Practice Questions

The smooth ER in hepatocytes contains cytochrome P450 enzyme families that chemically modify and detoxify hydrophobic drugs and toxins.

The nucleolus functions as a ribosome manufacturing center, transcribing rRNA and combining it with proteins to form ribosomal subunits.

Tight junctions form a continuous fluid-tight seal between adjacent cell membranes, preventing materials from leaking between cells.

Invaginating the inner mitochondrial membrane into cristae creates a large surface area for housing electron transport chain complexes.

A hypertonic environment draws water out of the animal cell, collapsing its volume and causing the cell membrane to wrinkle and shrivel.

Bacterial cell walls are made of peptidoglycan (glycan chains cross-linked by short peptides), whereas plant walls rely on cellulose.

Exocytosis involves routing transport vesicles from the Golgi to the plasma membrane, where they fuse to release their contents outside.

A desmotubule is a continuous tube of specialized endoplasmic reticulum that runs through the center of a plasmodesmatal channel.

Both plant and animal cells rely on the conserved F1​F0​-ATP synthase complex to generate ATP through oxidative phosphorylation.

Lacking a rigid cell wall allows the animal plasma membrane to stretch, fold, and change shape smoothly, guided by the dynamic cytoskeleton.