Lecture 3: Bacteria and Archaea

These flashcards cover key vocabulary and definitions related to the topics of Bacteria, Archaea, and their roles in ecosystems as discussed in the lecture notes.

Tree of Life

The evolutionary history of life on earth, classified into 3 domains: Bacteria, Archaea, and Eukarya.

Prokaryotes

Single-celled organisms that lack a nucleus, including Bacteria and Archaea.

Euglenozoans

A group of protists that includes the euglenoids and kinetoplastids.

Extremophiles

Organisms that thrive in extreme environments, such as high salinity or temperature.

Stromatolites

Fossilized structures made from sediment layers built up by microbial mats, dating back 3.5 billion years.

Nitrogen-fixation

The process by which certain prokaryotes convert atmospheric nitrogen (N2) into ammonia (NH3).

Peptidoglycan

A polymer that makes up the cell wall of bacteria, providing structural support.

Binary Fission

The asexual reproduction process in prokaryotes where one cell divides into two identical cells.

Conjugation

A process in which genetic material is transferred from one prokaryotic cell to another through direct contact.

Chemotaxis

The movement of an organism in response to a chemical stimulus.

Photoheterotrophs

Organisms that obtain energy from light and carbon from organic compounds.

Obligate Anaerobes

Organisms that cannot survive in the presence of oxygen.

Cyanobacteria

Photosynthetic bacteria that produce oxygen as a byproduct of photosynthesis.

Fimbriae

Hair-like structures on prokaryotic cells that help them adhere to surfaces.

Gram-positive bacteria

Bacteria that retain the crystal violet stain used in the Gram staining procedure.

Endospores

A dormant, tough structure produced by some bacteria to withstand harsh environmental conditions.