Biology Foundations: Life, Chemistry, and Cells

This set of vocabulary flashcards covers introductory biology concepts including the properties of life, levels of biological organization, basic chemistry, and cell structure and function.

Properties of Life

Key characteristics of living organisms, including being organized, acquiring materials and energy, maintaining an internal environment, responding to stimuli, reproducing, developing, and adapting to their environment.

Levels of Life

The biological hierarchy from smallest to largest: atoms, molecules, cells, tissues, organs, organ systems, organism, population, species, community, ecosystem, and biosphere.

Scientific Method

A process involving making observations, constructing a hypothesis, making a prediction, testing with an experiment, analyzing data for a conclusion, and ultimately constructing a scientific theory.

Double Blind Study

An experimental procedure where neither the person being tested nor the technician is aware of the specific treatment being administered.

Evolution

The process in which populations change over time to adapt to their environment and pass on these changes to the next generation.

Element

A substance that cannot be broken down into other substances by ordinary chemical means.

Atoms

Tiny particles that make up elements.

Compound

A molecule that contains atoms of more than one element.

Electrons

Subatomic particles that possess a negative charge.

Protons

Subatomic particles that possess a positive charge.

Neutrons

Subatomic particles that have no electrical charge.

Common Biological Elements

The four elements found in high abundance within living organisms: carbon, nitrogen, hydrogen, and oxygen.

Ion

An atom that has an electrical charge.

Ionic Bond

A bond formed when two atoms are held together by the attraction between opposite charges, such as the reaction between sodium and chlorine atoms.

Polar Covalent Bond

A bond formed when two atoms share electrons unequally due to a difference in their electronegativities.

Non-polar Covalent Bond

A bond formed when two atoms share electrons equally, resulting in no charge separation between them.

Hydrogen Bond

A type of attraction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom such as oxygen, nitrogen, or fluorine.

pH Scale

A mathematical way of indicating the number of hydrogen ions in a solution.

Acidic

A solution with a pH value below $7$.

Basic

A solution with a pH value above $7$. Only a pH of $7$ is considered neutral.

Macromolecules of Life

The four primary large molecules: proteins, carbohydrates, lipids, and nucleic acids.

Monomers of Life

Simple units that form macromolecules, including amino acids for proteins, monosaccharides for carbohydrates, fatty acids and glycerol for lipids, and nucleotides for nucleic acids.

Cell

The fundamental unit of life.

Prokaryote

A microorganism, such as bacteria or archaea, whose usually single cell lacks a nucleus or other membrane-bound organelles and first appeared approximately $3.5$ billion years ago.

Eukaryote

Complex organisms, including animals, plants, fungi, and seaweeds, whose cells contain a membrane-bound nucleus and organelles, appearing between $2$ and $1.4$ billion years ago.

Plant-Specific Organelles

Structures found in plant cells but not animal cells, including chloroplasts, cell walls, amyloplasts, and a large central vacuole.

Animal-Specific Organelles

Structures such as lysosomes and centrioles that are found in animal cells but not in plant cells.

Nucleus

The organelle responsible for storing and protecting the cell's genetic material (DNA) and regulating gene expression.

Ribosomes

The cell's protein-making machinery that links amino acids together in the order specified by messenger RNA.

Smooth ER

Organelle involved in the synthesis and storage of lipids, such as cholesterol and phospholipids, and the detoxification of harmful substances.

Rough ER

Organelle primarily responsible for the synthesis and processing of proteins.

Lysosome

A membrane-bound organelle containing digestive enzymes for breaking down worn-out cell parts or destroying invading viruses and bacteria.

Mitochondria

The powerhouse of the cell that generates chemical energy (ATP) through aerobic respiration.

Chloroplast

Organelle that converts sunlight into chemical energy through photosynthesis, producing oxygen and sugars.

Flagella

Long structures that enable cell movement through liquids by spinning or beating.

Cilia

Small structures used for moving fluids across cell surfaces, sensing the environment, and cell signaling.

Cell Wall

A structure that provides support, shape, and protection while helping the cell withstand osmotic pressure and mechanical stress.

Cytoskeleton

A network that provides structural support, maintains cell shape, and facilitates movement and division.

Vacuole

An organelle used for storing water, nutrients, and waste products while maintaining turgor pressure to support cell structure.