Key Area 2.6 Flashcards
Why are microorganisms ideal for research and industrial use
- Easy to cultivate
- rapid reproduction
- their food is cheap or a waste product
- their metabolism can be altered easily
State 3 examples of culturing conditions that can be altered and state how they can be altered
PH - by buffers or addition of acids or alkalis
Oxygen levels - aeration (bubbling O2 through solution)
Temperature - outer jacket filled with water
What materials do microbes need to grow
An energy source
Supply of raw materials
Why are microorganism useful to humans
They make a wide range of metabolic products
E.g. Insulin
Where would the culture of microorganism be used
Research and industry
What are microbes grown on and why
Culture media, it supplies all essential nutrients
Why must the culture environment be sterile
Avoid contamination from other microorganisms
List 2 some aseptic techniques
- wash hands
* clean worktops
Name 3 potential sources of energy for microbes being grown in a culture
- carbohydrates
- glucose
- light
Name 2 raw materials microbes could use in a culture
- amino acids
* nucleotides
Name and describe the different types of cell counts
- viable cell count - counting only living cells
* total cell count - counting the living and dead cells
State the 4 phases of growth shown on a bacterial growth curve
Lag
Exponential
Stationary
Death
Describe the lag phase
Where microorganisms adjust to the conditions of the culture
They produce enzymes that breakdown substrate
No cell division at the stage
Describe the exponential phase
Rate of growth is at its highest at this stage
Stationary phase
The culture medium becomes deleted and secondary metabolites are produced
The rate of production of new cells to equal to the death of old cells
Describe the death phase
Lack of substrate and the toxic accumulation of metabolites causes death of cells
Death rate of cells is greater than the production rate
What is the difference primary and secondary metabolites
Primary: related to the synthesis of cell materials (produced in exponential phase)
Secondary: no direct relationship to cell growth or synthesis of cell materials but may confer a evolutionary advantage (produced in stationary phase)
State a secondary metabolites and it’s benefit to humans
Insulin
Helps treat diabetes
What is the function of each of the following in a metabolic pathway:
1) precursors
2) inhibitor
3) inducer
1) large quantities of an earlier metabolite is supplied to ensure the continuous supply of another metabolite in a later stage
2) induces the formation of a key enzyme to ensure a continuous supply of a metabolite
3) reduces the inactivity it an enzyme to avoid the breakdown of a metabolite allowing it to accumulate
Where do microorganism get their energy source and raw materials from
Growth medium
