Microscopy Techniques Overview

Microscopy Techniques

Light microscope: Uses visible light and glass lenses to magnify objects many times.
Compound light microscope: Uses two lenses—objective and eyepiece—for magnification.
Differential staining: Using specific stains to distinguish cell types.
Counterstain: A second stain with a contrasting colour to enhance microscopic viewing.
Electron microscopy: Uses a beam of electrons instead of light, providing higher resolution images than light microscopes.
Ultrastructure: Cellular features visible through electron microscopy.
Artifacts: Structures or objects created during specimen preparation, not actually present within the original sample.
Transmission electron microscope (TEM): Electrons pass through the specimen to create an image.
Scanning electron microscope (SEM): Electrons scan the specimen's surface, producing a three-dimensional image.
Laser scanning confocal microscope: Uses fluorescence and a pin-hole aperture for high-resolution images.

Cell Types and Structures

Prokaryotic cells: Lack membrane-bound nucleus and organelles.
Eukaryotic cells: Possess a nucleus and membrane-bound organelles.
Magnification: Represents how much larger an image appears than the actual object.
Resolution: Ability to distinguish two separate objects as distinct entities.
Cytoplasm: Internal fluid containing cytosol (water, salts, organic molecules), cytoskeleton and organelles.
Metabolism: The sum of all chemical reactions in an organism.
Organelles: Membrane-bound compartments with specific functions within eukaryotic cells.
Nucleus: Cell organelle containing DNA and RNA, crucial for cell growth and reproduction.
Histones: Proteins forming chromatin complexes with DNA.
Chromatin: Uncondensed DNA combined with histones.
Chromosomes: Condensed and coiled chromatin structures visible during cell division.
Mitochondria: Organelles involved in respiration and energy production.
Cristae: Highly folded inner mitochondrial membranes increasing the surface area for reactions.
Matrix: Fluid-filled interior of the inner mitochondrial membrane, where reactions occur.
Mitochondrial DNA: DNA found within the mitochondrial matrix.
Vesicles: Small membrane sacs involved in transporting materials within and out of the cell.
Lysosomes: Vesicles containing enzymes for breaking down waste materials.
Cytoskeleton: Network of protein fibres in the cytoplasm providing structural support and enabling cell movement.
Microfilaments: Actin protein fibres involved in cell movement and cell division.
Microtubules: Tubular structures forming a scaffold, aiding organelle transport.
Intermediate fibres: Fibres providing structural support and maintaining cell integrity.
Centrioles: Cytoskeletal components involved in cell division.
Secretion: Process of releasing substances from cells, glands, or organs.
Endoplasmic reticulum (ER): Network of membranes involved in protein and lipid synthesis.
Rough ER: ER with ribosomes attached, involved in protein synthesis and transport.
Smooth ER: ER without ribosomes, involved in lipid and carbohydrate synthesis and storage.
Ribosomes: Sites for protein synthesis, composed of RNA and proteins.
Golgi apparatus: Organelle modifying, packaging and transporting proteins.
Tonoplast: Membrane surrounding the vacuole in plant cells.
Cell wall: Rigid outer layer found in some cell types, providing support.
Vacuole: Membrane-bound sac used in transporting or storing materials.
Chloroplast: Organelle in plant cells responsible for photosynthesis.
Stroma: Fluid-filled space in chloroplasts surrounding the thylakoid membranes, where reactions occur.
Granum: Stack of thylakoid membranes within chloroplasts, containing chlorophyll for photosynthesis.
Endosymbiosis: Theory explaining how eukaryotic cells evolved from prokaryotic cells.

Molecular Components of Cells

Elements: Pure substances composed of only one type of atom.
Ions: Charged atoms or groups of atoms.
Polymers: Large molecules made up of repeating units (monomers).
Monomers: Small units that form polymers.
Covalent bonding: Strong bonds formed by sharing electrons.
Ionic bonding: Strong bonds formed by transferring electrons.
Polar molecules: Molecules with uneven charge distribution.
Capillary action: Movement of water against gravity through narrow tubes.
Carbohydrates: Organic molecules composed of carbon, hydrogen, and oxygen (CH2O)
Monosaccharides: Single sugar molecule, example Glucose.
Disaccharides: Two monosaccharides joined by a glycosidic bond, examples: Maltose, Sucrose, Lactose
Polysaccharides: Many monosaccharides joined; examples: Starch, Glycogen, Cellulose
Reducing sugars: Can donate electrons, and are tested using Benedict's reagent.
Benedict's reagent: Alkaline copper(II) sulphate solution for testing reducing sugars.
Iodine test: Potassium iodide solution, detects the presence of Starch.
Colorimetry: Measuring the absorption of light using a spectrophotometer.
Lipids: Nonpolar macromolecules, including fats, oils, and phospholipids.
Triglycerides: Made of one glycerol molecule and three fatty acids.
Fatty acids: Long-chain carboxylic acids.
Saturated: Fatty acids without double bonds.
Unsaturated: Fatty acid with double bonds.
Phospholipids: Modified triglycerides with a phosphate group.
Hydrophobic: Repelled by water.
Hydrophilic: Attracted to water.
Surfactants: Compounds that lower water surface tension.
Sterols: Lipids forming ring structures, including cholesterol.
Emulsion test: Laboratory test for lipids using ethanol.
Peptides: Chains of two or more amino acids.
Amino acids: Building blocks of proteins.
Proteins: One or more polypeptides arranged into a complex macromolecule.
R-group: Variable side chains of amino acids defining their properties.
Peptide bond: Bond between two amino acids.
Polypeptide: Chain of three or more amino acids.