Unit 2: The Cell membrane

These flashcards cover key vocabulary and concepts in cellular biology, focusing on cell structure, processes, and transport mechanisms.

Cell Metabolism

The sum of all chemical reactions that a cell carries out to maintain life.

Anabolic Reactions

Building reactions where small molecules are bonded together to form macromolecules.

Catabolic Reactions

Reactions that break down macromolecules back into smaller molecules.

Oxidation-Reduction Reactions

Reactions that convert energy in chemical bonds of nutrients into a usable form of energy for the cell, namely ATP.

Plasma Membrane

The structure that surrounds each cell, isolating its internal structures from the external environment.

Cytoplasm

The part of the cell between the plasma membrane and the nucleus, including cytosol and organelles.

Nucleus

The organelle that contains most of the cell’s DNA and is the primary site for RNA synthesis.

Phospholipid Bilayer

The double layer of phospholipids that forms the plasma membrane, consisting of hydrophilic heads and hydrophobic tails.

Fluid Mosaic Model

Describes the plasma membrane as a dynamic fluid structure with multiple components, some capable of moving within the bilayer.

Selective Permeability

The property of the plasma membrane that allows certain molecules to cross while prohibiting others.

Passive Transport Processes

Transport mechanisms that do not require energy, including diffusion and osmosis.

Active Transport Processes

Transport mechanisms that require energy to move substances against their concentration gradients.

Tonicity

A way to compare osmotic pressure gradients between two solutions.

Endocytosis

The process by which cells ingest large particles or fluids, including phagocytosis and pinocytosis.

Exocytosis

The process where large molecules exit the cell by vesicles fusing with the plasma membrane.