Cells and Microscopy Flashcards
Light Microscope
An optical instrument with lenses that refract visible light to magnify images and project them into a viewers’ eye or film
what are most cells diameters
between 1 and 100 micrometers
Resolution
a measure of the clarity of an image
cell theory
the theory that all living things are composed of cells and that all cells come from other cells
The maximum size of a cell needs to have a surface area,,,
large enough to service the volume of a cell
what does plasma membrane consist of
phospholipid bilayer and embedded proteins
Identify the parts of a basic light microscope and describe the function of each.
Eyepiece: contains the ocular lens, which provides a magnification power of 10x to 15x, usually. This is where you look through.
Nosepiece: holds the objective lenses and can be rotated easily to change magnification.
Objective lenses: usually, there are three or four objective lenses on a microscope, consisting of 4x, 10x, 40x and 100x magnification powers. In order to obtain the total magnification of an image, you need to multiply the eyepiece lens power by the objective lens power. So, if you couple a 10x eyepiece lens with a 40x objective lens, the total magnification is of 10 x 40 = 400 times.
Stage clips: hold the slide in place.
Stage: it is a flat platform that supports the slide being analyzed.
Diaphragm: it controls the intensity and size of the cone light projected on the specimen. As a rule of thumb, the more transparent the specimen, less light is required.
Light source: it projects light upwards through the diaphragm, slide and lenses.
Base: supports the microscope.
Arm: supports the microscope when carried.
Coarse adjustment knob: when the knob is turned, the stage moves up or down, in order to coarse adjust the focus.
Fine adjustment knob: used fine adjust the focus.
Outline the tenets of the cell theory.
- All living things are made of cells
- All cells come from other cells
- Cells are the smallest unit of life
Explain why there are limits to cell size.
They can’t get super big because they will then divide and produce other cells by that division
Outline the differences between prokaryote and eukaryote cells.
Prokaryotic Cells: A cell having no membrane enclosed nucleus and is only found in bacteria and archaea
Eukaryotic Cells: A cell containing a nucleus and are found in any all other living organisms
Define “organelle.”
any of a number of organized or specialized structures within a living cell. Found in Eukaryotic and Prokaryotic Cells in their cytoplasm
Outline the differences between plant and animal cells.
They are similar in size even though animal cells can be bigger. Other than that, plant cells can contain chloroplast, a cell wall, and vacuoles.
Describe the structure and function of the plasma membrane.
Acts as a selective barrier in the passage of ions and molecules in and out of the cell. It consists of a phospholipid bilayer and embedded proteins
Explain the function of the cytoskeleton.
Provides shape, movement, and anchorage of organelles
Describe the three basic types of fibers that make up the cytoskeleton
Microtubules are the thickest kinds of fiber in the cytoskeleton and it is a hollow tune made up of globvial proteins called tubulins
Intermediate Filaments are a medium sized protein fiber in the cytoskeleton and are rope like and are to reinforce shape and anchor organelles
Microfilaments are the thinnest of the proteins in the cytoskeleton and are arranged in a twisted double chain, they are involved in cell movements
