Structure of a prokaryotic cell

Bio 1

Nucleoid

where the chromosomes (DNA) in prokaryotes are organized, proteins can also be found here

Capsule

polysaccharide layer that covers the surface of the cell and hides small proteins that are exposed

Bacterial cell wall

structural component of the bacteria made of peptidoglycan

Gram negative bacterium

has two membranes, outer and cell membrane with a thin peptidoglycan layer between them; pink gram stain

Gram positive bacterium

has a thick peptidoglycan layer and inner cell membrane; dark purple gram stain

Flagella

made of protein flagellin and help the cells move by rotating and propelling the cell forward using proton motor force for energy

Plasma/cell membrane

selective barrier enclosing the intracellular space that controls transport in and out of the cell and can vary in composition throughout species

Glycoproteins and glycolipids

found on the extracellular side of the cell membrane and are responsible for signaling, communication, and identification of cells

Pili and fimbriae

protein appendages that extend from the cell wall outward and are important in adherence to host cells (infectivity and virulence)

Pili

long, less numerous; responsible for attachment that transfers genetic material

Fimbriae

short bristle-like protein structure, numerous; responsible for attachment to host cells or other surfaces for colonization

Plasmids

small circular DNA that has extra genes but are non-chromosomal; found in the cytoplasm

Cytoskeleton

involved in movement of the cell, cell shape, or even cell division; made of protein filaments; found underneath the plasma membrane to help maintain the structure of the membrane

FtsZ protein filaments

tubuline-like; component of the cytoskeleton; responsible for cell division and intracellular transport

MreB protein filaments

actin-like; component of the cytoskeleton; responsible for cell shape, cell motility, maintenance, plasmid segregation, and muscle contraction