Introduction to Biology and The Chemistry of Life

Biology

The study of life and living things.

Biosphere

The part of earth that sustain life

Organisms

Living things

Atoms and molecules

Are the simplest parts of the living system.

Cell

The smallest unit of life capable of carrying out all the functions of living things.

Tissue

A group of cells performing a specific function in a multicellular organism.

Organ

A group of different tissues that function together for a special purpose.

Organ system

Several organs working together to perform a function.

Population

A group of organisms of the same species that live together in particular location.

Community

All the population of different kinds of organisms living in the same place.

Ecosystem

A community of organisms in an area, as well as the non living factors of the environment.

Anatomy

Physical structure of humans or other animals.

Botany

Structure and function of plants.

Cytology

Structure and function of cells.

Ecology

Relationships among organisms and their environments.

Ethology

Animal behavior.

Genetics

Heredity

Immunology

The body’s defenses against disease and foreign substances.

Microbiology

Microscopic organisms.

Molecular biology

The chemical processes within cells.

Physiology

The functions of organs and organ systems.

Taxonomy

The scientific classification and naming of organisms.

Zoology

The structure and function of animals.

Microscope

Are used to study organisms that are too small to be seen with the unaided eye.

Computers

Have revolutionized the work of biologists by its ability to store and use large amounts of information and analyze data.

Matter

is anything that occupies space and has mass; it is comprised of elements.

Element

One of the basic substances that cannot be broken down further; 98 occur naturally and combine to form molecules.

Atom

Smallest unit of an element that retains its properties; made of protons, neutrons, and electrons.

Proton

Positively charged particle found in the nucleus of an atom.

Neutron

Neutral particle found in the nucleus of an atom.

Electron

Negatively charged particle that orbits around the nucleus of an atom.

Bond

Attractive force that holds atoms together through electron interactions.

Ionic bond

Bond formed when electrons are transferred from one atom to another.

Covalent bond

Bond formed when atoms share electrons.

Hydrogen bond

Weak bond formed between a hydrogen atom and a more electronegative atom.

Van der Waals interactions

Weak attractions between molecules due to temporary charges.

Water

Polar molecule essential for life with unique properties due to hydrogen bonding.

Polarity

Unequal sharing of electrons in a molecule, creating partial charges.

Solvent

Substance that dissolves other molecules; water is an excellent solvent.

Heat capacity

Amount of heat required to raise temperature; water has a high heat capacity.

Heat of vaporization

Energy required to turn liquid water into vapor; important for cooling through sweat evaporation.

Cohesion

Attractive force between water molecules caused by hydrogen bonding.

Surface tension

Effect of cohesion that allows water’s surface to resist force.

Adhesion

Attraction between water and other substances; allows water to climb surfaces.

Capillary action

Movement of water upward in narrow tubes due to adhesion.

pH

Measure of hydrogen ion concentration in a solution.

Acid

Substance that increases hydrogen ion concentration, lowering pH.

Base

Substance that decreases hydrogen ion concentration, raising pH.

Buffer

Substance that stabilizes pH by moderating changes in hydrogen ion concentration.

Homeostasis

Maintenance of stable internal conditions in living organisms, including pH balance.

Carbon

Element central to biological molecules; can form four covalent bonds with other atoms.

Hydrocarbon

Molecule made only of carbon and hydrogen; can form chains or rings.

Functional group

Group of atoms attached to hydrocarbons that give specific properties and functions.

Macromolecule

Large molecule essential for life; includes proteins, carbohydrates, nucleic acids, and lipids.

Monomer

Single unit that serves as the building block of polymers.

Polymer

Large molecule made from monomers; has properties different from its components.

Dehydration reaction

Reaction where monomers join to form polymers by releasing a water molecule.

Hydrolysis reaction

Reaction where polymers break into monomers by adding water.

Protein

Macromolecule that performs many cellular functions such as structure and enzymes.

Carbohydrate

Macromolecule that provides energy and structural support.

Nucleic acid

Macromolecule that stores and transmits genetic information.

Lipid

Macromolecule that provides long-term energy storage and makes up cell membranes.

Osmotic pressure

Pressure related to water movement across membranes; reduced when monomers form polymers, helping maintain cellular balance.