Cell Biology and Cellular Organization Vocabulary Flashcards

Vocabulary flashcards covering basic cell terminology, structures, membrane transport, and organelles based on the lecture notes.

Robert Hooke

Scientist who inspected thin slices of cork in 1665 and described them as consisting of small irregular units called cells.

Eukaryotic Cells

Cells that contain a membrane-bound nucleus, such as human cells.

Prokaryotic Cells

Cells that lack a membrane-bound nucleus, such as bacteria.

Gametes

Sex cells, specifically sperm and oocytes, whose fusion at fertilization forms a zygote.

Somatic Cells

All body cells other than sex cells (gametes).

Cytology

The scientific study of cellular structure.

Cell Physiology

The scientific study of cellular function.

Extracellular Fluid

Also known as interstitial fluid, the fluid located outside and surrounding a cell.

Plasma Membrane

The outer membrane separating the cell contents from extracellular fluid; permeable to small non-polar molecules and impermeable to polar molecules and ions.

Cytosol

The fluid portion of the cytoplasm in which cellular organelles are suspended.

Passive Transport

Controlled movement of ions and molecules across a membrane down their concentration gradient without consuming cellular energy.

Active Transport

Energy-requiring movement of ions or molecules across a membrane against their concentration gradient.

Diffusion

The random mixing of particles in a solution due to their kinetic energy, resulting in net movement from higher to lower concentration.

Osmosis

The net diffusion of free water across a selectively permeable membrane from a region of higher water concentration to lower water concentration.

Isotonic Solution

A solution with the same water concentration as the cytoplasm of the cell, leading to no net movement of water across the membrane.

Hypotonic Solution

A solution with a lower solute concentration than the inside of a cell, causing red blood cells to swell and burst.

Hypertonic Solution

A solution with a higher solute concentration than the inside of a cell, causing red blood cells to shrink.

Hemolysis

The bursting of red blood cells caused by fluid uptake when placed in a hypotonic solution.

Crenation

The shrinking of red blood cells due to water loss when placed in a hypertonic solution.

Facilitated Diffusion

Passive movement of a substance across a membrane down its concentration gradient facilitated by specific transporter protein conformational changes.

Primary Active Transport

An active transport mechanism directly powered by the hydrolysis of ATP using transmembrane protein pumps.

Secondary Active Transport

Active transport powered indirectly by energy stored in an ionic concentration gradient.

Na+/K+ ATPase Pump

A primary active transport pump that uses cellular ATP to continually maintain low cytosolic Na+ and high cytosolic K+ concentrations.

Phagocytosis

A type of endocytosis commonly called 'cell eating' where macrophages and white blood cells engulf whole bacteria, viruses, or large particles.

Pinocytosis

Also called bulk-phase endocytosis or 'cell drinking', a vesicular process where a cell imports extracellular fluid and solutes.

Exocytosis

Process where intracellular vesicles fuse with the plasma membrane to release contents such as enzymes, hormones, or waste to the outside of the cell.

Receptor-Mediated Endocytosis

Selective vesicular transport where target molecules bind to specific plasma membrane receptor proteins before being internalized.

Ribosomes

Molecular complexes of ribosomal RNA and proteins that function as the sites of cellular protein synthesis.

Rough ER

Endoplasmic reticulum continuous with the nuclear envelope and studded with ribosomes; synthesizes, processes, and packages proteins for export.

Smooth ER

Endoplasmic reticulum lacking ribosomes; synthesizes lipids, cholesterol, and steroids, and detoxifies harmful substances like alcohol.

Golgi Complex

An organelle that receives proteins from rough ER via vesicles and modifies, packages, and routes them to their final destinations.

Lysosomes

Membranous vesicles formed by the Golgi complex filled with digestive enzymes used for breaking down foreign materials, autophagy, and autolysis.

Autophagy

The lysosomal process of breaking down and recycling a cell's own damaged or unnecessary organelles.

Autolysis

The breakdown and self-digestion of an entire cell caused by lysosomal enzymes following cellular death.

Peroxisomes

Membranous vesicles smaller than lysosomes that oxidize toxic substances like alcohol and formaldehyde in hydrogen peroxide reactions.

Mitochondria

Double-membrane organelles known as the powerhouse of the cell that self-replicate and generate ATP during cellular respiration.

Cristae

Folds of the inner mitochondrial membrane that provide increased surface area for metabolic reactions.

Microfilaments

The thinnest cytoskeleton filaments composed of actin that interact with myosin to generate cellular movement.

Intermediate Filaments

Cytoskeleton protein fibers, such as keratin, that provide structural reinforcement and resistance to stretching.

Microtubules

Large cylindrical tubulin structures that form internal transport tracks, spindle apparatuses, centrioles, and cilia.

Cilia

Short, hair-like motile projections present in large numbers on cell surfaces that sweep fluids and particles across the cell exterior.

Flagella

Elongated motile tail structures whose continuous undulating propulsion moves cells through liquid environments.

Nucleus

The control center of the cell containing genetic material (DNA) enclosed within a double-membrane envelope.

Nucleolus

A non-membrane-bound dark spherical structure inside the nucleus responsible for ribosome assembly.