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Microbio Midterm #1
Word Bank Concepts
Concept | Description |
---|---|
Prokaryotic Cell Characteristics | -Nucleoid -Circular DNA that floats freely -Simpler DNA -No membrane bound organelles -Typically much smaller -Divide by binary fission -Typically unicellular -Anaerobic and aerobic |
Eukaryotic Cell Characteristics | -Nucleus -Linear DNA that is in the nucleus -Complex DNA -Membrane bound organelles -Typically much larger -Divide by mitosis and meiosis -Typically multicellular -Aerobic |
Shared Characteristics between Prokaryotic and Eukaryotic Cells | -Chromosomes -DNA as genetic material -Ribosomes -Cytoplasm -Plasma Membrane -Sometimes have cell walls -Vacuoles |
Bioremediation | -Bacteria clean up sewage and organic wastes -Bacteria degrade and detoxifies pollutants such as oil and mercury -Biological insecticides (microbes that are pathogenic to insects and use to prevent insect damage to crops) |
Robert Koch | The first person to conclusively prove that a specific bacteria caused a disease (Germ Theory) |
Edward Jenner | -Vaccinations -Innoculated a person with cow pox virus, who was immune to small pox |
Valence Electrons | -Number of electrons in outer energy shell of an atom -There are 8 electrons in the outermost shell -When the atom's outer shell is only partially filled, the atom is chemically unstable |
Electronic Configuration | -2 electrons in the intermost shell (lowest energy level) -8 electrons in the second shell -8 electrons in the third shell -4th, 5th, and 6th electon shells can accomodate 18 electrons |
Ionic Bonds | -Atoms gain or lose electrons -Bonds are attracted between ions of opposite charge -Two types of ions: Cations (+) and Anions (-) -Ionic Compound: one consisting of ionic bonds Ex) Na+Cl=NA+Cl- |
Covalent Bonds | -Involve the sharing of one or more pairs of electrons -Strongest type of bond -Covalent bonds are formed by the sharing of electrons between atoms |
Hydrogen Bonds | -When a hydrogen atom that is covalently bonded to one oxygen or nitrogen atom is attracted to another oxygen or nitrogen atom -Such bonds are weak and do not binds atoms into molecules |
Isotopes | -Variant forms of the same element -Have different numbers of neutrons and therefore different masses -Have the same numbers of protons and electrons |
Acids | -Substances that donates protons (H+) -Separate into one or more protons and anion -Acids increase the relative (H+) of a solution - |
Base | -A substance that accepts protons (H+) -Many bases separate into one of more positive ions (cations) and a hydroxide ion -Decrease the relative H+ of a solution and increases the relative (OH-) |
pH | -A scale used to measure how basic or acidic a solution is -Ranges from 0-14 -Neutral:7 -Acidic: Less than 7 -Basic: Greater than 7 -As H+ increases pH decreases |
Buffer | -Substance which prevents sudden large changes in pH when acids or bases are added -Biologically important because most of the chemical reactions required for life can only take place within narrow pH ranges |
Carbohydrates | -Molecules that store energy and are used as building materials -Includes simple sugars and their polymers -Diverse group includes sugars, starches, cellulose -Biological Functions: Fuels energy storage, structural component (cell walls), DNA/RNA com |
Types of Carbohydrates | -Monosaccharides -Disaccharides -Polysaccharides |
Proteins | -Large three-dimensional macromolecules responsible for most cellular functions -Macromolecule composed of one or more polypeptide chains folded into a specific 3-D conformation |
Types of Proteins | -Enzymes -Structural Proteins -Transport -Communication -Defensive -Contractile -Storage |
Lipids | -Fats, phospholipids, and steroids |
Simple Lipids | -Contain Carbon, Hydrogen, and Oxygen only |
Complex Lipids | -In addition to C,H, and O, also contain other elements, such as phosphorus, nitrogen, and sulfur |
Nucleic Acid | -A polymer of nucleotides |
Nucleotide | -Subunits of DNA or RNA |
Nucleotides | -DNA and RNA are polymers of nucleotides -Have three components: Pentose Sugar (ribose or deoxyribose), Phosphate group to link nucleotides, nitrogenous base (A,G,C,T, or U) |
Coccus (plural: cocci) | -Spherical |
Diplococci | -A pair of attached cocci -Remain attached after dividing |
Streptococci | -Chainlike arrangement |
Tetrads | -Groups of four -Divide in two planes |
Sarcinae | -Groups of eight -Divide in three planes |
Staphylococci | -Grapelike clusters -Divide in multiple planes |
Bacillus | -Rod-shaped -Most appear as single rods |
Diplobacilli | -A pair of attached bacilli -Remain after dividing |
Coccobacillus | -Intermediate shape between coccus and bacillus -Oval rods |
Spiral Bacteria | -Have one or more twists |
Vibrio | -A comma shaped cell -Look like curved rods |
Spirilla | -Helical, corkscrew shaped bacteria with rigid bodies |
Spirochetes | -Helical bacteria with flexible bodies -Use axial filaments to move |
Pleomorphic Bacteria | -Have several possible shapes |
Glycocalyx | -"Sugar Coat" -All polysaccharide containing substances found external to cell wall, from the thickest capsule to the thinnest slime layers -All bacteria have to least a thin slime layer -Chemical composition varies widely with species |
Glycocalyx Functions | -Attachment to host cells -Source of nutrition -Prevent Dehydration -Escape host immune system |
Gram + Cell Walls | -Consists of several layers of peptidoglycan, which form a thick, rigid structure -Contain teichoic acids, which are made up of an alcohol and a phosphate group |
Gram - Cell Walls | -Thinner, more complex, and more susceptible to mechanical breakage than that of Gram + -Consists of one or a few peptidoglycan layers and an outer membrane -Peptidoglycan is bonded to lipoproteins in the outer membrane and periplasmic space |
Acid-Fast Bacteria | -Cell wall is thick like that of Gram-positive -Contains 60% lipids and much less peptidoglycan -Has a waxy consistency -Stain as Gram + -Grow slowly because nutrients penetrate inefficiently and cells spend a lot of energy making lipids |
Mycoplasmas | -Smallest known bacteria that can grow and reproduce outside of host cells -No cell wall -Pass through most bacterial filters -Plasma Membrane contains lipids called sterols, which protect them from osmotic lysis |
Passive Transport | -Substances move spontaneously from an area of high concentration to one of low concentration -Do not require energy expenditure (ATP) by the cell |
Passive Transport Processes | -Simple Diffusion -Facilitated Diffusion -Osmosis |
Active Transport | -Requires carrier proteins or pumps in plasma membrane |
Active Processes | -Substances are concentrated, i.e., moved from an area of low concentration to one of high concentration |
Osmosis | -Net movement of water (solvent) molecules across a semipermeable membrane from an area of high concentration to one of low concentration of water. |
Osmotic Pressure | -Pressure required to prevent the movement of pure water into a solution. |
Endosymbiotic Theory | -Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria. |
Eukaryotic Cell Structure | -Larger than prokaryotic cells -Nucleus: Protects and houses DNA -Membrane-bound Organelles |
Eukaryotic Organelle Functions | -Separate and store compounds -Store energy -Work surfaces -Maintain concentration gradients |
Membrane-Bound Organelles of Eukaryotic Cells | -Nucleus -Rough Endoplasmic Reticulum (RER) -Golgi Apparatus -Lysosomes -Chloroplasts -Mitochondria |
Algae and Plants Cell Wall | -Composed of Cellulose |
Fungi Cell Wall | -Composed of Chitin (polysaccharide) |
Yeasts | -Composed of Glucan and mannan (polysaccharide) |
Endocytosis | -Process in which plasma membrane encircles particles outside of cell. |
Phagocytosis | -Pseudopods engulf particle -Used by white blood cells |
Pinocytosis | -Small drops of fluid are brought into the cell |
Metabolism | -Refers to all chemical reactions that occur within a living organism |
Catabolic Metabolism | -Degradative reactions that release energy by breaking down large, complex molecules into smaller ones -Often involve hydrolysis, breaking bonds with water |
Anabolic Metabolism | -Biosynthetic reactions that build large complex molecules from simpler ones -Require energy and often involve dehydration synthesis |
Enzymes | -Protein molecules that catalyze chemical reactions -Highly specific and usually catalyze only one of a few closely related reactions -Extremely efficient; speed up reaction up to 10 billion times more than without enzyme |
Turnover Number (Enzymes) | -Number of substrate molecules an enzyme molecule converts to product each second -Ranges from 1 to 500,000 |
Energy of Activation | -The amount of energy required to trigger a chemical reaction |
Enzyme Components | -Some consist of only proteins -Others have a protein portion (aponenzyme) and nonprotein (cofactor) |
Holoenzyme | Aponenzyme + Cofactor |