Chapter 3: Cells - Structure, Transport, Growth & Clinical Connections

Comprehensive vocabulary flashcards covering cell structure, organelles, membrane transport mechanisms, the cell cycle, and cell death based on nursing-ready clinical review notes.

Selectively permeable

A characteristic of the cell membrane where some substances cross more easily than others.

Phospholipids

Molecules that create a two-layer barrier (bilayer) separating intracellular fluid from extracellular fluid.

Flagellum

One long tail that propels a sperm cell through fluid.

Microvilli

Cell surface specializations that increase surface area for absorption.

Cilia

Hair-like structures that move material across the cell surface.

Nucleolus

The part of the nucleus that builds RNA and ribosome parts.

Chromatin

DNA strands within the nucleus that condense into chromosomes.

Cytoplasm

Everything inside the cell membrane but outside the nucleus, consisting of cytosol, organelles, and inclusion bodies.

Cytosol

The water-rich intracellular fluid where organelles are suspended.

Mitochondria

Organelles that turn fuel into usable $ATP$; they contain inner folds called cristae.

Ribosomes

Structures that build proteins; they can be free (floating in cytosol) or fixed (attached to RER).

Rough ER

Endoplasmic reticulum with ribosomes that synthesizes export proteins and moves them toward the Golgi.

Smooth ER

Endoplasmic reticulum without ribosomes that makes lipids and steroids and supports glycogen metabolism.

Golgi apparatus

The cell’s shipping center that modifies, sorts, and packages proteins into secretory vesicles.

Lysosomes

Organelles containing powerful enzymes that digest worn-out organelles, waste, and bacteria.

Microfilaments

Cytoskeleton components that support movement, especially in muscle cells.

Microtubules

Cytoskeleton components that anchor organelles and form the mitotic spindle.

Centrioles

Paired microtubular structures that organize the spindle to separate chromosomes during mitosis.

Diffusion

The passive movement of particles from an area of high concentration to low concentration until equilibrium is reached.

Facilitated diffusion

A form of passive transport where a membrane protein helper speeds the movement of substances from high to low concentration.

Osmosis

The diffusion of water across a selectively permeable membrane toward the side with more solute (less water).

Isotonic

A solution with the same solute concentration as the cell, resulting in no net water shift.

Hypotonic

A solution with less solute outside the cell, causing water to enter the cell and potentially lead to hemolysis.

Hypertonic

A solution with more solute outside the cell, causing water to leave the cell and leading to crenation.

Hemolysis

The bursting or rupture of red blood cells, often caused by exposure to extremely hypotonic fluids like pure water.

Crenation

The shriveling of a red blood cell when water leaves it in a hypertonic environment.

Filtration

Passive transport driven by pressure, such as capillary hydrostatic pressure moving water and solutes into tissues.

Active transport

Movement of substances "uphill" from low to high concentration requiring $ATP$ and carrier proteins.

Phagocytosis

A type of endocytosis referred to as "cellular eating" where large particles or bacteria are engulfed.

Pinocytosis

A type of endocytosis referred to as "cellular drinking" where fluid and dissolved solutes enter in vesicles.

Exocytosis

The process by which materials like insulin or neurotransmitters are released from the cell via vesicle fusion with the membrane.

Mitosis

Cell division that supports growth and repair, resulting in two genetically identical daughter cells.

Interphase

The part of the cell cycle where the cell prepares to divide, consisting of $G_1$, $S$, and $G_2$ phases.

$S$ Phase

The specific stage of interphase where DNA synthesis (duplication of chromosomes) occurs.

Prophase

The first stage of mitosis where chromosomes condense and the nuclear membrane disappears.

Metaphase

The stage of mitosis where chromosomes line up at the middle of the cell.

Anaphase

The stage of mitosis where centromeres split and chromatids pull apart.

Telophase

The final stage of mitosis where nuclei reform, chromosomes uncoil, and cytokinesis pinches the cytoplasm.

$G_0$ Phase

A resting state where cells are not cycling; cells can remain here for days, years, or permanently.

Differentiation

The process by which stem cells switch on different genetic programs to become specialized cells.

Malignant

A type of tumor that invades nearby tissue and may metastasize to secondary sites.

Apoptosis

Programmed cell death where the cell shrinks and is removed in organized fragments with little inflammation.

Necrosis

Injury-driven cell death caused by factors like hypoxia or toxins, leading to cell swelling, rupture, and inflammation.