Lecture 4: Flashcards
What is the capsule made of?
Glycocalyx
What is the slime layer made of?
Glycocalyx
Do bacteria demonstrate learning behavior?
Yes!
How much of our cells are actually human?
10%
How much of the genetic material in our body is human?
1%
What does the new view of bacterial biology state?
Bacteria are:
• Highly ordered and dynamic
• Capable of polarizing and differentiation into cell types
• Signal each other to coordinate multicellular actions
• Exhibit learning behaviour – anticipate changes in their environment
(Pavlovian conditioning)
Is it possible to produce synthetic microorganisms?
Yes.
What is the cell wall of a bacterial cell mostly made of?
Peptidoglycan
On average, how many years of life does antibiotics add to a person?
20!
What is the function of bacterial cell walls?
- Rigid macromolecular layer that provides strength to cell
2. Protect cells from osmotic lysis and confers cell shape
How does antibiotics work?
It targets the peptidoglycan cell wall, and the cell explodes from osmotic pressure.
What is transpeptidase?
The enzyme that cross links the peptidoglycan chains to form rigid cell walls.
What two types of cells does a gram test test for?
Gram positive and gram negative.
What type of cell has a very thick layer of peptidoglycan?
Gram positive (dye remains in the gram test).
What is a gram negative cell?
A type of cell that has a thin layer of peptidoglycan between two membranes.
Do bacteria operate in a coordinated or random fashion?
Coordinated.
What are the three parts that make up the Flagella?
The long filament, the hook and the basal body.
What is the long filament of a flagella?
The part that extends out and operates like the blades of a rotor.
What is the hook of a flagella?
A curved section which connects the filament to the cell wall.
What is the basal body of a flagella?
The ‘gears’, for coordinating speed and rotation.
As bacteria are too small to sense spatial gradients, how do they navigate?
They ‘tumble’ and ‘run’, moving forward, sensing concentration (using chemoreceptors), comparing and moving forward again.
What is the main purpose of fimbrae?
Adhesion.
What are fimbrae, and what is another name for them?
They are ‘hairs’ on the surface of bacterial cells with adhesins on the outer ends. These adhesins bind to specific receptors.
What’s the difference between capsules and slime layers?
Capsules are well organised around the cell, whereas slime layers make a random mesh around the cell.
What is an example of asymmetric cell division?
Bacterial endospores
What is the advantage of a bacterial endospore?
They are resistant to heat, harsh chemicals, etc. and can remain dormant for a long time, until conditions are ideal.
What are the protective layers of an endospore?
Exosporium, spore coat, core wall, cortex, and then the DNA.
True or False:
“Bacterial endospores have a very high water content”
FALSE. Bacterial endospores have low water content.
