Biological Nutrition, Cellular Processes and Reproduction

Biological Nutrition and Cellular Processes

Nutrition is the set of processes by which bodies exchange matter and energy with their environment to maintain internal organization and carry out their vital functions.

Types of Cellular Nutrient Intake

• Intracellular Digestion: The cell engulfs a food particle into the cytoplasm within a vesicle (phagosome). This vacuole fuses with a lysosome containing digestive enzymes to form a digestive vacuole. Nutrients are digested and pass through the cytoplasmic membrane, while waste is expelled.
• Extracellular Digestion: A lysosome fuses with the plasma membrane, releasing enzymes outside the cell. These enzymes break down large food molecules into smaller fragments that can penetrate the plasma membrane and enter the cytoplasm.

Cellular Transport Mechanisms

• Endocytosis: Material is incorporated into the cell as the membrane invaginates, creating a vesicle that encloses the substance. The vesicle detaches into the cytoplasm, reducing the overall membrane surface.
• Phagocytosis: The process of introducing large solid particles into the cell.
• Pinocytosis: The process of entering small liquids with dissolved molecules.
• Osmosis: The movement of water between two areas of different concentrations separated by a semipermeable membrane.

Metabolism and Biological Functions

Anabolism is the set of processes that lead to the synthesis of complex molecules, requiring the incorporation of energy.

Relationship and Reproduction

Relationship: These processes enable the body to recognize environmental changes and respond adequately to them.

Reproduction: This function allows living things to produce individuals with the same characteristics, thereby perpetuating the species.

Meiosis

Meiosis is a process of nuclear division consisting of two consecutive cell divisions with DNA replication between them. The stages include: prophase, metaphase, anaphase, and telophase.