Micro Chpt. 7 Microbial Nutrition – 2013 – Flashcards
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| The source of the necessary elements of life is ? |
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| An inoorganic environmental reservoir. |
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| An organism that can synthesize all its required organic components from CO 2 using energy from the sun is a ? |
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| Photoautotroph. |
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| Chemoautotrophs can survive on ___ alone. |
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| Minerals and CO 2 |
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| Which of the following statements is true for all organisms? |
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| The require inorganic nutrients. |
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| A pathogen would most accurately be descibed as a ? |
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| Parasite. |
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| Which of the following is true of passive transport? |
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| It requires a gradient. |
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| A cell exposed to a hypertonic environment will ___ by osmosis ? |
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| Lose water. |
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| Psychrophiles would be expected to grow ? |
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| At refrigeration temperatures. |
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| Superoxide ion is toxic to strict anaerobes because they lack ? |
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| Dismutase. |
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| In a viable plate count, each ____ represents a _____ from the sample population ? |
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| A.) Colony B.) Cell |
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| True/False Active transport of a substance across a membrane requires a concentration gradient? |
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| False Active transport of a substance across a membrane requires energy. |
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| An organic nutrient essential to an organism's metabolism that it cannot synthesize is called a growth factor? |
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| True |
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| True/False Biofilms consist of multiple species of bacteria? |
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| False Some biofilms consist of multiple species of bacteria. |
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| An obligate halophile is an organism that requires high osmotic pressure? |
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| False An obligate halophile is an organism that requires high salt concentration. |
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| An anaerobe can grow with or without oxygen ? |
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| False A facultative anaerobe can grow with or without oxygen. |
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| Chemical analysis of microbial cytoplasm: List Chonps whitch constitute 96% elements |
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| C=Carbon H=Hydrogen O=Oxygen N=Nitrogen P=Phosphorus S=Sulfur |
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| Carbon sources - organic form? |
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| HETEROTROPH OBTAIN CARBON IN A ORGANIC FORM (NUTRITIONALLY DEPENDEDNT ON LIVING THINGS Autotroph (self feeder) Uses inorganic CO2 as its carbon source (not nutitionally dependent on other living things) |
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| Hydrogen-in several inorganic compounds Performs overlapping roles in the biochemistry of cells-----Functions |
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| -maintaining pH forming hydrogen bonds between molecules -serving as the source of free energy in ocidation-reduction reaction of respiration |
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| Oxygen is a major component of? |
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| -organic compounds -also makes a common component of inorganic salts |
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| Oxygen makes up what % of the atomosphere |
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| 20% |
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| Nitrogen sources N2- pRIMARY NITROGEN SOURCE FOR Some bacteria and algae utilize? |
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| heterotrophsproteins, DNA, RNA Some bacteria and algae utilize INORGANIC NITROGENOUS NUTRIENTS |
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| Small number can transform N2 into- |
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| unsable compounds through nitrogen fixation |
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| Regardless of the intial form of nitrogen, must be converted into ? |
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| NH3 (the only form that can be directly combined with C to synthesize amino acids and other compounds |
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| What is the main inorganic source of phosphorus? |
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| is phosphate (PO4)3- Derived from phosphoric acid found in rocks and oceanic mineral deposites |
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| Phosphorus is a key component in Found in? |
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| nucleic acids found in ATP phosphlipids in cell membranes and coenzymes |
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| Sulfur sources |
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| widley distributed throughout enviroment in mineral form essential component of some vitamins amino acids- methionine and cysteine |
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| Describe nutrients important in microbial metabolism Potassium |
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| Potassium-protein synthesis and membrane function |
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| Describe nutrients important in microbial metabolism Sodium |
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| sodium-certain types of cell transport |
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| Describe nutrients important in microbial metabolism Calcium |
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| Calcium-stabilzer of cell walls and endosphores |
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| Describe nutrients important in microbial metabolism Magnesium |
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| magnesium- components of chlorophyll and stabilizer of membranes and ribsomes |
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| Describe nutrients important in microbial metabolism Iron |
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| iron-important component of cytochrome proteins |
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| Describe nutrients important in microbial metabolism Zinc |
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| zinc-essential regulatory element for eukaryotic genetics and binding factors for enzymes |
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| WHat other nutrients are needed by some microbes in small amounts but nit in others |
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| cooper,cobalt, nickle, molybdenum, manganese, silocon, iodine and boron |
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| give growth factor definition and example? |
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| an organic compound such as amino acid, nitrogenous base, or vitamin that cannot be synthesized by an organism and must be provided as a nutrient For example - many cells cannot synthesize all 20 amino acids so they must obtain them from food (essential amino acids) |
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| Autotroph |
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| self feeders use carbon dioxide |
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| heterotroph |
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| other feeders use organix compounds |
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| Energy sources- chemotroph use? |
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| chemotroph use organic molecules |
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| energy source- phototroph use? |
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| phototroph use light |
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| Energy sources- Lithotroph use? |
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| Lithotroph use? inorganic molecules like H2S |
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| List three energy sources |
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| chemotroph phototroph lithotroph |
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| Where do obligate saprobes exist? |
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| strictly on dead organic matter in soil and water |
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| Saprobes free-living microorganisms Describe Decomposes |
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| Describe: have rigid cell wall, so they release enzymes to the extracellular enviroment and digest food particles into snaller molecules decomposers of plant litte, animal matter and dead microbes |
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| ectoparasites |
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| live on body |
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| endoparasites |
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| live in organs and tissues |
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| intracellular parasites |
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| live within cells |
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| obligate parasites |
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| unable to grow outside of a living host |
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| parasites derive fromalso called? |
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| Parasite derive nutrients from the cells or tissue of a host -also called pathogens because they cause damage to tissues or even death |
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| Describe nutrient transport? |
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| most nutrients are polar Do not cross the membrane alone requires a carrier need to concentrate essential nutrients require energy |
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| describe diffusion |
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| when atoms and molecules move in a gradient from an area of higher concentration to an area of lower concentration will eventually evenly distribute the molecules simple or passive diffusion is limited to small nonpolar molecules or lipid soluble molecules |
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| osmosis- |
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| diffusion of water through a selectively permeable membrane |
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| Describe the movement of water through the selective membrane? |
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| is selectively permeable; allows free diffusion of water but can block other dissolved molecules when solute is not diffusible, water will diffuse at a fast rate from the side that has more water to the side that has less water |
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| Isotonic |
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| the enviroment is equal in solute concentration to the cell's internal enviroment. No net change in the cell volume. generally the most stable enviroment of cells |
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| Hypotonic |
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| The solute concentration of the external enviroment is lower than that of the cells internal enviroment net direction of osmosis is from the hypotonic solution into the cell cells without cell walls swell and can burst |
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| Hypertonic |
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| the enviroment has a higher solute concertration than the cytoplasm will force water to diffuse out of a cell cell will shrink |
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| Two types of passive transport |
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| Diffusion and osmosis |
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| Describe active transport |
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| Protein carrier and energy required movement against the gradient |
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| endocytosis |
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| particles are engulfed |
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| pinocytosis |
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| liquids entering the cell |
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| phagocytosis |
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| process carried out by white blood cells to engulf cells or particles |
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| exocytosis |
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| package and release of substances from a cell |
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| metabolism Functions of metabolism |
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| all chemical reactions and physical working of the cell functions of metabolism: assembles smaller molecules into larger macromolecules needed for the cell (anabolism) Degrades macromolecules into smaller molecules and yields energy (catabolism) engery is conserved in the form of ATP or heat |
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| anabolism (biosynthesis) |
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| Any process that results in synthesis or cell molecules and structures (usually requires energy input) |
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| catabolism |
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| The breakdown of bonds of larger molecules into smaller molecules (often release energy) |
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| What are catalysts? |
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| Enzymes |
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| Catalysts |
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| chemicals that increase the rate of a chemical reaction without becoming part of the products or being consumed in the reaction |
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| How do enzymes work? |
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| energy of activation. The amount of energy which must be overcome for a reaction to proceed. an enzyme promotes a reaction by serving as a physical site upon which the reactant molecules (subtract) can be positioned for various interactions |
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| Enzyme -Substrate interactions? |
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| for a reaction to take place, temporary enzyme -substrate union must occur at the active site lock and key fit bonds are weak and easy reversible |
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| Constitutive enzyme- |
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| always present and in relatively constant amounts |
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| regulated enzymes |
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| production is either induced or repressed in response to a change in the constration of the substrate |
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| Characteristics of enzyme- |
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| -most composed of protein -act as a organix cataylst to speed up the rate of cellular reactions have unique characteristics of shape, and function -greatly affected by temperature and pH can be regulated by feedback. |
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| One of the most important components of coenzymes? |
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| Vitamins |
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| Describe coenzymes |
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| -organic compunds that work in conjunction with a apoenzyme to perform a necessary alteration of a substrate -Removes a chemical goup from one substrate molecule and adds to another. |
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| Describe Metallic cofactors? |
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| Include Fe; Cu, Mg, Zn, Co,Se activate enzymes, help bring the active site and substrate close together, and participates directly in chemical reactions with the enzyme-substrate complex |
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| Constitutive enzymes |
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| always present and in relatively constant amounts |
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| regulated enzymes |
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| production is either induced or repressed in response to a change in concentration of substrate |
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| Fungal infections in humans are called |
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| mycosis |
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| Toxoplasma gondii is which type of cell? |
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| Eukaryotic |
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| Differential staining of bacterial membranes is considered _______Classification |
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| Phenetic |
