Chapter 2: Cell Structure and Transport Vocabulary

Vocabulary practice flashcards covering cell anatomy, plasma membrane dynamics, passive and active transport mechanisms, organelles, and cellular structure based on Chapter 2 lecture material.

Nucleus

The gene-containing control center of the cell that houses genetic information and dictates the kinds and amounts of proteins to be synthesized.

Cytoplasm

The cellular contents located between the plasma membrane and the nucleus, consisting of cytosol, organelles, and inclusions.

Plasma Membrane

A selectively permeable membrane that surrounds the cell, acting as a barrier between intracellular and extracellular environments and controlling entry and exit of substances.

Fluid Mosaic Model

Refers to the plasma membrane structure where specialized membrane proteins continually float through a dynamic lipid bilayer, resulting in constantly changing patterns.

Phospholipid Bilayer

The structural basis of the cell membrane composed of water-soluble heads forming outer surfaces and water-insoluble tails forming the interior.

Simple Diffusion

An unassisted passive transport process where substances such as $\text{O}_2$, $\text{CO}_2$, and lipid-soluble molecules move from regions of higher concentration to lower concentration.

Facilitated Diffusion

Passive movement of substances like glucose and amino acids down their concentration gradient using transmembrane protein channels or carriers.

Osmosis

The passive movement of water molecules through a selectively permeable membrane toward a region of higher solute concentration until equilibrium is reached.

Osmotic Pressure

The ability of osmosis to generate enough pressure to move a volume of water; it increases as the concentration of nonpermeable solutes increases.

Isotonic

A solution state having the same osmotic pressure as the surrounding cellular environment.

Hypotonic

A solution state having a lower osmotic pressure than the surrounding cellular environment.

Hypertonic

A solution state having a higher osmotic pressure than the surrounding cellular environment.

Active Transport

A physiological process requiring cellular energy (ATP) in which carrier proteins move substances across a membrane against their concentration gradient from lower to higher concentration.

Primary Active Transport

A form of active transport involving transport proteins and ATP expenditure to move substances against a concentration gradient, such as the $\text{Na}^+/\text{K}^+$ ATPase pump.

Endocytosis

An active vesicular transport process that moves substances into a cell within vesicles formed from the plasma membrane.

Phagocytosis

A form of endocytosis known as 'cell eating,' where pseudopods engulf solid particles or bacteria to form a phagosome.

Pinocytosis

A form of endocytosis known as 'cell drinking' or bulk-phase endocytosis, involving the movement of extracellular fluid into a cell by membrane infolding.

Exocytosis

An active process where substances are moved out of a cell in secretory vesicles that fuse with the plasma membrane and release contents into extracellular fluid.

Transcytosis

The movement of a substance completely through a cell as a result of endocytosis on one side and exocytosis on the opposite side.

Cytosol

The semi-fluid portion of cytoplasm that consists largely of water along with dissolved proteins, salts, sugars, and other solutes.

Mitochondria

Double-membrane organelles containing inner cristae that provide most of the cell's ATP via aerobic cellular metabolism and contain their own DNA and RNA.

Ribosomes

Small granules containing protein and rRNA that function as the primary sites of protein synthesis.

Rough Endoplasmic Reticulum

A ribosome-studded membranous organelle that acts as a 'membrane factory,' manufacturing secreted proteins, integral membrane proteins, and phospholipids.

Smooth Endoplasmic Reticulum

A network of membranous tubules that catalyzes lipid/cholesterol metabolism, drug detoxification in the liver, steroid synthesis in testes, and calcium storage in muscle tissue.

Golgi Apparatus

An organelle composed of stacked, flattened membranous sacs that functions in the modification, concentration, and packaging of proteins.

Cytoskeleton

An elaborate internal series of rods including microfilaments, intermediate filaments, and microtubules that supports cellular structure and movements.

Nuclear Envelope

A selectively permeable double-membrane barrier perforated with nuclear pores that encloses the nucleoplasm and genetic material inside the nucleus.