Lab 1: Cells and Tissues – Vocabulary Flashcards

Vocabulary flashcards covering key terms from Lab 1: Cells and Tissues, including cell structure, fluids, organelles, tissues, osmosis/tonicity, pH/Nernst, cell cycle, and microscopy.

Plasma membrane

The lipid bilayer that encloses the cell and regulates movement of substances; contains hydrophilic heads and hydrophobic tails.

Cytoplasm

All cellular material outside the nucleus, including cytosol and organelles.

Cytosol

The fluid portion of the cytoplasm inside the cell, excluding organelles.

Organelles

Membrane-bound structures within a cell that perform specific functions.

Hydrophilic

Water-loving; polar or charged; dissolves in water and faces aqueous environments.

Hydrophobic

Water-fearing; nonpolar; repelled by water; tends to be in lipid interiors.

Amphiphilic

Molecule with both hydrophilic and hydrophobic regions (e.g., phospholipids).

Extracellular fluid (ECF)

Fluid outside cells, including plasma and interstitial fluid.

Intracellular fluid (cytosol)

Fluid inside cells; component of the cytoplasm.

Na+ (transmembrane concentrations)

Usually ~145 mM extracellular; ~10-15 mM intracellular.

K+ (transmembrane concentrations)

Usually ~5 mM extracellular; ~140 mM intracellular.

Ca2+ (transmembrane concentrations)

Usually ~2-2.5 mM extracellular; ~0.0001-0.001 mM intracellular.

Interstitial fluid

Extracellular fluid in tissue spaces; part of the ECF, closely related to plasma composition.

Plasma (blood plasma)

Fluid component of blood in the circulatory system; extracellular and protein-rich.

Osmosis

Movement of water across a selectively permeable membrane toward higher solute concentration.

Tonicity

Relative solute concentration of a solution affecting cell volume (hypotonic, isotonic, hypertonic).

Hypotonic

Solution with lower solute concentration than the cell; water enters cell.

Isotonic

Solution with equal solute concentration to the cell; no net water movement.

Hypertonic

Solution with higher solute concentration than the cell; water exits cell.

Normal osmolality range

Typical reference range for body fluids around 275–295 mOsm/kg.

Osmolarity

Total concentration of solute particles in a solution (osmoles per liter).

Osmolarity calculation

Sum of molar concentrations of solutes in a solution (Osm = ΣCi).

Nernst equation

Relation between membrane potential and ion concentration gradient (E = (RT/zF) ln(Co/Ci)).

pH

Negative logarithm of hydrogen ion concentration; measure of acidity.

H+ concentration

Amount of hydrogen ions; inversely related to pH via pH = -log10[H+].

DNA transcription

Process of copying DNA sequence into RNA.

RNA translation

Process of synthesizing proteins from mRNA on ribosomes.

Rough endoplasmic reticulum (RER)

ER studded with ribosomes; site of protein synthesis and initial folding.

Ribosome

Ribonucleoprotein particle that translates mRNA into proteins.

Smooth endoplasmic reticulum (SER)

ER lacking ribosomes; involved in lipid synthesis and detoxification.

Golgi apparatus

Stacks of membranes that modify, sort, and package proteins and lipids for delivery.

Vesicle

Small membrane-bound sac that transports substances within the cell or to the membrane.

Mitochondria

Organelle that produces ATP via aerobic respiration; contains its own DNA.

Glycolysis

Anaerobic breakdown of glucose in the cytosol yielding ATP and pyruvate.

Aerobic respiration

Glucose oxidation in mitochondria using oxygen to produce ATP, CO2, and H2O.

Anaerobic respiration

ATP production without oxygen; glycolysis followed by fermentation (e.g., lactate) in humans.

Glucose

Primary monosaccharide fuel for cellular respiration.

Pyruvate

End product of glycolysis; can enter mitochondria for aerobic respiration or be reduced to lactate.

ATP

Adenosine triphosphate; main energy currency of the cell.

Lysosome

Organelle containing hydrolytic enzymes for digestion and recycling of materials.

Hydrolytic enzymes

Enzymes that break chemical bonds through hydrolysis within lysosomes.

Extracellular matrix

Network of proteins and polysaccharides outside cells that provides structure and signaling.

Collagen

Major ECM protein providing tensile strength in tissues.

Proteoglycans

Core protein with glycosaminoglycan side chains; contribute to ECM structure and hydration.

Glycosaminoglycans (GAGs)

Long, negatively charged polysaccharides in ECM that attract water and provide cushioning.

Epithelial tissue

Tightly packed cells lining surfaces and glands; forms barriers and linings.

Endothelial

Cells lining blood vessels; a specialized type of epithelium.

Basal lamina

Thin ECM layer underlying epithelia; supports and separates epithelium from underlying tissue.

Muscle tissue

Tissue specialized for contraction and movement.

Neuronal tissue

Nervous tissue composed of neurons and supporting cells for signal transmission.

Interphase

Stage of the cell cycle where growth and DNA replication occur; not mitosis.

Prophase

First stage of mitosis; chromosomes condense, spindle forms, nuclear envelope breaks down.

Metaphase

Mitotic stage where chromosomes align at the equatorial plate.

Anaphase

Mitotic stage where sister chromatids separate and move to opposite poles.

Telophase

Mitotic stage where chromosomes de-condense and nuclear envelopes reform; cytokinesis may begin.

Cytokinesis

Division of the cytoplasm, producing two separate daughter cells.

Base (microscope)

Bottom support of the microscope; provides stability when placed on a surface.

Arm (microscope)

Supports the body of the microscope and is used to carry it safely.

Stage (microscope)

Flat platform where the slide sits; has clips to hold the slide.

Objective

Lens closest to the specimen; determines magnification.

Coarse focus

Large knob used for rapid, initial focusing at low magnification.

Fine focus

Small knob used for precise focusing at higher magnifications.

Eyepieces (oculars)

Lenses at the top that magnify the image for the viewer.

Condenser

Lens system below the stage that concentrates and directs light onto the specimen.

Diaphragm

Controls light intensity reaching the specimen by adjusting the condenser.

Safe handling of a microscope

Carry with two hands (one on the base, one on the arm) and place on a stable surface.

Focusing technique

Begin with a low-power objective, use coarse then fine focus to bring the specimen into sharp focus.