Fundamentals Of Microbiology Flashcards
What are 7 characteristics distinguishing organisms?
Responsiveness-to the environment
Reproduction-allows adaption through genetic material transfer
Growth-in size and numbers
Metabolism-produces ATP
Movement-from worse to better conditions
Excretion-of waste products of metabolism
Cell- common physical unit where functions occur
What are the 2 basic requirements of all living cells?
Catabolism+anabolism=metabolism
Describe simply:
Catabolism=cellular energy production (ATP)
Complex molecules->
exothermic energy release->
Simple molecules
Describe simply:
Anabolism=
assimilation/growth and repair
External C substrate->
Endothermic reaction->
New cellular material
Catabolic pathways . . .
Produce simple waste products and energy which is conserved as ATP temporarily
Anabolic pathways . . .
Utilise ATP for the synthesis of monomeric compounds needed for the making of small molecules in cells. (Carbs,lipids,vitamins)
Microorganism classification
Autotrophs(self feeders)
(Photo)autotrophs - light;algae
(Chemo)autotrophs-inorganic compounds;iron,sulfur
Heterotrophs (other feeders)
(Photo)heterotrophs-light;purple/green non sulfur bacteria
(Chemo)heterotrophs-inorganic compounds;all animas,fungi
Cell division of prokaryotes
Duplication of chromosomes
Continued growth of cell
Division into two cells
Difference between types of eukaryotic cell division?
Mitosis - Asexual -concerned with competitive reproduction
Meiosis-sexual-survival of host genes
Only difference is after chromosomes double, the cell split in 2 X and then 4 I in meiosis.
How O2 affects growth of bacteria
Obligate aerobes- NEED O2(eukaryote)
Facultative anaerobes-prefer O2, but switch to alternative electron acceptors when deficient
Obligate anaerobes-O2 is poisonous to them
Effect of temperature on Growth
Optimum temp in °C
Pyschrophile- 0-25
Mesophile 30-45
Thermophile 55-75
Effect of Ph on Growth
Acidophiles prefer 3
Neutrophiles prefer 7
Alkaphiles prefer 9-10
Effects of water on growth
Cells are sensitive to changes in osmotic potential
HIGH OP=low solute conc.=high kinetic energy
Low OP=high solute conc.=low kinetic energy
Solutes in cytoplasm maintain OP “below habitat”
Describe the different osmotic potential states
Hypotonic-water flows into cell, low external salt conc
Isotonic-same inside and out
Hypertonic-water leaves cell,high external salt conc
Water seeks to move to the place with high salt conc, in an effort to make the system isotonic
Summary of Bacteria
Use of organic and inorganic carbon sources for energy as growth
Algae and Cyanobacteria use sunlight for energy
Bacteria can use alternative electron acceptors to O2 for metabolism
Sensitive to environmental conditions
