Biology Chapter 1: The Study of Life

Study Notes

Biology is the scientific study of life, encompassing scales from molecules to the entire planet.
Five ways to think about life: Organization, Information, Energy & Matter, Interactions, and Evolution.
Biological organization: ranges from the molecular & cellular level to the global ecosystem level
Emergent properties: characteristics of a system that arise from the interactions of its components.
- Biosphere: all living things on Earth and the places where life exists.
- Ecosystem: all living things in a particular area, along with nonliving components like soil, water, and light.
- Community: all organisms inhabiting a particular ecosystem (e.g., plants, animals, fungi).
- Population: all individuals of a species living in a specific area.
- Organisms: individual living things.
- Tissues: groups of cells performing a specialized function.
- Cells: the fundamental unit of life's structure and function.
- Organelles: functional components within cells.
- Molecules: chemical structures made up of two or more atoms.

Elements: substances that cannot be broken down by chemical reactions.
- The most common elements in life are Carbon, Hydrogen, Oxygen, and Nitrogen (make up 96% of living matter).
Atoms: smallest units of matter.
- Subatomic particles: protons, neutrons, and electrons.
Isotopes: atoms with the same number of protons but different numbers of neutrons.
Compounds: substances formed by the chemical combination of two or more different elements.
Molecules: Groups of atoms bonded together.
Covalent bonds: atoms share electrons.
- Nonpolar covalent bond: electrons shared equally.
- Polar covalent bond: electrons shared unequally, creating partial charges.
Ionic bonds: atoms transfer electrons, creating ions with opposite charges that attract each other.
Hydrogen bonds: attraction between a hydrogen atom with a partial positive charge and another atom with a partial negative charge.