El METABOLISMO de los seres vivos [ANABOLISMO y CATABOLISMO]

Metabolism of Living Beings

Introduction to Metabolism

• All organisms require continuous energy capture for vital activities and growth, necessitating the incorporation of substances to create living matter.

• Organisms meet these needs through various means: animals consume other beings, while plants harness solar energy and absorb minerals from the soil.

Understanding Metabolism

• The focus of this video is on the metabolism of living beings.

• In animals, food is broken down into smaller substances that are absorbed by the blood and transported with oxygen to cells.

• The true utilization of nutrients occurs through complex chemical reactions known as metabolism.

Role of Enzymes in Metabolism

• Metabolism relies on special substances called biocatalysts or enzymes that accelerate chemical reactions; without them, processes would be too slow for survival.

• Nutrient transformation involves multiple stages controlled by different biocatalysts, forming what are known as metabolic pathways.

Metabolic Pathways

• Each metabolic pathway consists of a series of sequential reactions catalyzed by distinct enzymes, leading to significant changes in substrate molecules.

• If any step in a metabolic pathway is inhibited due to enzyme malfunction or lack of substrate, the entire pathway halts.

Importance of Metabolites

• Each reaction within a pathway contributes to cellular or organismal life functions, allowing precise regulation of metabolic activity.

• Intermediates produced during metabolism are termed metabolites; many systems have unique pathways but share similarities across diverse organisms.

Types of Metabolism

Anabolism vs. Catabolism

• There are two primary types of metabolism:

• Anabolism: Constructive processes that build new living matter.

• Catabolism: Destructive processes that extract energy from assimilated substances.

Anabolic Processes

• Anabolic processes synthesize all substances constituting an organism's matter through various chemical reactions involving assimilated nutrients.

• These transformations lead to new compounds that are often more complex and varied in composition; anabolic activity is intense during growth phases.

Energy Storage and Muscle Growth

• During physical activity, anabolic reactions help increase muscle mass and strength; when less synthesis is needed, anabolism also creates large energy-storing molecules like starch (in plants) and glycogen (in animals).

Protein Synthesis

Building Blocks of Life

• Proteins consist of smaller molecules called amino acids and serve as fundamental building blocks for living matter.

Biosynthesis Process

• One crucial anabolic process involves protein biosynthesis where ribosomes assemble free amino acids into proteins based on DNA instructions from the nucleus.

Energy Consumption in Anabolic Reactions

Metabolism: Catabolism and Its Role

Understanding Catabolism

• Catabolism is a chemical activity that degrades complex molecules to obtain energy and materials for anabolic reactions, forming a feedback cycle with anabolic pathways.

• Complex molecules can be broken down into smaller ones, releasing the energy that held the original molecule together. This process is essential for energy capture.

• The catabolic reactions transform nutrients into simpler molecules to harness released energy, known as exergonic reactions, which are crucial for various biological activities.

• Released energy from catabolic processes can be used for vital activities like anabolic reactions or simply generating heat within the organism.

The Role of Oxygen in Catabolism

• Catabolism primarily relies on oxidation, where oxygen plays a critical role during respiration by reacting with substances to release energy.

• Oxygen acts similarly to combustion within cells, particularly in mitochondria, burning molecules and releasing stored energy while forming new compounds.

• Oxidized molecules lose their usable energy and are expelled from the cell; thus, oxygen intake is vital for cellular function.

Energy Sources and Utilization

• Simple organisms like protozoa absorb oxygen directly from their environment, while more complex organisms have advanced systems to transport oxygen efficiently throughout their bodies.

• Carbohydrates (especially glucose) are optimal sources of energy due to their high-energy yield upon oxidation. Athletes often consume glucose solutions post-exercise for rapid recovery.

Alternative Processes: Fermentation

• Most organisms require oxygen to oxidize nutrients; however, some microorganisms (e.g., certain bacteria in the digestive system) utilize alternative substances when oxygen is unavailable through fermentation processes.

Importance of Catabolic Reactions

• Catabolic reactions also provide necessary building blocks by simplifying complex structures; proteins consumed in diet are degraded into free amino acids used for synthesizing new proteins.

• Future discussions will cover how these metabolic processes are regulated through enzymatic activity.