Microbio 3

• Microbiology with Diseases by Body System, Second Edition, covers the processes of life including growth, reproduction, responsiveness, and metabolism.
• Prokaryotes do not have a membrane surrounding their DNA and lack a nucleus, have various internal structures bound with phospholipid membranes, are small, approximately 1.0 μm in diameter, have a simple structure, and are composed of bacteria and archaea.
• The cytoplasm of Eukaryotes contains membranous organelles such as Chloroplasts, which are light-harvesting structures found in photosynthetic eukaryotes.
• Chloroplasts have two phospholipid bilayer membranes and DNA.
• Chloroplasts contain 70S ribosomes.
• atrix contains 70S ribosomes and is a circular molecule of DNA.
• Eukaryotes have a membrane surrounding their DNA and a nucleus, have internal membrane-bound organelles, are larger, 10-100 μm in diameter, have a more complex structure, and are composed of algae, protozoa, fungi, animals, and plants.
• The cell wall of prokaryotes is made up of polysaccharides and proteins, also known as pseudo murein.
• The lipid membrane of prokaryotes is ether linked, with the branching of aliphatic acids.
• The cell wall of bacteria is made up of peptidoglycan with muramic acid.
• Animals are eukaryotic organisms with a lipid bilayer, with sterols (cholesterol), and external structures such as glycocalyces, a capsule composed of organized repeating units of organic chemicals, a slime layer, and fimbriae and pili.
• Protozoa are eukaryotic organisms with no lipid bilayer, with sterols (ergosterol), and external structures such as glycocalyces, a capsule composed of organized repeating units of organic chemicals, a slime layer, and fimbriae and pili.
• Fungi are eukaryotic organisms with a chitin lipid bilayer, with sterol (ergosterol), and external structures such as glycocalyces, a capsule composed of organized repeating units of organic chemicals, a slime layer, and fimbriae and pili.
• Bacteria have a lipid membrane of ester bonds with fatty acids.
• Algae are eukaryotic organisms with a lipid bilayer, with sterols (phytosterols), and external structures such as glycocalyces, a capsule composed of organized repeating units of organic chemicals, a slime layer, and fimbriae and pili.
• The external structure of Eukaryotic Cells includes glycocalyces, which are never as organized as prokaryotic capsules, and Eukaryotic Cell Walls & Cytoplasmic Membranes, which are composed of various polysaccharides, with cellulose found in plant cell walls, fungal cell walls composed of cellulose, chitin, and/or glucomannan, and algal cell walls composed of cellulose, proteins, agar, carrageenan, silicates, algin, calcium carbonate, or a combination of these.
• Glycocalyces are never as organized as prokaryotic capsules but help anchor animal cells to each other, strengthen cell surface, provide protection against dehydration, and function in cell-to-cell recognition and communication.
• Endospores are unique structures produced by some bacteria that are a defensive strategy against unfavorable conditions.
• Ribosomes - site of protein synthesis
• All eukaryotic cells have a cytoplasmic membrane, which is a fluid mosaic of phospholipids and proteins, contains steroid lipids to help maintain fluidity, and contains regions of lipids and proteins called membrane rafts.
• The cytoplasm of Eukaryotes contains structures such as flagella, which have a shaft composed of tubulin arranged to form microtubules in a “9 + 2” arrangement, and cilia, which are shorter and more numerous than flagella, composed of tubulin in “9 + 2” and “9 + 0” arrangements, and are used to move substances past the surface of the cell.
• Up to 60% mycolic acid in acid-fast bacteria helps cells survive desiccation.
• Prokaryotic cytoplasmic membranes maintain concentration and electrical gradient, and chemicals are concentrated on one side of the membrane or the other.
• Prokaryotic cytoplasmic membranes are selectively permeable, naturally impermeable to most substances, and proteins allow substances to cross the membrane by passive or active processes.
• Voltage exists across the prokaryotic cytoplasmic membrane.
• Prokaryotic cytoplasmic membranes, referred to as phospholipid bilayer, are composed of lipids and associated proteins, approximately half of which are proteins that act as recognition proteins, enzymes, receptors, carriers, or channels.
• Archaeal cell walls do not have peptidoglycan, contain a variety of specialized polysaccharides and proteins, and are stained based on their Gram-positive or Gram-negative nature.
• The cytosol is the liquid portion of the cytoplasm, and inclusions may include reserve deposits of chemicals.
• Gram-positive bacteria retain crystal violet dye in the Gram staining procedure, so they appear purple.
• There are two basic types of bacterial cell walls: Gram-positive and Gram-negative.
• Gram-negative bacteria appear pink following the Gram staining procedure.
• Gram-positive cell walls have a relatively thick layer of peptidoglycan, contain unique polyalcohols called teichoic acids, and are covalently linked to lipids, forming lipoteichoic acids that anchor peptidoglycan to the cell membrane.
• Gram-negative cell walls have only a thin layer of peptidoglycan, a bilayer membrane outside the peptidoglycan contains phospholipids, proteins, and lipopolysaccharide (LPS), and may be an impediment to the treatment of disease.
• Endoplasmic reticulum has two forms: smooth endoplasmic reticulum (SER) which plays a role in lipid synthesis, and rough endoplasmic reticulum (RER) which has ribosomes attached to its outer surface and transports proteins produced by ribosomes.
• The centrosome is the region of cytoplasm where centrioles are found.
• Nucleoplasm contains chromatin, which are masses of DNA associated with histones.
• Lysosomes contain catabolic enzymes.
• Endoplasmic reticulum is a netlike arrangement of flattened, hollow tubules continuous with nuclear envelope and functions as a transport system.
• The cytoskeleton of eukaryotes is made up of tubulin microtubules, actin microfilaments, and intermediate filaments.
• Nucleus is often the largest organelle in the cell, contains most of the cell’s DNA, and is semi-liquid.