BIO NMDCAT

The cytoskeleton is a dynamic network of microfilaments, intermediate filaments, and microtubules that governs cell shape and movement.

Pits are thin depressions in the secondary wall where only the primary wall and middle lamella remain, allowing water to pass between cells.

The rough ER is studded with active ribosomes, serving as the primary site for translating and folding proteins destined for membranes or export.

The nuclear lamina is an interlaced protein mesh made of lamins that supports the nuclear envelope and organizes internal chromatin.

Mitochondria harvest chemical energy from food molecules via cellular respiration, producing ATP to power energy-dependent cell processes.

The plant cell's protoplast shrinks inward while its rigid wall maintains the outer cell shape; the wall-less animal cell shrivels up completely.

Integrins are transmembrane receptor proteins that link the intracellular cytoskeleton to the extracellular matrix, facilitating cell signaling.

The branched sugar chains of the glycocalyx act as molecular tags, enabling the immune system to recognize self cells and coordinate interactions.

Catalase is a tetrameric protein enzyme containing four heme groups, optimized to break down hydrogen peroxide into water and oxygen.

The smooth ER houses the key enzyme pathways required for lipid metabolism, cholesterol processing, and steroid hormone biosynthesis.

Proteinoplasts are specialized, non-pigmented leukoplasts optimized to store high-density protein reserves inside seeds and kernels.

The random, multi-directional alignment of microfibrils allows the primary wall to stretch and expand uniformly in response to turgor.

The plasma membrane contains transport proteins and acts as the true selective barrier regulating what enters or leaves the cytoplasm.

The Casparian strip is a suberized chemical barrier in the endodermis that forces water to enter the living protoplast via symplastic transport.

As a plant cell matures, the central vacuole expands dramatically, compressing the active cytoplasm into a thin layer against the wall.

Turgor pressure acts as a hydraulic jack, stretching the primary wall when specific enzymes loosen the cross-linked cellulose fibers.

Cilia and flagella grow out from a basal body, a structural template built from a modified centriole with a 9+0 microtubule triplet layout.

Hemicelluloses are branched polysaccharides that form hydrogen bonds with cellulose microfibrils, anchoring the structural meshwork.

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