Cell Theory- in the 18th century, two scientists came up with the cell theory. Schleiden and Schwen.
3 corollaries of the cell theory:
-all cells are alike in chemical composition
-all cells store and process information in the same way
-all cells arise from other cell through cell division
5 types of different Microscopes
1. Light Microscope- produces 2-D image
Direct descendants of Hooks scope> take two lenses to a light source> used this to magnify images up to 1,000 fold.
2. Confocal Microscope- uses lenses& a light source> produces a 3-D image.
3. Fluorescence Microscope- 2-D or 3-D, allows us to visualize fluorescent dyes.
4. Transmission Electron Microscope- it shoots a bean of electrons through a sample, and it collects whatever passes through.
-It can do a million fold magnifications.
2-D images, visualize down to 2nm(nanometers)
1mm=1000mm(micrometers)
1mm=1000nm
5. Scanning Electron Microscope- Functions in a similar function to a transmission electron microscope> 3-D images, 3-20 nm in size.
What does it mean to be alive?
All living things are composed of cells.
Cell
Cells are the basic unit of life. A small membrane enclosed unit with a concentrated aqueous solution of chemicals. It’s endowed with the ability to copy itself.
-Every living thing is composed of a colony of cells that began as a single cell.
DNA> (transcription)>RNA> (translation)>Protein
Visualization of Cells
-1665 Robert Hooke (professional lens maker, scientist)
He developed a primitive microscope, used it to observe cork. He sees a series of chambers. Actually what Hooke is seeing, is the cell wall of a dead flower that had been near the cork.
Cells vary in size and shape. Generally the diameter of a cell falls between 0,5mm (micrometers) -30mm.
Larger cells: Frog Eggs: 1.5mm
Ostritch Egg: 152mm in diameter
Cells are diverse in their chemical requirements that cells need to stay alive.
Ex: Some cells require oxygen for life/ Other