How do prokaryotes generally multiply?
binary fission
What is binary fission?
When the cell increases in size and doubles its components, it
divides. The cell divides into two, then those cells divide into four.
The time it takes for a population to double in size is called
generation time
Prokaryotes that can attach to surfaces nd live in polymer-encased
communities are called
Biofilms
How are Biofilms formed?
Prokaryotic cells move to a surface and adhere where they multiply
and release polysacharrides, DNA and hydrophilic polymers
Why are infections due to biofilm hard to treat?
The microbes within the extracellular polymeric substance(EPS) often
resist the effect of the antibiotics. The EPS serves as a protective layer
What gives the biofilm a slimy appearance?
The extracellular polymeric substance
What are the benefits of Biofilms?
They help in bioremediation which uses microbes to degrade harmful chemicals
A population that has descended from a single cell is called
pure cultures
Why are pure cultures used?
to easily identify and study activities of particular species
Procedures to minimize the possibility of introducing another
bacteria by accident.
Aseptic Techniques
The medium the cells are grown on or in is called
culture
A single prokaryotic cell supplied with the right nutrients and
conditions will multiply on solid medium in a limited area to form
colonies
A mass of cells
Colony
A polysacharide extracted from marine plants that is used to solidify culture
Agar
The simplest and common way to isolate a prokaryotic cell
Streak plate method
What is the goal of the streak plate method?
To reduce the number of cells being spread with each successive
series of streak to make sure we get a distinct isolated cell.
Bacteria and Archea are typically grown on agar plates or tubes or
flask of broth. This are considered closed systems or batch cultures. Why?
Nutrients are not renewed nor wastes are removed
In what system does the population increase in distinct pattern of
stages and then declines
Closed
What type of system is it when cells are maintained in a state of
continuous growth with continuous addition of nutrients and removal of
waste products?
open
Lag Phase,Log Phase,Stationary phase,Death Phase,Phase of Prolonged
death are stages of
Growth curve
During this phase on the growth curve, cells begin to synthesize
enzymes required for growth
Lag Phase
paDuring this phase on the growth curve, cells divide at a constant
rate. This is where generation time is measured
Log Phase
At what stage on the growth curve are Primary metabolites made?
Log Phase
What are Primary Metabolites?
small molecules made by cells during log phase
At what stage are secondary metabolites made?
Stationary Phase
What are secondary metabolites?
When compounds begin to accumulate at the stationary and are used for
other purposes other than growth
What is the most valuable secondary metabolite made?
antibiotics
What phase on the growth curve: When the nutrient level is too low to
sustain growth. The Some cells are dying while others are multiplying
at a constant rate.
Stationary Phase
What phase on the growth curve: When a fraction of cells survive the
death phase and are able to multiply for a short period of time. These
survivors die
Phase of prolonged death.
A device that continually drips fresh medium into broth culture
contained in a chamber. This device influences the continuous growth
of microbes
Chemostat
In what domain of Prokaryotes do these microbes that live in harsh
environmental conditions belong to:
Archea
Microbes that can live in harsh environmental conditions are called:
Extremophiles
What are 4 environmental factors that affects microbial growth?
Temperature
pH
atmosphere
water availability
Based on temperature requirements: What do you call the type of
microbes that have optimum growth between -5 and 15 degrees .? these
microbes can grow in the cold artic
Psychrophiles
Based on temperature requirements: What do you call the type of
microbes that have optimum growth between 20 and 30 degrees .? They
cause spoilage in refrigerated food.
Pyschrotrophs
Based on temperature requirements: What do you call the type of
microbes that have optimum growth between 25 and 45 degrees .? these
microbes can adapt to growth on human body and inhabit soil.
Mesophiles
Based on temperature requirements: What do you call the type of
microbes that have optimum growth between 45 and 70 degrees .? these
microbes can grow in hot springs
Thermophiles
Based on temperature requirements: What do you call the type of
microbes that have optimum growth at 70 degrees or greater.? these
microbes can grow in the hydrothermal vents of the ocean and are
usually microbe that belong to the archea domain
Hyperthermophiles