Water is an essential component of all living organisms, making up about 60-70% of the human body and a significant portion of plant and animal cells. It plays a crucial role in biochemical reactions, transportation, temperature regulation, and overall survival. Without water, life as we know it would not exist. From providing a medium for chemical reactions to helping transport nutrients and waste, water is involved in nearly every biological function. Let’s study the vital functions of water in living organisms in detail.
Meaning of Water in Living Organisms
Water is a vital inorganic compound that serves as the most abundant substance in all living organisms. It is essential for maintaining life processes, as it acts as a solvent, medium for chemical reactions, and a transport agent. Without water, biological systems cannot function effectively, making it fundamental to the survival of plants, animals, and humans.
READ ALSO – Characteristics Of Living Things, Meaning And Examples
Functions of Water in Living Organisms
Below are the different functions of water in living organisms with their examples:
1. Acts as a Universal Solvent
- Water dissolves many substances, including salts, sugars, proteins, and gases, making it essential for metabolic reactions.
- It allows cells to absorb nutrients and remove waste efficiently.
Example: In the human body, blood plasma (which is mostly water) dissolves and transports glucose, oxygen, and minerals.
2. Facilitates Chemical Reactions
- Many biochemical reactions, including digestion and cellular respiration, occur in a watery environment.
- Water participates directly in reactions like hydrolysis, where it breaks down large molecules into smaller ones.
Example: During digestion, water helps break down food into simpler molecules that cells can absorb.
3. Regulates Body Temperature
- Water has a high heat capacity, meaning it absorbs and releases heat slowly, helping organisms maintain a stable temperature.
- In humans, sweating helps cool the body by evaporating water from the skin.
Example: On a hot day, the body sweats, and as the sweat evaporates, it cools the skin.
4. Serves as a Transport Medium
- Water is essential for transporting nutrients, gases, and waste in living organisms.
- In animals, blood (which is mostly water) carries oxygen, glucose, and hormones to cells.
- In plants, water transports minerals and nutrients from the roots to the leaves.
Example: In plants, xylem transports water and minerals from the roots to the leaves.
5. Provides Structural Support
- In plants, water maintains turgor pressure, which keeps cells firm and supports stems and leaves.
- In animals, water is a major component of cells and bodily fluids, maintaining shape and function.
Example: A well-watered plant stands upright, but a dehydrated plant wilts due to lack of water pressure.
6. Lubricates and Cushions Joints and Organs
- Water acts as a lubricant in joints, reducing friction and preventing damage.
- It also cushions vital organs like the brain, spinal cord, and eyes, protecting them from injury.
Example: Synovial fluid in joints reduces friction between bones during movement.
7. Aids in Waste Removal and Detoxification
- Water helps remove waste products through urine, sweat, and exhalation.
- It flushes out toxins and prevents the buildup of harmful substances.
Example: The kidneys filter waste from the blood and remove it through urine, which is mostly water.
8. Supports Photosynthesis in Plants
- In plants, water is crucial for photosynthesis, the process by which plants make their own food using sunlight.
- Water provides hydrogen atoms necessary for producing glucose.
Example: Without water, plants cannot photosynthesize and will eventually die.
9. Enables Reproduction in Some Organisms
- Many aquatic organisms release eggs and sperm into water for fertilization.
- Water also helps in the movement of reproductive cells in some animals and plants.
Example: Amphibians like frogs lay their eggs in water, where fertilization takes place.
10. Helps Maintain pH Balance
- Water helps regulate the acid-base balance in organisms, preventing drastic pH changes.
- This is essential for proper enzyme function and metabolism.
Example: Blood maintains a stable pH around 7.4 due to water’s buffering ability.
Conclusion On the Functions of Water in Living Organisms
Water is essential for all living organisms, supporting life at the cellular and system levels. From chemical reactions and temperature regulation to transport and waste removal, water plays a vital role in maintaining life. Without it, biological processes would not function properly, leading to dehydration and death.
Revision Questions and Answers
1. Why is water considered a universal solvent?
Answer: Water dissolves many substances, including salts, sugars, and gases, allowing biochemical reactions to take place.
2. How does water help regulate body temperature?
Answer: Water has a high heat capacity, and in humans, sweating helps cool the body as water evaporates from the skin.
3. What role does water play in photosynthesis?
Answer: Water provides hydrogen atoms needed to produce glucose and releases oxygen as a byproduct.
4. How does water aid in waste removal?
Answer: Water helps flush out waste through urine, sweat, and exhalation, preventing toxin buildup.
5. Why do plants wilt when they lack water?
Answer: Without enough water, plants lose turgor pressure, causing their cells to shrink and the plant to wilt.