Lecture 3 Flashcards
HD
How is bacterial growth defined?
An increase in cell number
What are the 2 types of Bacterial Growth?
Anabolic and Catabolic
Anabolism grows from what to what?
Small to large
Catabolism grown from what to what?
Large to small
What is binary fission?
When a cell divides into 2 new cells
What is generation time?
Time required for cells to double structural components
What is exponential growth?
When the cells double per unit time
What are 2 approaches to the study of growth under controlled conditions?
Batch Culture & Continuous Culture
Difference between batch culture and continuous culture?
Batch - fixed substrate is added - Continuous a continuous amount of growth medium
List the 4 phases of growth
- Lag
- Exponential
- Stationary
- Death
Main Reason for the lag phase to occur?
New conditions - adaptation
Growth will remain in the lag phase until the population reaches…
10 to the 6 cells/ml
2 reasons for stationary phase
Carbon and energy source
Nutrients are used up
What is endogenous metabolism?
Growth on dead cells
Which is slower death phase of exponential phase?
Death phase
What are capnophiles?
Microbes that grow better at high CO2 concentrations
What are porins?
Part of the outer membrane - allows the passage of molecules
What are autolysins?
Enzymes that create small openings in the macromolecular structure of the wall
What is the periplasm?
Fluid filled space between the outer membrane and the plasma membrane.
What is the most important differential stain used in bacteriology?
Gram Stain
Two major groups of Gram Staining?
Gram-positive and Gram Negative
Colour of gram-negative bacteria at end of Gram Staining?
Red - pores increase so the violet colour leaves
Colour of Gram-Positive Bacteria at end of Gram Staining?
Violet - Pores shrink so the colour stays
True or false - gram staining must be performed on cultures less than 24hrs old?
True