MICROPARA LEC REVIEWER

• NUTRITION- process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities
• Essential nutrients - must be provided to an organism
• • Micronutrients or trace elements - required in small amounts; involved in enzyme function and maintenance of protein structure
• Two categories of essential nutrients: macronutrients and micronutrients
• • Organic nutrients - contain carbon and hydrogen atoms and are usually the products of living things
• • Inorganic nutrients - atom or molecule that contains a combination of atoms other than carbon and hydrogen
• • Heterotroph - must obtain carbon in an organic form made by other living organisms such as proteins, carbohydrates, lipids, and nucleic acids
• • Autotroph - an organism that uses COz, an inorganic gas as its carbon source
  • Not nutritionally dependent on other living things
• • Growth factors must be provided as a nutrient
• • Chemotroph - gain energy from chemical compounds
• • Phototrophs - gain energy through photosynthesis
• • Chemoautotrophs (lithoautotrophs) survive totally on inorganic substances
• • Methanogens, a kind of chemoautotroph, produce methane gas under anaerobic conditions
• • Saprobes: free-living microorganisms that feed on organic detritus from dead organisms
• • Parasites: derive nutrients from e host
• If an organism is degrading large organic molecules to get both carbon and energy, it would be best described as a chemoheterotorph
• Passive Transport- does not require energy and is driven by concentration gradient.
• • Active transport - requires energy and carrier proteins; gradient independent
• water difuses out of the cell and shrink the cell membrane away from the cell wall, The process os known as: plasmolysis
• blast- Is the net diffusion of water is into the cell: this swels the protoplast and plushes it tightly.
• • Endocytosis: bringing substances into the cell through a vesicle or phagosome
• • Phagocytosis ingests substances or cells
• • Pinocytosis ingests liquids
• If a cell is in a concentrated glucose solution and the

  glucose is moving into the cell through a carrier protein, this would be an example of - Facilitated diffusion
• • Environmental factors -affect the function of metabolic enzymes
• • Factors include:
  • Temperature
  • Oxygen requirements
  • рН
  • Osmotic pressure
  • Barometric pressure
• • Minimum temperature - lowest temperature that permits a microbe's growth and metabolism
• • Maximum temperature - highest temperature that permits a microbe's growth and metabolism
• • Optimum temperature - promotes the fastest rate of growth and metabolism
• Psychrophiles - optimum temperature below 15°C; capable of

  growth at 0°C
• Mesophiles - optimum temperature 20°-40°C; most human

  pathogens
• Thermophiles - optimum temperature greater than 45°C
• • Aerobe - utilizes oxygen and can detoxify it
• • Obligate aerobe - cannot grow without oxygen
• • Facultative anaerobe - utilizes oxygen but can also grow in its absence
• • Microaerophilic - requires only a small amount of oxygen
• • Anaerobe - does not utilize oxygen
• • Obligate anaerobe - lacks the enzymes to detoxify oxygen so cannot survive in an oxygen environment
• • Aerotolerant anaerobes - do not utilize oxygen but can survive and grow in its presence
• Capnophile - grows best at higher CO, tensions than normally present in the atmosphere