Cells and Cell Biology

Comprehensive vocabulary flashcards covering fundamental cellular components, organelle functions, membrane dynamics, and cytoskeletal structures.

DNA

The genetic material used by all cells.

RNA

The intermediate molecule used by all cells to express genome information.

Ribosomes

Cellular structures that translate information carried in RNA into proteins.

Proteins

The structural building blocks and catalytic machines of the cell.

Plasma membrane

A bilayered and dynamic membrane that defines all cells, forms boundaries, performs vital physiological roles, and regulates molecule movement between compartments.

ATP

The immediate energy source used by all cells.

Prokaryotes

Generally smaller, single-celled organisms belonging to Bacteria and Archaea that lack a membrane-enclosed nucleus and other membrane-enclosed compartments.

Eukaryotic cells

Larger and more complex cells defined structurally by possessing a membrane-enclosed nucleus and other membrane-enclosed compartments or organelles.

Organelle

An internal compartment in a eukaryotic cell that is defined by its own membrane and possesses a specific role determined by its molecules and chemical processes.

Cytosol

The jelly-like fluid composing the cell interior.

Cytoplasm

The entire cellular interior comprising the cytosol plus organelles.

Endomembrane system

A group of membranes and organelles in eukaryotic cells that work together to modify, package, and transport lipids and proteins.

Fluid-like membrane behavior

The characteristic of membranes where phospholipids are able to spin, move, and bob within each layer because they are not physically linked to one another.

Cell wall

A rigid layer located immediately outside the plasma membrane that provides structural support, shape, protection, and acts as a selective barrier.

Peptidoglycan

A sugar-and-amino-acid molecule that composes bacterial cell walls.

Cellulose

The most abundant organic molecule on Earth and the primary composition of plant cell walls.

Cytoskeleton

A cellular framework that maintains cell shape/support, positions organelles, enables cell movement, and provides tracks for motor proteins moving materials inside cells.

Intermediate filaments

Flexible, rope-like cytoskeletal assemblages made from fibrous protein monomers intertwined into larger, thicker cords that stabilize cell structure and resist tension.

Microfilaments

Cytoskeletal elements composed of actin monomers that organize as filaments, bundles, or networks and are involved in cell contraction, cytoplasmic streaming, and cell crawling.

Actin

The protein monomer that assembles to form microfilaments.

Myosins

Motor proteins associated with microfilaments whose tail interactions create multi-headed motor cables capable of immense contractile strength when moving along actin.

Cytoplasmic streaming

The internal movement of fluid and organelles within plant cells caused by the movement of myosins on actin filaments.

Microtubules

Hollow cylinders made of tubulin protein dimer subunits that regularly assemble and disassemble, providing a rigid intracellular skeleton and tracks for motor proteins.

Tubulin

The protein dimer subunit that forms hollow cylindrical microtubules.

Kinesins and dyneins

Motor proteins that consume ATP to move along microtubules, binding the microtubule at one end while attaching to cargo or other structures at the other.

Cilia

Hair-like cellular projections (singular: cilium) found lining the epithelial cells of respiratory tract airways to move mucus and trapped debris out of the lungs into the throat.

Flagella

Cellular projection structures used for movement, whose singular form is flagellum.