Describe the principles, advantages, and limitations of the light microscope, transmission electron microscope, and scanning electron microscope.
Electron microscopes reveal organelles that are impossible to resolve with the light microscope. However, electron microscopes can only be used on dead cells.
•Light microscopes do not have as high a resolution, but they can be used to study live cells.
•Transmission electron microscopes (TEMs) are used mainly to study the internal ultrastructure of cells. A TEM aims an electron beam through a thin section of the specimen.
•Scanning electron microscopes (SEMs) are useful for studying surface structures. The SEM has great depth of field,resulting in an image that seems three-dimensional.
Explain why cell fractionation is a useful technique.
Enables scientist to determine the functions of organelles.
A Panoramic View of the Cell
Distinguish between prokaryotic and eukaryotic cells.
They both have: Plasma Membrane, Cytosol (semifluid subst), Chromosomes (carry genes), and Ribosomes (make proteins).
Prokaryotic: are small, simple, and NO nucleus or membrane-enclosed organelles, DNA is concentrated in the nucleoid w/o membrane separating it.
Eukaryotic: are big, complex, the chromosomes are contained within a membranous nuclear envelope, and numerous organelles suspended in the cytosol.
Explain the advantages of compartmentalization in eukaryotic cells.
They have both hydrophobic region tail and hydrophilic head. Head composed phosphate group attached to one carbon of glycerol is hydrophilic.
The Nucleus and Ribosomes
Describe the structure and function of the nuclear envelope, including the role of the pore complex.
Nuclear Envelope: a complex double membrane structure that encloses the nucleus. - Studded
