Biomoléculas Orgánicas: Monómeros y Polímeros

Introduction to Organic Biomolecules

Overview of Cell Composition

• The video introduces organic biomolecules and reviews monomers and polymers, highlighting that 70-75% of a cell's composition is water.

• The remaining components include large molecules known as macromolecules, which are essential for cellular function.

Types of Macromolecules

• Four key macromolecules are discussed: proteins, nucleic acids, carbohydrates, and lipids.

• Proteins play crucial roles in metabolism, including enzymes that accelerate reactions and antibodies that defend against microorganisms.

Nucleic Acids and Carbohydrates

• Nucleic acids (DNA and RNA) are vital for hereditary information transmission and protein synthesis.

• Carbohydrates provide energy; they can be simple sugars (monosaccharides) or complex forms (polysaccharides like starch and glycogen).

Lipids' Functions

• Lipids serve various functions such as hormones, vitamins, and structural components of cell membranes (e.g., phospholipids).

Structure of Macromolecules

Characteristics of Macromolecules

• Macromolecules are large structures formed from smaller organic molecules called monomers.

Elements Composing Biomolecules

• Carbohydrates and lipids consist mainly of carbon, hydrogen, and oxygen; proteins also contain nitrogen while nucleic acids include phosphorus.

Formation of Polymers

Monomers to Polymers

• Monomers combine through covalent bonds to form larger structures known as polymers.

Polymerization Process

• The process involves the release of water during the fusion of monomers—a reaction termed condensation or dehydration synthesis.

Example Reaction Mechanism

Understanding Polymer Synthesis and Degradation

Polymer Formation through Dehydration

• The process of polymerization involves the joining of two monomers, where one loses a hydrogen atom and the other loses a hydroxyl group (OH), resulting in the formation of water. This reaction is known as dehydration or condensation.

• A polymer can be formed from three monomers through this dehydration process, which releases a molecule of water during synthesis.

Polymer Degradation via Hydrolysis

• To degrade a polymer back into smaller units (monomers), it is necessary to break the bonds between them. This involves adding water to restore lost atoms: one monomer receives an OH group while another gets a hydrogen atom.

• The addition of water to break down polymers is termed hydrolysis, leading to the release of individual monomers from the larger chain.

Key Biomolecules: Carbohydrates

• Carbohydrates are identified as polymers made up of monosaccharides, with monosaccharides being their basic building blocks.

• When two monosaccharides join together, they form a disaccharide; larger structures composed of many monosaccharides are called polysaccharides.

Proteins and Their Building Blocks

• Proteins are polymers formed from amino acids, with only 20 different amino acids existing that combine in various sequences to create all proteins.

• The structure of proteins is crucial for their function; they must fold into specific three-dimensional shapes to operate effectively.

Nucleic Acids Structure and Function

• Nucleic acids like DNA control cellular functions and consist of nucleotides as their monomers. Each nucleotide comprises a nitrogenous base, a five-carbon sugar (deoxyribose), and a phosphate group.

• Unlike carbohydrates, proteins, and nucleic acids that have repetitive units (monomers), lipids do not necessarily follow this pattern; some lipids contain fatty acids while others do not.

Lipids Overview

Overview of Lipids and Their Components

Understanding Triglycerides and Sterols

• Discussion on triglycerides, which will be elaborated in the class about fats.

• Introduction to sterols, described as molecules formed by multiple rings that do not contain fatty acids.

• Mention of cholesterol's role in forming various hormones, including testosterone.

Classification of Lipids

• Clarification that lipids are not strictly considered polymers since they are not made up of monomers.

• Only carbohydrates, proteins, and nucleic acids are classified as true polymers among biological macromolecules.

Summary of Carbohydrates

Monosaccharides and Polysaccharides

• Explanation that monosaccharides are small units that can repetitively form short chains known as oligosaccharides.

• Oligosaccharides can consist of two to five monosaccharide units linked together.

• The polymer counterpart to monosaccharides is polysaccharides, which are large chains like starch derived from plants.

Proteins: Structure and Function

Amino Acids and Peptides

• Identification of amino acids as the monomers for proteins; short chains of amino acids are referred to as oligopeptides.

• Functional proteins require specific folding or conformational changes in their amino acid chains to become active.

Nucleic Acids: Building Blocks