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105 Cards in this Set
- Front
- Back
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Define nutrition.
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A substance that provides nourishment essential for growth and the maintenance of life.
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Define essential nutrient.
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a nutrient required for normal body functioning that either cannot be synthesized by the body at all, or cannot be synthesized in amounts adequate for good health (e.g. niacin, choline), and thus must be obtained from a dietary source.
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Define macronutrients.
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needed in larger quantities
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Define micronutrient.
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needed in larger quantities
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Define inorganic nutrient.
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a substance or nutrient that does not carbon or hydrogen.
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Define organic nutrient.
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a substance or nutrient that contains carbon or hydrogen.
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What portion of water is a microorganism?
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80-90 percent
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What is the most abundant component of cells (after water)?
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hydrogen
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What elements make up 96% of dry weight of a cell?
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CHONPS carbon, hydrogen, oxygen, nitrogen, phosphorus, sulfur
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How does a heterotroph get its carbon?
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Organic carbon by eating/consuming other living things.
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How does an autotroph get its carbon?
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Accessing it from inorganic sources.
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Where do we get our nitrogen?
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Air and food
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What can take nitrogen gas from air and convert it into forms used by other creatures?
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Bacteria
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Where do we get our oxygen?
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Air
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What do we use hydrogen for?
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mostly as water
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What are sources of sulfur?
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hydrogen sulfide (H2S), sulfur, and thiosulfate (S2O32-).
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What are growth factors.
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Growth factors are organic compounds such as amino acids (def), purines (def), pyrimidines (def), and vitamins (def) that a cell must have for growth but cannot synthesize itself
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What are the life requirements of prokaryotes?
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Temperature, pH, Oxygen or not, solute concentration, nutritional requirements.
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What is a fastidious organism?
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require specialized environments due to complex nutritional requirements.
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What are the 4 nutritional categories of organisms?
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"1. Photoautotrophs 2. Photoheterotrophs 3. Chemoautotrophs or Lithotrophs (Lithoautotrophs) 4. Chemoheterotrophs or Heterotrophs
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What is carbon source and energy source of chemoautotrophs?
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Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.
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Give examples of chemoautotrophs.
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extremophiles, usually bacteria.
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Give examples of photoheterotrophs.
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plants
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What is carbon source and energy source of chemoheterotrophs?
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Mostly autotrophs.
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Give examples of chemoheterotrophs.
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People, animals - anyone that can’t make their own food.
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Discuss metabolism of photoautotrophs.
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able to harvest the carbon they need directly from light.
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Discuss metabolism of chemoautotrophs.
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Chemoautotrophs use inorganic energy sources, such as hydrogen sulfide, elemental sulfur, ferrous iron, molecular hydrogen, and ammonia.
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Define saprobe.
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An organism that derives its nourishment from nonliving or decaying organic matter.
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Define parasite.
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an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment.
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What is the difference between obligate parasite and facultative parasite.
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An obligate parasite is a parasitic organism that cannot complete its life cycle without dependence on its host. A facultative parasite is an organism that may resort to parasitic activity, but does not absolutely rely on any host for completion of its life cycle.
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List various environmental factors that influence microbial growth.
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Temperature, atmosphere (gas requirements), pH, Osmotic pressure, Each organism has an optimum and an acceptable range. Radiation, hydrostatic pressure.
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What are the 3 cardinal temperatures?
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minimum (lowest at which organism grows), Maximum (highest), Optimal (for most growth)
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Define Psychrophile.
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“cold lovers” - optimum temperature < 15 degrees C. Grow at 0 degrees C but not above 20 degrees C.
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Define psychrotroph.
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Grow in refrigerator but optimum > 20 C
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Define Mesophile.
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Optimum temperature is between 20 and 40 degrees C.
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Define Thermophile.
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Heat lovers - optimum temperature over 40 degrees C.
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What are atmospheric requirements?
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Atmospheric gases, temperature, pH, pressure,
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Define obligate aerobe.
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Requires oxygen for growth.
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Define obligate anaerobe.
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Dones not require oxygen, oxygen is toxic.
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Define facultative anaerobe.
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Can have O2 or none.
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Diefine microaerobphile.
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Requires less oxygen, prefers increased carbon dioxide, capnophiles.
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Define aerotolerant.
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Does not use oxygen but can survive in its presence.
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Define Neutrophiles
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pH 6-8
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Define Acidophiles.
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pH 0-4.5
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Define Alkalophiles.
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pH 7-10
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What is a barophile?
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An organism that can tolerate extremely high pressures.
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Define symbiosis.
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Two organisms living together.
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What types of symbiosis are there?
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Mutualism (both benefit, obligatory), Commensalism (one benefits, one neutral), Parasitism (one benefits, one harmed), Synergism (free-living - when they live together both benefit, but they don’t need each other), Antagonism (competition between organism, one secretes substances against the other.
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What is a bacteriocins?
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Toxic proteins secreted by Gram-bacteria.
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What is a Biofilm?
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Community of microbes. Able to communicate and act as a group - chemical signaling. Initial organisms secrete inducer molecules. More cells attach until “quorum” reached, Inducer molecules allow film to function as a unit. Breakdown of complex molecules by saprobes. Colonization of body by organisms, colonization of medical surfaces (big problem). May contain several species. Allows for genetic exchange.
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Discuss bacterial growth.
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Reproduction is by binary (transverse) fission. Generation time 30-60 minutes is average 5 minutes to several days. Doubles size first.
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What are ways to measure microbial growth in a liquid broth?
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Turbidity - can tell visually or with a spectrophotometer to see how much light passes through.
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List some ways to measure microbial growth.
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Turbidity, Direct cell counts (pour plates)
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Define metabolism.
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Totality of all chemical reactions - breaking down and building up.
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Define catabolic reaction.
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Degradation - breaking down. Utilizes energy in something.
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Define anabolic reaction.
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Synthesis - building things. Costs but creates value.
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Anabolism requires _________.
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Energy.
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Define enzyme.
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A catalytic protein. Speeds up reaction. Lowers activation energy.
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List the types of enzymes.
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Simple enzyme, conjugate enzyme, Holoenzyme = apoenzyme + cofactor.
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Define coenzyme.
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An organic coenzyme - something that can join with protein to make it an active enzyme.
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Define inorganic.
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Lacks carbon and hydrogen.
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Coenzymes are usually provided by ________.
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Vitamins.
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Define exoenzyme.
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secreted and act outside the cells.
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Define endoenzyme.
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Retained - acts inside cell.
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Define constitutive enzymes.
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Always present, constant amount.
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Define regulated enzymes.
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Produced only if substrate is present.
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Discuss synthesis reaction.
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Anabolism. Requires enzymes and energy to form bonds. Usually liberate water condensation.
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Discuss degradation reaction.
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Catabolism. Require enzymes to break bonds and liberate energy.
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OIL RIG
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Oxidation is lost. Reduction is gained.
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What is the role of enzymes in disease?
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Digest tissues, inactivate antibiotics
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Discuss enzyme sensitivity.
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Anything that affects protein structure. pH, Temperature,
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How are enzymes controlled in Direct control?
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Direct - enzyme already produced, control enzyme, competitive inhibition, Molecules with structure similar to substrate occupies active site on enzyme, Noncompetitive inhibition - Enzyme has two binding sites, active site and regulatory site, binding to regulatory site inactivates enzyme. Feedback inhibition (endproduct of pathway inhibits enzyme pathway)
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How are enzymes controlled in indirect control?
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Control enzyme synthesis - enzyme repression (endproduct of pathway stops gene expression), Enzyme induction (presence of substrate causes gene to be expressed).
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Discuss energy formation and utilization.
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Energy in cell in electrons involved in chemical bonds. Intact bonds represent potential energy, breaking bonds releases kinetic energy - endergonic reactions require (energy anabolism), exergonic reactions release energy (catabolism)
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“Who” is oxidized and “who” is reduced?
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Energy donor, energy acceptor.
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Molecules that are rich in hydrogen are rich in _______.
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energy.
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Define dehydrogenation.
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Moving hydrogen from one molecule to another.
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What is the only source of living human cells can use to do work?
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ATP
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What do electron carrier molecules do?
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They repeatedly release and accept electrons. Most carriers are coenzymes NAD+ and FAD, At the end of the chain is final electron acceptor, accepts electron and doesn’t release it.
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How does ATP become ADP?
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It phosphorylates.
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What manages energy for every cell?
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ATP
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What is the primary energy molecule stored in cells?
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Glucose.
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What are different catabolic actions that can generate ATP?
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Glucose primary energy molecule, aerobic respiration (phosphogluconate pathway), anaerobic respiration (fermentation).
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What is the most efficient method for regenerating ATP?
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Glycolysis, Krebs cycle, electron transport chain.
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What is the path/order for glycolysis?
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Gulcose-6-PO4 (phosphate) > 2 pyruvate + 2 ATP + 2NADH
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What is substrate level phosphorylation?
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When the phosphate is taken from glucose and added to ADP to make ATP.
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What is the path/order for Krebs Cycle? Tricarboxylic Acid Cycle
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Pyruvate > Acetyl CoA + CO2 + NADH -- Acetyl CoA > 3CO2 + ATP + FADH2 + 3NADH
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What are the only things that continue to final electron transport chain?
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NADH & FADH2`
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Discuss the electron transport system.
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Series of carrier molecules (each one in the line has a little stronger pull), cytochromes (molecule carrier), and Electron transport steps, and chemiosmosis.
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What is the path/order for Electron transport system?
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10 NADH + 2 FADH2 + O2 . 34 ATP + 6 H2O
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What is the end waste product of the electron transport system?
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H2O
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Define Chemiosmosis?
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Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient.
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Discuss the phosphogluconate pathway.
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“Hexose Monophosphate Shunt” Anaerobic utilization of glucose and other hexoses, also allows for use of pentoses, electron carrier NADP, Common pathway in the heterolactic fermentative bacteria.
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What is the only anaerobic step of energy production?
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Glycolysis.
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Discuss anaerobic respiration.
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Glycolysis; Kebs cycle (bypasses steps using O2); Electron transport system (uses different cytochromes); Final electron acceptor - oxygen (containing inorganic salt); Produces > 2ATP but < 34ATP
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What organisms carry out anaerobic respiration?
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Mostly bacteria.
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Discuss fermentation.
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Incomplete oxidation of glucose, oxygen is absent, pyruvate reduced (acid fermentation); Alcohol fermentation (pyruvate > acid > Alcohol); 2 ATP (glycolysis), final electron acceptor is organic molecule.
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What is the path/order for acid fermentation?
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Pyruvate + NADH > NAD + acid
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What are the major catabolic pahtways?
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Aerobic respiration (glucose, steps - glycolysis, Krebs cycle, ETS. O2, 36 ATPS); Anaerobic Repsiration (glucose, steps - glycolysis, Krebs cycle, ETS, Inorganic, 3-32 ATPS); Fermentation (Glucose, steps - glycolysis, fermenation, Organic, ATPS)
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What is anabolism?
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The building up (Biosynthesis).
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What are things that a cell has to build?
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Proteins, nucleic acids, lipids, carbohydrates.
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Define gluconeogenesis.
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Forming new glucose from non-carbohydrates.
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Discuss carbohydrate synthesis.
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Monosaccharides from nutriets, synthesize sugars from other things.
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Discuss protein synthesis.
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amino acids from nutrients. Synthesize amino acids. Protein synthesis major anabolic process.
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Discuss nucleic acid synthesis.
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The body can build DNA, etc. from things present in environment.
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