Lecture 1 Flashcards
Who invented The Microscope?
Early microscopes did not look like modern compound microscopes.
Zacharias Jansen, together with his father Hans invesnted the first “microscope” in 1595.
It had multiple lenses attaced to a sliding tibe (so it was a “compound” microscope) to magnify the specimen
It has a magnification of ~9X
Robert C. Hooke
In 1655, Robert C. Hooke invented a microscope that could magnify 50X.
It had different ways to magnify specimens, different ways to shine light.
Described “cells” for the first time from a sample of cork.
Antonie Von Leeuwenhook
In 1674, Antonie Von Leeuwenhook used better lenses, but only a single spherical lens (so not a compound microscope) and invented a microscope that could magnify 230X.
What happened between 1831-1833?
Robert C. Brown described the cell nucleus using orchid cells.
What are the 3 main points of the cell theory?
1) All living organisms are composed of one of more cells
2) The cell is the basic unit of structure and organization in organisms
3) Cells arise from pre-existing cells
*Matthias Schleiden and Theodor Schwann identified the first 2
Robert Remak
Worked as an assistant to Johannes Peter Muller (a physiologist), but did it for free.
He worked as a physician to fund his work. All of his work was self-funded.
He figured out a way to harden and stain cells (copper sulfate, vinegar, alcohol).
Found the cell membrane (discovered that cells come from other cells (cell division)… but he didn’t get the credit)
Rudolf Virchow
Stole the idea and presented it as his own.
He got credit for Cell Theory
Albert von Kolliker
In 1857, he “discovered” mitochondria (sort of).
He saw “granules” in muscle cells (happened to be mitochondria).
Richard Altmann
In 1886, he used dyes and called them “granules”… “bioblasts”
Carl Benda
In 1898, he coined the term mitochondria.
What is mitochondria derived from?
Derived from the Greek for the words thread (mitos), and granule (chondros).
Camillio Golgi
In 1898, he characterized the Golgi apparatus.
Golgi had to leave hia lab (financial problems).
Got a job as chief medical officer in a mental hospital.
Started a lab in his kitchen at home.
What did Camillio Golgi invent?
He invented the staining technique called the “Dark Reaction” that stained individual nerve cells (AKA The Black Reaction, The Golgi Stain, The Golgi Method)
Found a network in the cells that he called the “internal reticular apparatus”.
This was challenged by the field as the stain could just be a staining artifacts.
When electron microscopy was invented, the Golgi apparatus organelles was clearly visuaalized and named for Golgi.
Got Nobel prize (1906) NOT for discovering the Golgi apparatus but rather for the dark reaction.
How does the staining technique “Dark Reaction” work?
Fix the sample (with formaldehyde [as Golgi did] or paraformaldehyde or glutaraldehyde or a combination of them)
Put the sample in a solution of 2% potassium dichromate for 2 days
Dry the sample with filter paper
Put the sample in a solution of 2% silver nitrate for 2 days
Cut tissue sections
Dehydrate the sample using ethanol
Mount coverslip
Look on microscope
What you see is the microcrystalization of silver chromate in the neurons
What has been learned about this technique?
The technique has been honed since Golgi invented it. Using gold instead of silver to get finer structural details.
This ultimately led to the formation of the “Neuron Theory” (AKA Neuron Doctrine)
Golgi’s technique (the Dark Reaction) also let him see other things (eg. what we now know as the Golgi apparatus)
