Structural Diversity in Bacteria

These flashcards cover key vocabulary related to the structural diversity of bacteria, including definitions of important cellular components, morphology, and functions.

Lipoprotein

A molecule made up of a lipid and a protein, found in the membranes of bacteria.

Peptidoglycan

A polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, providing structural support.

Lipopolysaccharide

A large molecule consisting of a lipid and a polysaccharide, found in the outer membrane of Gram-negative bacteria; can act as an endotoxin.

Porin

Proteins that form channels in the outer membrane of bacteria, allowing the passage of small molecules and ions.

Outer Membrane

The phospholipid bilayer that surrounds the cell wall of Gram-negative bacteria, providing an additional barrier.

Periplasmic Space

The space between the outer membrane and the plasma membrane in Gram-negative bacteria, containing various proteins and enzymes.

Cytoplasmic Membrane

Also known as the plasma membrane, it is selectively permeable and involved in transport processes.

Morphology

The study of the form and structure of organisms, which in bacteria includes arrangement, shape, and size.

Endospore

A dormant, resistant structure formed by certain bacteria as a survival mechanism under unfavorable conditions.

Fimbriae

Short, hair-like appendages on bacterial cell surfaces that assist in adherence to surfaces.

Flagella

Long, thread-like appendages that provide motility to bacteria through a rotary action.

Capsule

A well-organized layer of polysaccharides surrounding the cell wall of some bacteria, offering protection.

Slime Layer

A loose, unorganized layer of polysaccharides that provides protection and helps in adhesion.

Gram Positive Bacteria

Bacteria that have a thick peptidoglycan layer in their cell wall, retaining the crystal violet stain used in Gram staining.

Gram Negative Bacteria

Bacteria that have a thin peptidoglycan layer and an outer membrane, not retaining the crystal violet stain in Gram staining.

Nucleoid

A region within a prokaryotic cell where the single, circular DNA molecule is located, not surrounded by a membrane.

Plasmid

Small, circular DNA molecules found in bacteria, often containing genes that confer advantages like antibiotic resistance.

Mesosome

An invagination of the plasma membrane in Gram-positive bacteria, thought to play a role in cell division.