1.1.1 - Prokaryotes and eukaryotes

Cell theory

Describes that cells are the basic structural unit of all living organisms.

Prokaryotic cell

A cell that does not contain a nucleus or other membrane-bound organelles; considered the oldest living form on earth.

Eukaryotic cell

A cell that has membrane-bound organelles and is surrounded by a plasma membrane; DNA is contained in the nucleus.

Endosymbiosis

The theory that eukaryotic cells evolved when a prokaryotic bacterial cell entered and became incorporated into a larger cell.

Surface area to volume ratio

An important factor in the limitations of cell size, affecting the need for internal compartments with specific cellular functions.

Chloroplast

An organelle in plant cells that is responsible for photosynthesis.

Mitochondria

Organelles that produce energy for the cell through cellular respiration.

Plasma membrane

A semi-permeable barrier surrounding the cell that regulates the passage of substances.

Unicellular

An organism consisting of a single cell.

Multicellular

An organism consisting of many cells.

Cytoplasm

The substance within a cell, excluding the nucleus.

Cytosol

The aqueous component of the cytoplasm in which cell organelles are suspended.

Ribosomes

Molecular machines responsible for protein synthesis in cells.

Flagellum

A whip-like structure that enables movement in some cells.

Homeostasis

The ability of a cell or organism to maintain stable internal conditions.

Microscope

An instrument used to see objects that are too small for the naked eye.