Helicase ________

Bacterial cell membranes are composed of a phospholipid bilayer in which the hydrophilic (water-attracting) heads face outward toward the aqueous environment both inside and outside the cell, while the hydrophobic (water-repelling) tails are buried in the interior of the membrane, away from water. This arrangement creates a selectively permeable barrier that regulates the movement of substances into and out of the cell. The correct orientation of phospholipids is critical for maintaining membrane integrity, fluidity, and proper function of embedded proteins, transport systems, and signaling molecules.

A. Coccus: A coccus is a spherical or round-shaped bacterium. Cocci can exist singly, in pairs (diplococci), chains (streptococci), clusters (staphylococci), or other arrangements depending on their pattern of division. The shape is an important morphological characteristic used in bacterial identification and classification in clinical microbiology.

B. Bacillus: A bacillus refers to a rod-shaped bacterium. Bacilli can occur singly or in chains and may be aerobic or anaerobic. Their elongated shape distinguishes them from cocci and influences how they move, attach to surfaces, and form spores.

C. Vibrio: A vibrio is a comma-shaped or curved rod-shaped bacterium. Vibrio species, such as Vibrio cholerae, are typically associated with aquatic environments and have distinct motility patterns. Their curved morphology differentiates them from cocci and bacilli.