Cell Microscopic Functions - Chapter 4.1
BASIC INFORMATION
Most cells are between 1 and 100 um in diameter, too small to be seen by the unaided eye
LIGHT MICROSCOPES
Visible light is passed through a specimen and through glass lenses
Lenses refract (bend) the light, resulting into the image being magnified
3 IMPORTANT PARAMETERS OF MICROSCOPY
Magnification | The ratio of objects size to real size
Resolution | The measured of clarity of the image or the minimum distance between 2 points
Contrast | Visible differences in parts of the sample
MORE ON LIGHT MICROSCOPES
LMs can magnify effectively 1000 times the size of the specimen
Various techniques enhance contrast and enable cell components to be sustained or labeled
Most subcellular structures, including organelles, are toyo small to be resolved by the light microscopy
MICROSCOPES USED TO STUDY SUBCELLULAR STRUCTURES
Scanning electron microscopes (SEMs) focus a beam of electrons onto the surface of a specimen providing images that look 3D
Transmission electron microscopes (TEMs) focus a beam of electrons through a specimen
TEMs are mainly used to study the internal structure of cells
RECENT ADVANCES
Breaks up cells and separates the components using centrifugation
Cell components separate based on their relative size
Fractionation enables scientists to determine functions of organelles
Biochemistry and cytology help correlate cell function with structure
BASIC INFORMATION
Most cells are between 1 and 100 um in diameter, too small to be seen by the unaided eye
LIGHT MICROSCOPES
Visible light is passed through a specimen and through glass lenses
Lenses refract (bend) the light, resulting into the image being magnified
3 IMPORTANT PARAMETERS OF MICROSCOPY
Magnification | The ratio of objects size to real size
Resolution | The measured of clarity of the image or the minimum distance between 2 points
Contrast | Visible differences in parts of the sample
MORE ON LIGHT MICROSCOPES
LMs can magnify effectively 1000 times the size of the specimen
Various techniques enhance contrast and enable cell components to be sustained or labeled
Most subcellular structures, including organelles, are toyo small to be resolved by the light microscopy
MICROSCOPES USED TO STUDY SUBCELLULAR STRUCTURES
Scanning electron microscopes (SEMs) focus a beam of electrons onto the surface of a specimen providing images that look 3D
Transmission electron microscopes (TEMs) focus a beam of electrons through a specimen
TEMs are mainly used to study the internal structure of cells
RECENT ADVANCES
Breaks up cells and separates the components using centrifugation
Cell components separate based on their relative size
Fractionation enables scientists to determine functions of organelles
Biochemistry and cytology help correlate cell function with structure
