Chapter 1

One of the two divisions of prokaryotes, often found in hostile environments such as hot springs or concentrated brine.

One of the two divisions of prokaryotes; some species cause disease. Used to refer to any prokaryotic microorganisim.

The basic unit from which a living organism is made; consists of an aqueous solution of organic molecules enclosed by a membrane.

Specialized organelle in algae and plants that contains chlorophyll and serves as the site in which photosynthesis takes place.

Long, threadlike structure composed of DNA and proteins that carries the genetic information of an organism; becomes visible as a distinct entity when a plant or animal cell prepares to divide.

Contents of a cell that are contained within its plasma membrane but, in case of eukaryotic cells, contained outside the nucleus.

System of protein filaments in the cytoplasm of a eukaryoitc cell that gives the cell shape and capacity for directed movements. It’s most abundant components are actin filaments, microtubules, and intermediate filaments.

Contents of the mail compartment of the cytoplasm, excluding membrane-enclosed organelles such as endoplasmic reticulum and mitochondria. The cell fraction remaining after membranes and other organelles have been removed.

Double-stranded polynucleotide formed from two separate chains of covalently linked deoxyribonucleotide units. Serves as the cell’s store of genetic information that is transmitted from generation to generation.

An organism whose cells have a distinct nucleus and cytoplasm.

Process of gradual modification and adaptation that occurs in living organisms over generations.

The total genetic information carried by all the chromosomes of a cell or organism.

Any organelle in the eukaryotic cell that is surrounded by a lipid bilayer.

Unit of length equal to one millionth (10-6) of a meter or (10-4) centimeter.

Membrane-enclosed organelle, about the size of a bacterium, that carries out oxidative phosphorylation and produces most of the ATP in eukaryotic cells.

A living thing selected for intensive study as a representative of a large group of species.

In Biology, refers to the prominent, rounded structure that contains the DNA of a eukaryotic cell. In chemistry, refers to the dense, positively charged center of an atom.

A discrete structure of subcompartment of a eukaryotic cell that is specialized to carry out a particular function.

The process by which plants, algae, and some bacteria use the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide and water.

The protein-containing lipid bilayer that surrounds a living cell.

Polymer built from amino acids that provides cells with their shape and structure and performs most of their activities.

A free-living, nonphotosynthetic, single-celled, motile eukaryote.

Large macromolecular complex, composed of ribosomal RNAs and ribosomal proteins, that translates messenger RNA into protein.

Molecule produced by the transcription of DNA ; usually single-stranded, it is a polynucleotide composed of covalently linded ribonucleotide subunits. Serves a variety of structural, catalytic and regulatory functions in cells.