Prokaryotes, Protists, and Viruses Lecture

Comprehensive vocabulary flashcards covering the characteristics, classifications, structures, and metabolic diversity of prokaryotes, protists, and viruses.

Eukaryotic cells

Big and complex cells that contain a nucleus, cell wall, cell membrane, cytoplasm, and membrane-bound organelles.

Prokaryotic cells

Small and simple cells that contain a loop or small rings of DNA, cell walls, cell membrane, cytoplasm, and no membrane-bound organelles.

Binary fission

The asexual mode of reproduction by which prokaryotic cells divide.

Peptidoglycan

A unique material consisting of carbohydrates and amino acids that forms a relatively thick layer in the simpler cell walls of Gram-positive bacteria.

Gram-positive bacteria

Bacteria that have simpler cell walls with a relatively thick layer of peptidoglycan.

Gram-negative bacteria

Bacteria whose cell walls stain differently from Gram-positive bacteria and contain an outer membrane with lipid components.

Endospores

Specialized structures formed by some prokaryotes to survive in extreme environments.

Extreme halophiles

Archaea characterized as 'salt lovers.'

Extreme thermophiles

Archaea characterized as 'heat lovers.'

Methanogens

Archaea that thrive in anaerobic conditions.

Bioremediation

The use of organisms to remove pollutants from soil, air, or water, such as in sewage treatment facilities.

Biofilms

Highly organized communities formed when prokaryotes attach to surfaces; they are difficult to eradicate and cause medical and environmental problems.

Exotoxins

Proteins that bacterial cells secrete into their environment.

Endotoxins

Lipid components of the outer membrane of gram-negative bacteria that are released when the cell dies or is digested by a defensive cell.

Antibiotic resistance

A major challenge in modern medicine contributed to by the overuse and misuse of antibiotics.

Protists

Mostly unicellular eukaryotes that are found in a variety of aquatic or moist habitats.

Algae

Autotrophic protists.

Protozoans

The informal name for heterotrophic protists.

Mixotrophs

Organisms that are capable of both photosynthesis and heterotrophy.

Diatoms

Autotrophic microalgae belonging to the Stramenopila (SAR group) found in oceans and waterways that generate $20 - 50\,\%$ of Earth's oxygen and are thought to be the primary source of oil.

Brown Algae

Autotrophic members of the Stramenopila (SAR group) with multicellular bodies that lack the roots, stems, and leaves of plants.

Red Algae

Mostly multicellular, autotrophic members of the supergroup Archaeplastida that contribute to the structure of coral reefs and include commercially valuable species.

Green Algae

Unicellular, colonial, or multicellular autotrophic members of the supergroup Archaeplastida that derive their green color from chloroplasts with chlorophyll.

Viruses

Non-cellular infectious agents that require a host cell to replicate and are not placed in any domain of life.

Capsid

The protein coat that encloses the viral genetic material (DNA or RNA).

Heterotrophs

Organisms ('other eaters') that use reduced, preformed organic substances as their carbon source.

Autotrophs

Organisms ('self feeders') that use carbon dioxide ($\text{CO}_2$) as their carbon source and convert (fix) it into organic molecules.

Phototrophs

Organisms ('light eaters') that capture or derive their energy from light (sunlight).

Chemotrophs

Organisms ('chemical eaters') that harness or derive energy from chemical sources.

Lithotrophs

Chemotrophs ('rock eaters') that use inorganic chemicals as their energy source (e.g., Nitrosomonas oxidizing $\text{NH}_3$).

Organotrophs

Chemotrophs ('organic eaters') that use organic chemicals as their energy source (e.g., Saccharomyces cerevisiae fermenting glucose).