External Structures of Prokaryotes

These flashcards cover key vocabulary related to the external structures of prokaryotes, including definitions of important terms and concepts discussed in the lecture.

Peptidoglycan

A mesh-like molecule made up of proteins and sugars, which is the single most important feature of the cell wall of prokaryotes.

Gram-positive bacteria

Bacteria that have a thick layer of peptidoglycan and do not have an outer membrane.

Gram-negative bacteria

Bacteria that have a thin layer of peptidoglycan and possess an outer membrane.

Lipid A

The component of lipopolysaccharide that connects it to the outer membrane and can trigger septic shock when released into the body.

Fimbriae

Short, bristle-like structures that help bacteria adhere to surfaces and each other, often found in Gram-negative bacteria.

Flagella

Long, thin, helical appendages that enable motility in bacteria, with various arrangements depending on the bacterial type.

Capsule

A sticky, carbohydrate-enriched layer around some bacteria that aids in adhesion to host tissues.

Periplasmic space

The space between the cell membrane and the outer membrane in Gram-negative bacteria, containing peptidoglycan and numerous enzymes.

Gram Staining

A laboratory technique used to differentiate between Gram-positive and Gram-negative bacteria based on their cell wall structure.

Teichoic Acid

A long polymer made up of fats, sugars, and alcohols found in the cell walls of Gram-positive bacteria.