CELLS & CELLULAR
STRUCTURES
,Background
The cell is the basic structural & functional
unit of all living organisms
All living organisms consist of at least one
cell
Term “cell” coined by Robert Hooke in 1665
All cells develop from already existing cells
Almost all cells consist of a nucleus in
cytoplasm
All cells undergo metabolism
Similar molecules are found in all cells
,Microscopes
LM (light microscope) – used in class; light shines through object; lenses
enlarge & focus object up to 1000 × (HMB max 400 ×)
TEM (transmission electron microscope) – electrons move through
material (a beam of electrons is transmitted through an ultra thin
specimen, interacting with the specimen as it passes through. An image
is formed from the interaction of the electrons transmitted through the
specimen; the image is magnified and focused onto an imaging device,
such as a fluorescent screen, on a layer of photographic film, or to be
detected by a sensor such as a CCD camera.)
SEM (scanning electron microscope) – used to study the surface
structure of objects (electron microscope that images a sample by
scanning it with a high-energy beam of electrons in a raster scan
pattern. The electrons interact with the atoms that make up the sample
producing signals that contain information about the sample's surface
topography, composition, and other properties such as
electrical conductivity.)
,TEM ultrastructure of a liver cell
, SEM of an ant head
STRUCTURES
,Background
The cell is the basic structural & functional
unit of all living organisms
All living organisms consist of at least one
cell
Term “cell” coined by Robert Hooke in 1665
All cells develop from already existing cells
Almost all cells consist of a nucleus in
cytoplasm
All cells undergo metabolism
Similar molecules are found in all cells
,Microscopes
LM (light microscope) – used in class; light shines through object; lenses
enlarge & focus object up to 1000 × (HMB max 400 ×)
TEM (transmission electron microscope) – electrons move through
material (a beam of electrons is transmitted through an ultra thin
specimen, interacting with the specimen as it passes through. An image
is formed from the interaction of the electrons transmitted through the
specimen; the image is magnified and focused onto an imaging device,
such as a fluorescent screen, on a layer of photographic film, or to be
detected by a sensor such as a CCD camera.)
SEM (scanning electron microscope) – used to study the surface
structure of objects (electron microscope that images a sample by
scanning it with a high-energy beam of electrons in a raster scan
pattern. The electrons interact with the atoms that make up the sample
producing signals that contain information about the sample's surface
topography, composition, and other properties such as
electrical conductivity.)
,TEM ultrastructure of a liver cell
, SEM of an ant head
