Microbial Cell Growth & Contributions Flashcards
T or F: Bacterial Media contains nutrients; glucose
True
T or F: Nutrient agar consists of essential nutrients that support the growth of bacteria
True
T or F: A single bacteria cell has 55% carbon, 17% oxygen, 13% nitrogen, 8.2% Hydrogen, 2.5 phosporus, 1.8% sulfur, <0.01 selenium
False, carbon is only 50%
T or F: When bacteria eats the nutrient in the agar, it multiples
True
T or F: Carbon has the highest contribution in bacteria cell
True
T or F: Protein is the secondary contributor of macromolecules in a composition of a cell
False, protein is the primary contributor
It breaks down glucose molecules into ATP to get energy to replicate and produces energy
Catabolism
It builds up molecules to have new set of cells but loses energy; uses energy
Anabolism
Cell’s chemical formula: ???
CH2 O0.5 N0.15
single cell splits into two equal cell
Binary fission
asexual reproduction where a part of the cell is pinched off where a daughter cell may arise
Budding
asexual reproduction, for dispersal and survival
Spores
Duplication of cell
Logarithmic phase
Rapid increase curing a constant time interval
Exponential growth
adaptative phase where synthesis of RNA, enzymes and essential metabolites not found in the environment are produced, cells are adjusting to the culture medium (pH, tempt., O2 conc.) and damaged cells are undertaking repair
Lag Phase
Also called log phase, cell undergo division (doubling of cells = rapid growth). It is the stage where cells are healthiest
Exponential Phase
No increase or decrease in cell number, cells try to adapt to starvation, plasma membrane becomes less fluid and permeable, nucleoid condenses, DNA with binding proteins for preservation. The stage where secondary metabolites are produced
Stationary Phase
Cell number decreases in a fast rate , lack of nutrients and accumulation of toxins or by products. Cells break open or lyse and spill their contents, some try to mutate or adapt for survival
Death Phase
Essential for growth and reproduction
Primary Metabolites
Used for protection
Secondary metabolites
T or F: All bacteria have the same death phase
False
It uses the petroff-housser counting chamber
Direct microscopic counting
Quantifies the growth of bacteria, plating counting number of bacterias. For ex., serial dilution, spread plate, pour plate
Viable count
Measurements are made in spectrophotometer. In this method it measures incident light unscattered by cells in suspension and gives readings in optical density units
Turbidimetric method
Microbes that can survive in low temperature optima of 15°C or lower
Psychrophiles
MOS that grow in 0°C but have optima of 20-40°C
Psychrotolerant
MOS that grow in midrange temperature optima
Mesophiles
MOS that grow in high temperature optima exceeding 45C
Thermophiles
MOS that grow in very high temperature optima exceeding 80C
Hyperthermophiles
MOS that grow below pH 5.5
Acidophiles
MOS that grow in pH 5.5 -7.9
Neutrophiles
MOS that grow above pH 8
Alkalinophiles
water diffuses from regions of high water conc. (low solute conc.) to regions of lower water conc. (higher solute conc.)
Osmosis
marine organisms; if placed in hypertonic solution, it will not shrink and is resistant of high salt conc.
Halophiles
can tolerate in high salt conc. but optimum growth is at non salty environments
Halotolerant
can tolerate 15-30% NaCl
Extreme halophiles
organisms that can live in environment; With high sugar solute
Osmophiles
able to grow in very dry environment
Xerophiles
Requires O2 to grow
Obligate aerobes
Not required but grows better with O2
Falcutative aerobes
O2 required but at levels lower than atmospheric
Microaerophilic aerobes
O2 not required but can tolerate
aerotolerant
fears O2; will die
Obligate anaerobe
a high-energy form of oxygen in which the outer shell electrons surrounding the nucleus became highly reactive and can carry out spontaneous and undesirable oxidations
Singlet Oxygen
Yellow to orange pigment; can counteract singlet O2
Carotenoids
strong oxidizing agents; causes rusts in metal
Superoxide anion
damage cell component, not as toxic as O2- and H2O2
Hydrogen peroxide
Strong radical; peroxidase enzyme like catalase -> will convert deadly hydrogen peroxide into water and NAD+
Hydroxyl radical
converts singlet oxygen to a lesser form; good enzyme
Superoxide dismutase
