Microbiology Concepts Review

Microbial Secretion Systems

Matching

Which secretion system:

• Moves protein from the periplasmic space to the exterior? 2, 4, 5
• Moves DNA from one cell to another through conjugation? 4
• Moves protein from cytoplasm to exterior (not into another cell)? 1, 3
• Relies on Sec to do the first step of transportation? 2, 4, 5
• Requires ATP? All
• A domain of the protein itself forms a beta-barrel that inserts into the outer membrane (i.e., forming a pore), allowing the rest of the protein to pass through? 5
• The protein being transported carries a C-terminal signal peptide? 1
• The preprotein (before final folding) being transported carries an N-terminal signal peptide? Sec

Viral Multiplication

Six Steps to Viral Multiplication:

1. Attachment to host cell
2. Entry
3. Uncoating of genome
4. Synthesis
5. Assembly
6. Release

Microscopy

Definitions

Parfocal: Microscopes remain in focus when objectives are changed.

Refractive Index: A measure of how greatly a substance slows the velocity of light.

True/False

False: The bigger the "d", the higher the resolution.

Bacterial Structures

Hopanoids are abundant in bacteria.

Comparing Membrane Types

Integral membranes differ from peripheral membranes in that integral membranes are amphipathic and not easily removed.

Examples of Inclusion Bodies

• Granules of glycogen, poly-beta-hydroxybutyrate (PHB), as carbon storage
• Gas/vacuole/vesicle: Provide buoyancy for many cyanobacteria
• Magnetosomes: Contain magnetite, act as a homolog for the cytoskeleton

Virology

Charles Chamberland contributed to the field of virology by developing porcelain bacterial filters used later in the discovery of viruses.

Definitions

Plaques: Localized areas of cellular destruction and lysis caused by viral multiplication in the host.

True/False

False: A naked virus fuses with the host cell membrane.

Bacterial Transport and Metabolism

The best-known translocation system is the PTS (phosphoenolpyruvate: sugar phosphotransferase system). Bacteria use this system to transport sugars while phosphorylating them, using PEP as the phosphate donor.

Antibiotics

A broad-spectrum antibiotic is effective against a wide range of bacteria, including both gram-positive and gram-negative bacteria.