Of the following given choices;
A. Carbohydrates, Starch
B. Nucleotides, DNA
C. Fats, Oleic acids
D. Protein, Flagellin
The answer is; D.
The protein flagellin is a globular protein. When the units bond in sequence, they form a hollow filament shaped like a helical screw. It propels the bacteria by rotating like a motor powered by proton motive force.
Protein, flagellin
Bacterial flagella are chemically composed of pure protein (a type of polymer), and the polymer is known as flagellin.
Bacterial flagella are whip-like appendages that extends from the cell body of certain bacteria. Bacteria mainly use the flagella for movement and it can also be used as a sensory organelle. Flagella have different structure, protein component and mechanism of propulsion. The bacterial flagella are helical shaped, thick hollow tubes that are chemically composed of the protein flagellin.