Lab 2 Cytology Vocabulary Flashcards

Vocabulary practice flashcards generated from Lab 2 Cytology transcript covering cellular structures, organelles, diffusion, osmosis, and membrane dynamics.

Plasma membrane

The flexible outer boundary of a cell that separates the cell from its surroundings and controls what enters and leaves.

Phospholipid bilayer

Two layers of phospholipids that form the basic structure of the cell membrane.

Polar phosphate head

The hydrophilic (water-liking) portion of a phospholipid that faces the watery fluid inside and outside the cell.

Nonpolar fatty acid tails

The hydrophobic (water-avoiding) portion of a phospholipid that points inward away from water.

Integral membrane proteins

Proteins that span across the plasma membrane.

Peripheral membrane proteins

Proteins that sit on only one surface of the plasma membrane.

Cholesterol

A lipid molecule present in the plasma membrane that helps stabilize its structure.

Glycoproteins and glycolipids

Membrane surface molecules that help cells recognize one another.

Selectively permeable

A property of a membrane allowing certain substances to pass through while restricting others.

Microvilli

Small folds or projections of the plasma membrane that increase surface area for fast absorption.

Cytoplasm

The region between the plasma membrane and the nucleus containing cytosol, cytoskeleton, and organelles.

Cytosol

The fluid part of cytoplasm containing water, dissolved substances, RNA, enzymes, and other proteins.

Cytoskeleton

A framework of protein filaments that supports the cell and assists with shape and movement; consists of actin, intermediate filaments, and microtubules.

Actin filaments

Protein filaments near the membrane that support cell shape, aid cell movement, and form the core of microvilli.

Intermediate filaments

Rope-like protein fibers that strengthen the cell and maintain organelle and nuclear shape.

Microtubules

Large hollow protein tubes that support cell shape, hold organelles, transport material within the cell, and assist during cell division.

Cilia

Multiple short cell extensions containing microtubules that beat together to propel material past a cell.

Flagellum

A single long, whip-like cell extension containing microtubules that propels an entire sperm cell.

Organelle

A small specialized cellular structure that performs a specific function.

Peroxisomes

Enzyme-containing organelles that process fatty acids (producing hydrogen peroxide), generate nervous system phospholipids, and break down fatty acids for energy.

Mitochondria

Double-membrane organelles that produce most of the cell's ATP by breaking down glucose and fatty acids; contain their own matrix, DNA, and ribosomes.

Ribosomes

Non-membrane-bound structures composed of two subunits (proteins and rRNA) that assemble protein chains.

Rough endoplasmic reticulum (Rough ER)

Membrane-enclosed sacs studded with ribosomes that fold and modify newly made protein chains before packaging them into transport vesicles.

Smooth endoplasmic reticulum (Smooth ER)

Membrane-enclosed sacs lacking ribosomes that detoxify wastes, alcohol, and drugs, synthesize lipids, and store and release calcium ions for muscle contraction.

Golgi apparatus

An organelle that receives proteins from the ER, modifies them further, and sorts and packages them into vesicles for specific destinations.

Protein shipping route

The pathway of protein production and movement: Ribosome builds protein chain $\rightarrow$ Rough ER folds/modifies $\rightarrow$ Transport vesicle carries $\rightarrow$ Golgi finishes, sorts, and packages.

Lysosomes

Organelles containing digestive enzymes that break down incoming materials, old cell parts, or whole damaged cells.

Centrioles

A pair of microtubule-based structures located in the centrosome that help organize cellular microtubules.

Nucleus

The organelle housing genetic instructions that directs the synthesis of nearly all body proteins and some nucleic acids.

Nuclear envelope

The double membrane surrounding the nucleus containing nuclear pores that regulate exchange between nucleus and cytoplasm.

Chromatin

DNA complexed with proteins within the nucleus that condenses into visible chromosomes during cell division.

Nucleolus

A specialized region inside the nucleus rich in rRNA where ribosome subunits begin assembly.

Intracellular fluid (ICF)

The fluid contained within cells, also known as cytosol.

Extracellular fluid (ECF)

The fluid located outside of cells.

Solute

The substance dissolved in a solution.

Solvent

The dissolving agent in a solution, primarily water in biological systems.

Passive transport

Movement of substances across a membrane without requiring cellular ATP energy.

Active transport

Movement of substances across a membrane requiring expenditure of cellular energy (ATP).

Concentration gradient

A difference in the concentration of a particular substance between two distinct areas.

Diffusion

Net movement of solute particles from an area of higher concentration to lower concentration down a concentration gradient without ATP.

Equilibrium (in diffusion)

The state where solute particles are evenly distributed, resulting in equal movement in all directions with no net movement.

Osmosis

Net movement of water across a selectively permeable membrane toward a region with a higher concentration of non-crossing solute.

Osmotic pressure (OP)

The external pressure required to prevent water movement into a solution via osmosis.

Tonicity

The ability of an extracellular solution to alter a cell's water volume based on non-crossing solute concentrations.

Isotonic ECF

An extracellular fluid with an effective non-crossing solute concentration equal to the cell interior, resulting in constant cell volume.

Hypertonic ECF

An extracellular fluid with a higher non-crossing solute concentration than the cell interior, causing water egress and cell shrinking (crenation).

Hypotonic ECF

An extracellular fluid with a lower non-crossing solute concentration than the cell interior, causing water ingress, cell swelling, and potential bursting (lysis).