electron microscope (EM)
endoplasmic reticulum (ER)
extracellular matrix (ECM)
light microscope (LM)
scanning electron microscope (SEM)
transmission electron microscope (TEM)
How We Study Cells
1. Know the brief history of cell study, the cell theory, and the scientists. 6
2. Know the different functions of the light microscope, transmission electron microscope,
and scanning electron microscope.
Light Microscope(LMs): Refracts(bends) the visible light passing through a
specimen such that a projected image is magnified.
Transmission electron microscope: (TEM) A beam of electrons is passed through a
thin section of a specimen stained with atoms of heavy metals , and electromagnets,
acting as lenses, focus the image onto a screen or film.
Electron Microscope(EM) : Focuses a beam of electrons through the specimen. The
short wavelength of the electron beam allows a resolution of about 2 nanometers ( a
hundred times greater than that of the light microscope.
Scanning Electron Microscope(SEM): an electron beam scans the surface of a
specimen usually coated with a thin gold film, exciting electrons from the specimen,
which are detected and translated into an image on a video screen. ( image appears
The Nucleus and Ribosomes
3. Know the structure and function of the nucleus, including the role of the pore
The nucleus contains most of the genes in the eukaryotic cell. (might want to look up
nuclear envelope, nucleolus, chromatin,and nuclear lamina.)
Pore Complex: An intricate protein structure that lines each pore and regulates
entry and exit of certain macromolecules and particles. ( Refer to page 103 Figure
4. Know the structure and function of ribosomes. Distinguish between free and bound
ribosomes in terms of location and function.
Ribosomes , particles made of ribosomal RNA and protein, are the organelles that
carry out protein synthesis.
(structure: non membranous organlle
cytoplasm or bound to rough ER or nuclear envelope.)
Free Bound: Suspended in the cytosol. Most of the proteins made on free ribosomes
function within the cytosol ( i.e. : enzymes that catalyze the first steps of sugar
Bound: Attached to the outside of the endoplasmic reticulum or nuclear envelope.
(generally make proteins that are destined either for insertion into membranes, for
packaging within certain organelles such as lysosomes or for export from the cell
(i.e. : cells of the pancreas have high proportion of them.)
The Endomembrane System
5. Compare the structure and functions of smooth and rough ER.
ribosomes. Important to synthesis of lipids(fats) , including oils,
This is the end of the preview. Sign up
access the rest of the document.