protein Structures Globular Proteins: These fold into compact, globe-like shapes. Example: Hemoglobin, which is responsible for oxygen transport in the blood.  Types of Protein Stucures. Fibrous Proteins: These fold into long, extended fiber- like chains. Example: Collagen, which provides structural support in skin and connective tissues.  Functions of Proteins. Proteins perform essential functions throughout the systems of the human body: catalyzing chemical reactions synthesizing and repairing DNA transporting materials across the cell receiving and sending chemical signals responding to stimuli providing structural support  Roles of Proteins Enzymatic Activity: Catalysis :Proteins act as enzymes to accelerate biochemical reactions essential for life, such as digestion and metabolism. Substrate Specificity: The unique shape of an enzyme allows it to bind specific reactants (substrates) at the active site, enabling breakdown, rearrangement, or synthesis.  Roles of Proteins Types of Enzymes: Catabolic Enzymes: Break down substrates (e.g., amylase for carbohydrates, lipase for fats). Anabolic Enzymes: Build complex molecules (e.g., DNA Polymerase for DNA synthesis).  Roles of Proteins Signaling: Proteins play crucial roles in cellular communication by transmitting and amplifying signals, often through pathways involving enzymes. Signaling proteins, such as kinases, modify other proteins or cellular components to regulate processes like growth, immune responses, and metabolism.  Nuclei Acids Nucleic acids - Deoxyribonucleic acid (DNA) and Ribonucleic acid (RNA), are made from monomers known as nucleotides. Each nucleotide has three components: a 5-carbon sugar, a phosphate group, and a nitrogenous base. If the sugar is deoxyribose, the polymer is DNA. If the sugar is ribose, the polymer is RNA. Nuclei Acids  Functions of Nuclei Acids DNA stores hereditary information in the form of a nucleotide sequence. This sequence encodes the instructions for the development, functioning, growth, and reproduction of all living organisms. Some RNA molecules, such as ribozymes, have catalytic functions. RNA can also form structures, such as in the ribosome or spliceosome, aiding in cellular processes.  Carbohydrates Carbohydrates are organic molecules composed of carbon (C), hydrogen (H), and oxygen (O). They play essential structural, energy, and signaling roles in biological systems.  Monosaccharides Also known as simple sugars Basic building blocks of carbohydrates. Examples: Glucose, fructose, galactose. Functions: Quick energy source; precursors for other biomolecules.  Disaccharides Composed of two monosaccharides linked by glycosidic bonds. Examples: Maltose, sucrose, lactose. Functions: Transported forms of carbohydrates in some organisms.  Oligosaccharides Short chains of monosaccharides (2-10 units). Examples: raffinose and stachyose Functions: Play roles in cell recognition and signaling.  Polysaccharides Long chains of monosaccharides. Examples: Storage polysaccharides: Starch (plants), glycogen (animals) Structural polysaccharides: Cellulose (plants), chitin (insects) Functions: Energy storage (starch, glycogen), provide structural support (cellulose in plant cell walls, chitin in exoskeletons). Polysaccharides  Lipids Lipids are a diverse group of molecules that all share the characteristic that at least a portion of them is hydrophobic. Lipids play many roles in cells, including serving as energy storage Types of Lipids Role Of Lipids In Human Body Recommended Materials