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Microscopes and Cells. Cells. Dutch cloth merchant and amateur scientist Anton van Leeuwenhoek found microscopic creatures in standing water. Using microscopes he made himself , Leeuwenhoek drew what he saw in pond water, plant material, even gunk scraped off his teeth.
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Cells Dutch cloth merchant and amateur scientist Anton van Leeuwenhoek found microscopic creatures in standing water. Using microscopes he made himself, Leeuwenhoek drew what he saw in pond water, plant material, even gunk scraped off his teeth. He was the first to identify sperm and red blood cells.
Best Known for coining the term “CELL” As “little room” • Hooke's cell drawing — This drawing, published in 1667, shows the cells Robert Hooke observed in a peice of cork wood that he looked at under a microscope. Courtesy National Library of Medicine. Robert Hooke
CELL THEORY Schwann Schleiden Virchow • states that all living things are composed of at least one cell and that the cell is the fundamental unit of function in all organisms. Corollaries: the chemical composition of all cells is fundamentally alike; all cells arise from preexisting cells through cell division. • All living things are made up of cells. • Cells are the basic units of structure and function in living things. • Living cells come only from other living cells.
All Cells Are Not Created Equal! All Cells have different types and amounts of organelles. The larger a cell becomes the more organelles it will need. A big cell will need more nourishment than a little cell. A larger cell would need to have more mitochondria to process food into energy.
Total Magnification is determined by multiplying the eyepiece power (usually 10x) by the objective lens in place. • For example, a 10x eyepiece and a 4x objective yields a total magnification of 40x (40 power).
Preparing a Wet Mount • Place it on the glass slide so as to look like (e). Place one drop of water on the specimen. • Cover it with a clean cover slip. • Turn on the microscope and place the slide on the stage; making sure the "e" is facing the normal reading position. • Using the course focus and low power, move the body tube down until the "e" can be seen clearly.
Staining Cells This picture was taken before staining, and it is harder to see • This picture was taken after staining
Transmission Electron Microscope (TEM) • Scanning Electron Microscope (SEM)
TEM Transmission Electron Microscopes Use electrons instead of light to create an image. The material prepared must be very thin and dead. The beams of electrons that pass through it give the viewer high magnification and resolution.
SEM A Scanning Electron Microscope uses electrons instead of light to create an image. These microscopes produce three-dimensional images with high resolution and magnification. They also have a larger depth of focus. Specimens do not have to be dead.
Bovine (cow) Pulmonary Artery Endothelial Cell Cancer Cell (Human)
Cedar Leaf Cedrus atlantica 200X Stamen and Pollen 125X
Animal Cell with mitochondria, ribosomes, chromatin, cytoplasm, endoplasmic reticulum, nucleolus TEM X 9,400
Nucleus and Nuclear Pores of Liver Cell (Animal Cell) TEM X 73,200. Ribosome, cytoplasm, Chromatin, nuclear pores
