Microscopy and Bacterial Physiology

General Topics

The lecture focuses on readings from the week.
A quiz will be administered, covering the first reading, which is "How Microscopes Made Microbiology Possible" by Sung Lee.
The microscopy chapter from the microbiology book will not be covered due to time constraints.
The professor acknowledges that the material is still dense, despite efforts to simplify it.
Important aspects of microscopy in microbiology will be discussed, even though the dedicated microscopy chapter is omitted.

For viewing proteins, samples need to be crystallized.
GFP (Green Fluorescent Protein) is a key microscopy technique discussed.
- GFP was originally found in bacteria.
- It is now engineered to bind to specific targets like DNA or other proteins.
- GFP can be used to track movement within a cell.
- The process involves taking samples over time and observing them.
- This involves cutting cells and observing them internally.
- Samples are taken at different times to observe changes.
Electron microscopes use electrons, not photons, to illuminate samples.
- Therefore, the statement that electron microscopes use photons is false.

Three news articles will be discussed:
- "Treasure Hunt for Microbes in the Atacama Desert"
- "How Bacteria Swim" (focusing on the flagellum).
- "How Penicillin Eliminated Bacterial Physiology".
The discussion format will be similar to the previous session, but with more time for in-depth analysis.
The goal is to link the articles to concepts learned in Chapter 3, particularly concerning bacteria.

Students are divided into breakout rooms to answer specific questions related to the articles.
Room assignments:
- Rooms 1 & 2: Question 1
- Rooms 3 & 4: Question 2
- Rooms 5 & 6: Question 3
- Rooms 7 & 8: Question 4
- Rooms 9 & 10: Question 5
- Rooms 11 & 12: Question 6
Each group has approximately 20 minutes to discuss and answer their assigned question.

Question 3 involves designing a hypothetical experiment using cryo-EM to explore a new protein involved in bacterial motility.
The discussion references an article from Yale about using cryo-EM to visualize the structure of proteins involved in how bacteria swim.
Cryo-electron tomography is mentioned as a method for obtaining close-up images.
Not all bacteria use flagella for movement; some use other motor structures.
The hypothetical experiment should start by observing a bacterium's motility.
Cryo-EM would then be used to examine a new protein and how it interacts with the bacterium's structures related to movement.
The goal is to observe conformational changes in the protein and how these changes affect the bacteria's functions.
The experiment aims to understand the protein's role in the bacteria's mobility by analyzing its structure under cryo-EM.
It's noted that the protein's functions may not be well understood initially, as was the case in the Yale article.