Microbiology 2401: Chapter 1 History

• Study guide for Microbiology (2401) lectures covers general topics and subtopics.
• Textbook used is "Principles and Explorations" (9th ed., 2009) by Jacquelyn Black.

Chapter 1: History

• Leeuwenhoek was the first to make and study microorganisms with a microscope.
• Redi's experiment disproved spontaneous generation of maggots from meat using open, corked, and cloth-covered jars.
• Resolving power is a lens's ability to distinguish between two distinct objects.
• Pasteur contributed to vaccine creation and developed the first rabies vaccine.
• Pasteur used a swan-necked flask to disprove spontaneous generation, trapping microbes in the neck while keeping the liquid sterile.
• Cell theory states that cells are the basic units of life and perform essential functions.
• Germ theory of disease states that microorganisms can invade organisms and cause disease.
• Koch introduced pure cultures to isolate bacteria and established Koch's postulates to prove the germ theory of disease.
• Koch's postulates: a causative agent must be found in every disease case, isolated in pure culture, and cause the same disease upon inoculation into a healthy animal.
• Spontaneous generation is the theory that living things can originate from nonliving matter.

Chapter 2: Chemistry

• Chemical bonds are formed by the interaction of electrons in atoms' outer shells.
• Covalent bonds are bonds between atoms created by sharing electrons.
• Ionic bonds result from the attraction of oppositely charged ions.
• Hydrogen bonds are relatively weak attractions between hydrogen with a partial positive charge and oxygen or nitrogen with a partial negative charge.
• Acids release hydrogen ions in water; bases absorb hydrogen ions or donate hydroxyl ions.
• pH expresses hydrogen ion concentration, indicating acidity.
• Functional groups are molecular parts that participate in chemical reactions and determine chemical properties.
• Macromolecules are large molecules.
• Carbohydrates are composed of carbon, hydrogen, and oxygen, serving as a primary energy source.
• Monosaccharides are simple carbohydrates with a carbon chain or ring and alcohol, aldehyde, or ketone groups.
• Disaccharides are carbohydrates formed by joining two monosaccharides.
• Polysaccharides are carbohydrates formed by linking many monosaccharides via glycosidic bonds.
• Glycosidic bond is a covalent bond between two monosaccharides, a sugar-alcohol/sugar linkage.
• Lipids are water-insoluble, structural components of cells, and energy sources, containing more energy than carbohydrates.
• Triglycerides are molecules formed from three fatty acids bonded to glycerol.
• Fatty acids have a carboxyl group at one end; saturated contain only single carbon-hydrogen bonds, while unsaturated have at least one double bond.
• Phospholipids are lipids with glycerol, two fatty acids, and a polar head group, found in all membranes.
• Steroids are lipids with a four-ring structure, including cholesterol, steroid hormones, and vitamin D.
• Proteins are polymers of amino acids joined by peptide bonds.
• Amino acids are organic acids containing an amino group and a carboxyl group, building blocks of proteins.
• Peptide bonds are covalent bonds joining the amino group of one amino acid and the carboxyl group of another.
• Primary structure is the specific sequence of amino acids in a polypeptide chain.
• Secondary structure is the folding or coiling of a polypeptide chain into patterns like a helix or pleated sheet.
• Tertiary structure is the folding of a protein molecule into globular shapes.
• Nucleotides are organic compounds with a nitrogenous base, a five-carbon sugar, and one or more phosphate groups, while nucleosides lack phosphate groups.
• Purines (adenine and guanine) have a double ring structure, while pyrimidines (thymine, cytosine, and uracil) have a single ring.
• Ribose is the sugar in RNA, and deoxyribose is the sugar in DNA.
• A phosphate group is a chemical group containing phosphorus and oxygen atoms.
• Phosphodiester bonds are covalent linkages forming the DNA/RNA backbone between the phosphate of one nucleotide and the sugar of the next.
• Complementary base pairing involves hydrogen bonds between adenine and thymine (or uracil) or guanine and cytosine bases.

Chapter 3: Microscopy and Staining

• Units of length include meter (m), centimeter (cm), millimeter (mm), micrometer (µm), nanometer (nm), and angstrom (Å).
• Resolving power measures an optical instrument's resolution.
• Properties of light: reflection (bouncing back), transmission (passage), absorption (light rays neither pass through nor bounce off an object), luminescence (absorbed light re-emitted at longer wavelengths), and refraction (bending as it passes between media of different densities).
• A bright field microscope uses white light to illuminate a sample, creating a dark image against a bright background.
• Darkfield microscopes use visible light with a special condenser to cause light rays to reflect off the specimen at an angle.
• Electron microscopes use visible light with a special condenser to cause light rays to reflect off the specimen at an angle.
• Staining highlights specimens for microscopic study.
• Gram staining identifies bacteria by staining and observing them under a microscope.
• Acid-fast staining detects bacteria causing tuberculosis (TB) and other illnesses.
• Negative staining makes capsules appear clear against a dark background.
• Spore staining identifies endospores in bacteria.

Chapter 4: Prokaryotic/Eukaryotic Cells

• Basic differences: prokaryotes lack a nucleus, while eukaryotes have a nucleus and other organelles.
• Morphology of bacteria: external appearance including size, shape, and arrangement.
• Cell shapes: coccus (spherical), bacillus (rod-shaped), coccobacillus (short, rod-shaped), vibrio (coma-shaped), and spirillum (flexible wavy-shaped).
• Cell arrangements: singles, diplo (pairs), strep (chains), staph (grapelike clusters), and tetrads (cuboidal groups of four).
• Basic components of cell wall: cellulose, hemicellulose, and pectin.
• Gram-positive cell walls have a thick peptidoglycan layer.
• Gram-negative cell walls have a thin peptidoglycan layer between an inner and outer membrane.
• Protein arrangements occur in the membrane
• Glycocalyx: the outermost layer in prokaryotic cells.
• Capsules are protective structures outside the cell wall, secreted by certain bacteria.
• Slime layers are loosely bound to the cell wall, protecting against drying, trapping nutrients, and binding cells together.
• Flagella are slender, threadlike structures for swimming.
• Pili are hollow projections for attachment to surfaces.
• Chemotaxis is nonrandom movement toward or away from chemicals.
• Ribosomes consist of RNA and proteins, used for protein synthesis.
• Storage granules store nutrients, export products, and enzymes.
• Endospores are resistant, dormant structures that survive adverse conditions.
• Eukaryotic cells have a distinct cell nucleus and other membrane-bound structures.
• Diffusion is the movement of molecules down the concentration gradient.
• Osmosis is the process by which water molecules pass through a semipermeable membrane from a less to a more concentrated solution.
• Active transport is the movement of molecules or ions against a concentration gradient, requiring energy from ATP.

Chapter 5: Essential Concepts of Metabolism (Enzymes)

• Metabolism is the sum of all chemical processes in living organisms.
• Anabolism uses energy to synthesize large molecules (synthesis).
• Catabolism is the chemical breakdown of molecules, releasing energy.
• Oxidation is the loss of electrons and hydrogen atoms.
• Reduction reactions are the gain of electrons and hydrogen atoms.
• Autotrophs are nutritionally deficient mutants unable to synthesize a particular enzyme.
• Heterotrophs use compounds to produce biomolecules.
• Enzymes are protein catalysts that control the rate of chemical reactions in cells.
• Glycolysis is an anaerobic pathway that breaks down glucose into pyruvic acid, producing some ATP.
• Fermentation, Kreb's Cycle, Substrate Phosphorylation, Electron Transport Chain, Aerobic and anaerobic Growth, and Respiration are other biological processes.
• Respiration accounts for energy production and the production of NAD/NADH, FAD/FADH, CO2, and ATP.
• Chemiosmosis synthesizes ATP.