The Cell - D2L - Update 2 - Spr25

Cell Theory

The scientific theory that states the smallest unit of life is the cell, all organisms are made of one or more cells, and cells arise from other cells.

Plasma Membrane

A selectively permeable membrane that separates a cell from its extracellular environment and contains various proteins and lipids.

Phospholipid Bilayer

A double layer of phospholipids that makes up the cell membrane, with polar heads facing the aqueous environment and nonpolar tails facing inward.

Osmosis

The diffusion of water across a selectively permeable membrane, moving from an area of lower solute concentration to an area of higher solute concentration.

Active Transport

The energy-dependent process where substances are moved across a cell membrane against their concentration gradient, typically involving ATP.

Facilitated Diffusion

The process of passive transport where molecules move across a membrane via special proteins without the expenditure of energy.

Cytoskeleton

A network of filaments and tubules that provide structural support, shape, and movement in the cell.

Ribosomes

Cellular structures composed of RNA and proteins, responsible for protein synthesis.

Lysosomes

Membrane-bound vesicles containing digestive enzymes that break down waste materials and cellular debris.

Mitosis

The process of cell division that results in two genetically identical daughter cells.

Nucleosome

A structural unit of DNA consisting of a segment of DNA wound around a core of histone proteins.

Chromatin

A complex of DNA and proteins in the nucleus of a cell that condenses to form chromosomes during cell division.

Tonicity

The ability of a solution to change a cell's shape by causing it to gain or lose water.

Vesicular Transport

The process of moving large amounts of material into or out of cells using membrane-bound vesicles.

Integral Proteins

Proteins that are embedded in the lipid bilayer of the cell membrane, functioning in transport and as receptors.

Peroxisomes

Organelles that contain enzymes for oxidative reactions, including the breakdown of fatty acids and detoxification.

Aquaporin

Channel proteins that facilitate the transport of water across cell membranes.

Cilia

Hair-like structures on the surface of cells that facilitate movement of fluids or particles across the cell surface.

Gene

A segment of DNA that encodes a functional product, typically a protein.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins from messenger RNA (mRNA).

Microtubules

The largest component of the cytoskeleton, providing structural support and shape to the cell and enabling intracellular transport.

Endocytosis

The process by which cells engulf substances from outside the cell, enclosing them in vesicles.

Cytoplasm

The material within a cell, excluding the nucleus, containing organelles and cytosol.

Terminators

Sequences in DNA that signal the end of transcription.

Cell Communication

The process by which cells send and receive signals to coordinate their activities.