Fundamentals of Biology: Molecules, Cells, and Life

The global average temperature is approximately 15°C. Earth's water exists in a liquid state or is stored as ice at the poles. The atmosphere is an essential factor for life. Key biological concepts include:

The Biosphere and Bioelements

• The Biosphere: The region of the Earth where life exists.
• Bioelements: Chemical elements that constitute living beings.

Molecular Composition of Life

• Vitamins: A group of organic molecules with a variable chemical nature.
• Inorganic Molecules: Water is the major component of living organisms, varying between 70% and 90% by weight. Mineral salts are involved in fundamental processes such as muscle contraction.
• Organic Molecules: Sugars and carbohydrates provide energy. Glucose and fructose join together to form lactose. Proteins, composed of amino acid chains, are responsible for forming structures. Other components include fats, lipids, and nucleic acids.

Cellular Biology

• Prokaryotic Cells: These cells have genetic material that is free in the cytoplasm and lack membrane-bound organelles.
• Eukaryotic Cells: These cells possess genetic material surrounded by a membrane, with subcellular organelles also coated in membranes.