Parts of the Cell & Cell Membranes

A collection of flashcards covering key terms and definitions related to parts of cells, cell membranes, transport mechanisms, and their functions.

Prokaryotic cells

Cells without organized nuclei, containing genetic material in a nucleoid.

Eukaryotic cells

Cells with organized nuclei, where genetic material is enclosed in a phospholipid membrane.

Cell membrane (plasma membrane)

A bilayer consisting mainly of phospholipids, which regulates what enters and exits the cell.

Gram stain

A method used to differentiate bacterial species based on the characteristics of their cell walls.

Osmosis

The movement of water from higher concentration to lower concentration across a semi-permeable membrane.

Filtration

The passive movement of molecules through a membrane with larger holes than a semi-permeable membrane.

Passive transport

The movement of molecules across the cell membrane without the use of energy.

Active transport

The movement of molecules against their concentration gradient, requiring energy.

Endocytosis

The process of taking large materials into a cell by engulfing them in a vesicle.

Exocytosis

The process of expelling substances from a cell by vesicle fusion with the cell membrane.

Ligand

An extracellular signaling molecule that binds to a receptor.

Ion channels

Transmembrane proteins that allow specific ions to pass through the cell membrane.

Facilitated diffusion

The process of transporting substances across a cell membrane with the help of carrier proteins.

Receptor-mediated endocytosis

A selective process in which cells take in cholesterol or other substances via receptor binding.

Sodium-Potassium Pump (Na+/K+ ATPase)

A primary active transport system that moves sodium out of the cell and potassium into the cell.

Symport system

A transport mechanism where two substances move in the same direction across a membrane.

Antiport system

A transport mechanism where two substances move in opposite directions across a membrane.