Elements of Life
Elements of Life
The following points will guide you in understanding the elements of life – the primary constituents that make up living things, and their interaction.
Essential Elements
- Life on Earth is based primarily on certain elements. Carbon, Hydrogen, Oxygen, and Nitrogen make up 96% of living matter.
- The remaining 4% includes Phosphorus, Sulphur, Calcium, and Potassium.
Properties of Life’s Elements
- Carbon is key because it has the ability to form large, complex, and diverse molecular structures.
- Hydrogen and Oxygen, apart from their own roles, are fundamental components of water – a crucial element of life.
- Nitrogen is a critical component of proteins and nucleic acids (DNA and RNA).
- Phosphorus is necessary for ATP (adenosine triphosphate), the power source of cells, and nucleic acids.
- Sulphur is a component of some proteins.
- The mineral ions like Potassium and Calcium play many roles like nerve impulse transmission and muscle contraction.
Biochemical Cycles
- Elements are continuously recycled in ecosystems through various biochemical cycles: carbon cycle, nitrogen cycle, oxygen cycle, etc.
- The carbon cycle, for example, includes processes like photosynthesis and respiration that transfer carbon between organisms and the atmosphere.
- Elements are transferred between different parts of the ecosystem: the atmosphere, hydrosphere, lithosphere, and biosphere.
Trace Elements
- Trace elements are those required by an organism in only minute quantities.
- Even though they are needed in small amounts, trace elements are still critical for life. For instance, Iron is necessary for oxygen transport in blood cells.
- Other important trace elements include Iodine, required for thyroid function, and Fluorine, required for healthy teeth.
Organic Compounds
- Life’s essential elements combine to form a vast array of molecules, but the primary types found in living organisms are carbohydrates, lipids, proteins, and nucleic acids.
- These organic compounds are large complex molecules with diverse structures and functions, all composed primarily of carbon atoms.
Chemical Bonds
- Understanding how atoms of these elements combine to form molecules requires some understanding of chemical bonds.
- Covalent bonds, which involve sharing of electrons, are very common in biological molecules. These provide stability important for maintaining the structure of compound.
- A special type of covalent bond, the hydrogen bond, plays a vital role in the structure of proteins and nucleic acids.
Remember that understanding the elements of life and how they interact forms a foundation for many other topics in biology.