Transport

Introduction to Transport in Living Organisms

  • Transport in biology refers to the movement of substances within a cell or between different parts of an organism.
  • These substances include oxygen, carbon dioxide, nutrients, waste products, and water - all crucial for sustaining life.
  • Transport occurs at various levels: within cells (intra-cellular), between cells (inter-cellular), and from one organ to another.

Types of Transport

  • There are different types of transport: passive transport, active transport and bulk transport.
  • Passive transport requires no energy as substances move from an area of high concentration to low concentration. This includes diffusion and osmosis.
  • Active transport requires energy (ATP) as substances are moved against a concentration gradient, i.e., from an area of low concentration to high concentration.
  • Bulk transport involves the transport of large substances or particles across the membrane through the use of vesicles, it includes endocytosis and exocytosis.

The Circulatory System

  • The circulatory system is a significant transport system in higher animals, consisting of the heart, blood vessels, and blood.
  • The heart acts as the pumping organ, maintaining blood circulation throughout the body.
  • Arteries carry oxygen-rich blood away from the heart, veins carry oxygen-depleted blood towards the heart, while capillaries exchange substances with tissues.
  • Blood acts as the medium to transport nutrients, oxygen, carbon dioxide, hormones, and waste products.

The Xylem and Phloem in Plants

  • Plants’ transport system consists of two main types of tissues: xylem and phloem.
  • The xylem transports water and mineral nutrients from the roots to the rest of the plant.
  • The phloem transports organic substances (like glucose produced during photosynthesis) from leaves to other parts.

Importance of Transport in Living Organisms

  • Proper transport is essential for the survival of all organisms: it enables nutrient uptake, waste elimination, and communication between cells.
  • In multicellular organisms, it helps in distribution of hormones and other chemical signals, thus coordinating different functions.
  • In plants, it aids in water balance and supports the plant structure.