Question

"The typical prokaryotic flagellum features:__________ a. a membrane-enclosed organelle with motor proteins. b. an internal 9 + 2 pattern of microtubules. c. a basal body that is similar in structure to the cell's centrioles. d. a complex ""motor"" embedded in the cell wall and plasma membrane. e. an external covering provided by the plasma membrane."

Answer 1

D

Step-by-step explanation:

Flagella are filamentous protein structures attached to the cell surface that provide the swimming movement for most motile prokaryotes. Prokaryotic flagellum is thinner ( below 20 nanometers diameter) than eukaryotic flagellum, and they lack the typical "9 + 2" arrangement of microtubules. The flagellar filament is rotated by a motor apparatus in the plasma membrane allowing the cell to swim in fluid environments. Bacterial as a prokaryote has its flagellum powered by proton motive force (chemiosmotic potential) established on the bacterial membrane, rather than ATP hydrolysis which powers eukaryotic flagella.

The bacterial flagellum is composed of three structurally defined parts; The (1.) FILAMENT, which is a long narrow helical structure composed of subunits of a protein called Flaggelin. At the proximal end of the long filament, is the (2.) HOOK, whose morphological, serological and chemical structures are distinct from the filament. The hook enters the cell wall where it says attached to a complex motor portion of the flagellum called the (3.) BASAL BODY. The hook connects the filament to the basal body, which is the only region of the flagellum inside the cell wall).

The basal body is anchored in the plasma membrane and cell wall where it functions as a rotary molecular motor, enabling the flagellum to rotate and propel the bacterium cell through the surrounding fluid. There are presence of rings surrounded by proteins called MOT. These proteins actually drive the flagellar motor causing rotation of the filament.

Answer 2

The correct option is d. a complex ""motor"" embedded in the cell wall and plasma membrane.

Step-by-step explanation:

Flagella are a structure or extensions of the plasma membrane that serve to propel the cell or to move material over them. Prokaryotes are capable of moving through flagella equipped with a rotating motor, which anchors the scourge in the plasma membrane. In this type of cells, the prokaryotic flagellum is made up of protein fibers that extend outward from the body of the cell (bacteria). The thrust or rotation of the bacterial scourge is a product of the energy coming from the proton-motive force and not directly from the ATP. Prokaryotic flagellum are characterized by not rotating at a constant speed. This parameter will depend on the amount of energy the cell is producing at a given time (the proton flow through the plasma membrane).