In this one-minute video, I will walk you through the essential components of gram-negative bacteria.
Gram-negative bacteria are characterised by their membranes. Unlike gram-positive bacteria, which are made up of a single membrane layer, gram-negative bacteria possess two membranes (outer and inner) and a periplasmic space containing a peptidoglycan cell wall. The outer membrane consists of phospholipids and lipopolysaccharides, contributing to the stiffness and structural integrity of the bacterial cell. Many bacterial species also have a flagellum (or multiple flagella) and fimbriae (singular: fimbria), allowing for swimming and swarming motility. Several membrane proteins within the membrane layers function as portals for molecules, while some operate as motors for the flagella. Porins are a type of membrane protein found in the outer membrane that controls the passage of small molecule solutes into the cell interior and plays a structural role in maintaining the integrity of the bacterial cell surface.
Inside bacteria, you can find a nucleoid, ribosomes, and plasmids floating in the cytoplasmic space. The nucleoid contains all the genetic material necessary for controlling the activity and reproduction of the cell, while plasmids are small, circular, double-stranded DNA molecules that provide genetic advantages to the bacteria. Ribosomes function as micro-machines that synthesize proteins according to the genetic code. There are approximately 15,000 ribosomes in a typical bacterial cell.
Music by ComaStudio from Pixabay.
Created 2023