Biological Organization and Biomolecules: Essential Concepts

Levels of Biological Organization

The hierarchy of life progresses from the smallest components to the entire planet: Quark, Atom, Macromolecular, Subcellular, Tissue, Organs, Apparatuses and Systems, Individuals, Populations, Communities, Ecosystems, and Biosphere.

Characteristics of Living Beings

• Chemical Composition: Living things are formed by two or more bioelements.
• Structure: Organisms consist of one or more cells, which serve as the fundamental unit of structure, function, genetics, and evolutionary origin.
• Metabolism: The sum of all vital functions based on chemical reactions, including growth, adaptation, irritability, and homeostasis.

Bioelements and Inorganic Molecules

Living beings utilize 27 bioelements to perform three basic functions: creating structure, catalyzing chemical reactions, and transporting chemicals. Inorganic molecules include:

• Water and Mineral Salts: Electrolytes that dissociate into ions.
• Gases: Soluble in water and involved in photosynthesis and respiration.
• Solid Minerals: Often found as salts forming hard structures like bones.
• Minerals in Solution: Metallic or non-metallic ions that maintain cellular balance.

Organic Biomolecules

Organic compounds are defined by the presence of carbon as a basic element.

1. Carbohydrates

These molecules release energy through oxidation. They are classified as:

• Monosaccharides: Simple sugars with 3 to 10 carbons.
• Oligosaccharides: A union of several monosaccharides.
• Polysaccharides: Complex chains, usually composed of glucose.

Function: Primary fuel for energy metabolism during respiration.

2. Lipids and Fats

Composed of a glycerol molecule and three fatty acids, lipids include neutral fats, steroids, fat-soluble vitamins, and phospholipids. Common types include triglycerides, phosphoglycerides, sphingolipids, and terpenes.

Functions: Structural support, energy reserves, and functional components in hormones.

3. Proteins

Proteins result from the combination of 20 amino acids and are classified as simple or conjugated. Their structure is divided into four levels. Amino acids contain both an amino and a carboxyl functional group.

Key Functions:

• Catalytic: Enzymes that transform other molecules.
• Regulatory: Hormones that act at specific levels.
• Structural: Providing support (e.g., collagen).
• Defensive: Antibodies for protection.
• Transport: Mucoproteins and hemoglobin for carrying substances.
• Signal Transduction: Cellular communication.